org.apache.spark.sql

Class DataFrameReader

Object

org.apache.spark.sql.DataFrameReader

All Implemented Interfaces:

org.apache.spark.internal.Logging

public class DataFrameReader
extends Object
implements org.apache.spark.internal.Logging

Interface used to load a Dataset from external storage systems (e.g. file systems, key-value stores, etc). Use SparkSession.read to access this.

Since:

1.4.0

Method Summary

Modifier and Type	Method and Description
Dataset<Row>	csv(Dataset<String> csvDataset) Loads an Dataset[String] storing CSV rows and returns the result as a DataFrame.
Dataset<Row>	csv(scala.collection.Seq<String> paths) Loads CSV files and returns the result as a DataFrame.
Dataset<Row>	csv(String... paths) Loads CSV files and returns the result as a DataFrame.
Dataset<Row>	csv(String path) Loads a CSV file and returns the result as a DataFrame.
DataFrameReader	format(String source) Specifies the input data source format.
Dataset<Row>	jdbc(String url, String table, java.util.Properties properties) Construct a DataFrame representing the database table accessible via JDBC URL url named table and connection properties.
Dataset<Row>	jdbc(String url, String table, String[] predicates, java.util.Properties connectionProperties) Construct a DataFrame representing the database table accessible via JDBC URL url named table using connection properties.
Dataset<Row>	jdbc(String url, String table, String columnName, long lowerBound, long upperBound, int numPartitions, java.util.Properties connectionProperties) Construct a DataFrame representing the database table accessible via JDBC URL url named table.
Dataset<Row>	json(Dataset<String> jsonDataset) Loads a Dataset[String] storing JSON objects (JSON Lines text format or newline-delimited JSON) and returns the result as a DataFrame.
Dataset<Row>	json(JavaRDD<String> jsonRDD) Deprecated. Use json(Dataset[String]) instead. Since 2.2.0.
Dataset<Row>	json(RDD<String> jsonRDD) Deprecated. Use json(Dataset[String]) instead. Since 2.2.0.
Dataset<Row>	json(scala.collection.Seq<String> paths) Loads JSON files and returns the results as a DataFrame.
Dataset<Row>	json(String... paths) Loads JSON files and returns the results as a DataFrame.
Dataset<Row>	json(String path) Loads a JSON file and returns the results as a DataFrame.
Dataset<Row>	load() Loads input in as a DataFrame, for data sources that don't require a path (e.g.
Dataset<Row>	load(scala.collection.Seq<String> paths) Loads input in as a DataFrame, for data sources that support multiple paths.
Dataset<Row>	load(String... paths) Loads input in as a DataFrame, for data sources that support multiple paths.
Dataset<Row>	load(String path) Loads input in as a DataFrame, for data sources that require a path (e.g.
DataFrameReader	option(String key, boolean value) Adds an input option for the underlying data source.
DataFrameReader	option(String key, double value) Adds an input option for the underlying data source.
DataFrameReader	option(String key, long value) Adds an input option for the underlying data source.
DataFrameReader	option(String key, String value) Adds an input option for the underlying data source.
DataFrameReader	options(scala.collection.Map<String,String> options) (Scala-specific) Adds input options for the underlying data source.
DataFrameReader	options(java.util.Map<String,String> options) Adds input options for the underlying data source.
Dataset<Row>	orc(scala.collection.Seq<String> paths) Loads ORC files and returns the result as a DataFrame.
Dataset<Row>	orc(String... paths) Loads ORC files and returns the result as a DataFrame.
Dataset<Row>	orc(String path) Loads an ORC file and returns the result as a DataFrame.
Dataset<Row>	parquet(scala.collection.Seq<String> paths) Loads a Parquet file, returning the result as a DataFrame.
Dataset<Row>	parquet(String... paths) Loads a Parquet file, returning the result as a DataFrame.
Dataset<Row>	parquet(String path) Loads a Parquet file, returning the result as a DataFrame.
DataFrameReader	schema(String schemaString) Specifies the schema by using the input DDL-formatted string.
DataFrameReader	schema(StructType schema) Specifies the input schema.
Dataset<Row>	table(String tableName) Returns the specified table/view as a DataFrame.
Dataset<Row>	text(scala.collection.Seq<String> paths) Loads text files and returns a DataFrame whose schema starts with a string column named "value", and followed by partitioned columns if there are any.
Dataset<Row>	text(String... paths) Loads text files and returns a DataFrame whose schema starts with a string column named "value", and followed by partitioned columns if there are any.
Dataset<Row>	text(String path) Loads text files and returns a DataFrame whose schema starts with a string column named "value", and followed by partitioned columns if there are any.
Dataset<String>	textFile(scala.collection.Seq<String> paths) Loads text files and returns a Dataset of String.
Dataset<String>	textFile(String... paths) Loads text files and returns a Dataset of String.
Dataset<String>	textFile(String path) Loads text files and returns a Dataset of String.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.spark.internal.Logging

$init$, initializeForcefully, initializeLogIfNecessary, initializeLogIfNecessary, initializeLogIfNecessary$default$2, initLock, isTraceEnabled, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning, org$apache$spark$internal$Logging$$log__$eq, org$apache$spark$internal$Logging$$log_, uninitialize

Method Detail

csv

public Dataset<Row> csv(String... paths)

Loads CSV files and returns the result as a DataFrame.

This function will go through the input once to determine the input schema if inferSchema is enabled. To avoid going through the entire data once, disable inferSchema option or specify the schema explicitly using schema.

You can set the following CSV-specific options to deal with CSV files:

• sep (default ,): sets a separator for each field and value. This separator can be one or more characters.
• encoding (default UTF-8): decodes the CSV files by the given encoding type.
• quote (default "): sets a single character used for escaping quoted values where the separator can be part of the value. If you would like to turn off quotations, you need to set not null but an empty string. This behaviour is different from com.databricks.spark.csv.
• escape (default \): sets a single character used for escaping quotes inside an already quoted value.
• charToEscapeQuoteEscaping (default escape or \0): sets a single character used for escaping the escape for the quote character. The default value is escape character when escape and quote characters are different, \0 otherwise.
• comment (default empty string): sets a single character used for skipping lines beginning with this character. By default, it is disabled.
• header (default false): uses the first line as names of columns.
• enforceSchema (default true): If it is set to true, the specified or inferred schema will be forcibly applied to datasource files, and headers in CSV files will be ignored. If the option is set to false, the schema will be validated against all headers in CSV files in the case when the header option is set to true. Field names in the schema and column names in CSV headers are checked by their positions taking into account spark.sql.caseSensitive. Though the default value is true, it is recommended to disable the enforceSchema option to avoid incorrect results.
• inferSchema (default false): infers the input schema automatically from data. It requires one extra pass over the data.
• samplingRatio (default is 1.0): defines fraction of rows used for schema inferring.
• ignoreLeadingWhiteSpace (default false): a flag indicating whether or not leading whitespaces from values being read should be skipped.
• ignoreTrailingWhiteSpace (default false): a flag indicating whether or not trailing whitespaces from values being read should be skipped.
• nullValue (default empty string): sets the string representation of a null value. Since 2.0.1, this applies to all supported types including the string type.
• emptyValue (default empty string): sets the string representation of an empty value.
• nanValue (default NaN): sets the string representation of a non-number" value.
• positiveInf (default Inf): sets the string representation of a positive infinity value.
• negativeInf (default -Inf): sets the string representation of a negative infinity value.
• dateFormat (default yyyy-MM-dd): sets the string that indicates a date format. Custom date formats follow the formats at Datetime Patterns. This applies to date type.
• timestampFormat (default yyyy-MM-dd'T'HH:mm:ss[.SSS][XXX]): sets the string that indicates a timestamp format. Custom date formats follow the formats at Datetime Patterns. This applies to timestamp type.
• maxColumns (default 20480): defines a hard limit of how many columns a record can have.
• maxCharsPerColumn (default -1): defines the maximum number of characters allowed for any given value being read. By default, it is -1 meaning unlimited length
• unescapedQuoteHandling (default STOP_AT_DELIMITER): defines how the CsvParser will handle values with unescaped quotes.
  • STOP_AT_CLOSING_QUOTE: If unescaped quotes are found in the input, accumulate the quote character and proceed parsing the value as a quoted value, until a closing quote is found.
  • BACK_TO_DELIMITER: If unescaped quotes are found in the input, consider the value as an unquoted value. This will make the parser accumulate all characters of the current parsed value until the delimiter is found. If no delimiter is found in the value, the parser will continue accumulating characters from the input until a delimiter or line ending is found.
  • STOP_AT_DELIMITER: If unescaped quotes are found in the input, consider the value as an unquoted value. This will make the parser accumulate all characters until the delimiter or a line ending is found in the input.
  • STOP_AT_DELIMITER: If unescaped quotes are found in the input, the content parsed for the given value will be skipped and the value set in nullValue will be produced instead.
  • RAISE_ERROR: If unescaped quotes are found in the input, a TextParsingException will be thrown.
• mode (default PERMISSIVE): allows a mode for dealing with corrupt records during parsing. It supports the following case-insensitive modes. Note that Spark tries to parse only required columns in CSV under column pruning. Therefore, corrupt records can be different based on required set of fields. This behavior can be controlled by spark.sql.csv.parser.columnPruning.enabled (enabled by default).
  • PERMISSIVE : when it meets a corrupted record, puts the malformed string into a field configured by columnNameOfCorruptRecord, and sets malformed fields to null. To keep corrupt records, an user can set a string type field named columnNameOfCorruptRecord in an user-defined schema. If a schema does not have the field, it drops corrupt records during parsing. A record with less/more tokens than schema is not a corrupted record to CSV. When it meets a record having fewer tokens than the length of the schema, sets null to extra fields. When the record has more tokens than the length of the schema, it drops extra tokens.
  • DROPMALFORMED : ignores the whole corrupted records.
  • FAILFAST : throws an exception when it meets corrupted records.
• columnNameOfCorruptRecord (default is the value specified in spark.sql.columnNameOfCorruptRecord): allows renaming the new field having malformed string created by PERMISSIVE mode. This overrides spark.sql.columnNameOfCorruptRecord.
• multiLine (default false): parse one record, which may span multiple lines.
• locale (default is en-US): sets a locale as language tag in IETF BCP 47 format. For instance, this is used while parsing dates and timestamps.
• lineSep (default covers all \r, \r\n and \n): defines the line separator that should be used for parsing. Maximum length is 1 character.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

csv

public Dataset<Row> csv(String path)

Loads a CSV file and returns the result as a DataFrame. See the documentation on the other overloaded csv() method for more details.

Parameters:

path - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

csv

public Dataset<Row> csv(Dataset<String> csvDataset)

Loads an Dataset[String] storing CSV rows and returns the result as a DataFrame.

If the schema is not specified using schema function and inferSchema option is enabled, this function goes through the input once to determine the input schema.

If the schema is not specified using schema function and inferSchema option is disabled, it determines the columns as string types and it reads only the first line to determine the names and the number of fields.

If the enforceSchema is set to false, only the CSV header in the first line is checked to conform specified or inferred schema.

Parameters:

csvDataset - input Dataset with one CSV row per record

Returns:

(undocumented)

Since:

2.2.0

Note:

if header option is set to true when calling this API, all lines same with the header will be removed if exists.

csv

public Dataset<Row> csv(scala.collection.Seq<String> paths)

Loads CSV files and returns the result as a DataFrame.

This function will go through the input once to determine the input schema if inferSchema is enabled. To avoid going through the entire data once, disable inferSchema option or specify the schema explicitly using schema.

You can set the following CSV-specific options to deal with CSV files:

• sep (default ,): sets a separator for each field and value. This separator can be one or more characters.
• encoding (default UTF-8): decodes the CSV files by the given encoding type.
• quote (default "): sets a single character used for escaping quoted values where the separator can be part of the value. If you would like to turn off quotations, you need to set not null but an empty string. This behaviour is different from com.databricks.spark.csv.
• escape (default \): sets a single character used for escaping quotes inside an already quoted value.
• charToEscapeQuoteEscaping (default escape or \0): sets a single character used for escaping the escape for the quote character. The default value is escape character when escape and quote characters are different, \0 otherwise.
• comment (default empty string): sets a single character used for skipping lines beginning with this character. By default, it is disabled.
• header (default false): uses the first line as names of columns.
• enforceSchema (default true): If it is set to true, the specified or inferred schema will be forcibly applied to datasource files, and headers in CSV files will be ignored. If the option is set to false, the schema will be validated against all headers in CSV files in the case when the header option is set to true. Field names in the schema and column names in CSV headers are checked by their positions taking into account spark.sql.caseSensitive. Though the default value is true, it is recommended to disable the enforceSchema option to avoid incorrect results.
• inferSchema (default false): infers the input schema automatically from data. It requires one extra pass over the data.
• samplingRatio (default is 1.0): defines fraction of rows used for schema inferring.
• ignoreLeadingWhiteSpace (default false): a flag indicating whether or not leading whitespaces from values being read should be skipped.
• ignoreTrailingWhiteSpace (default false): a flag indicating whether or not trailing whitespaces from values being read should be skipped.
• nullValue (default empty string): sets the string representation of a null value. Since 2.0.1, this applies to all supported types including the string type.
• emptyValue (default empty string): sets the string representation of an empty value.
• nanValue (default NaN): sets the string representation of a non-number" value.
• positiveInf (default Inf): sets the string representation of a positive infinity value.
• negativeInf (default -Inf): sets the string representation of a negative infinity value.
• dateFormat (default yyyy-MM-dd): sets the string that indicates a date format. Custom date formats follow the formats at Datetime Patterns. This applies to date type.
• timestampFormat (default yyyy-MM-dd'T'HH:mm:ss[.SSS][XXX]): sets the string that indicates a timestamp format. Custom date formats follow the formats at Datetime Patterns. This applies to timestamp type.
• maxColumns (default 20480): defines a hard limit of how many columns a record can have.
• maxCharsPerColumn (default -1): defines the maximum number of characters allowed for any given value being read. By default, it is -1 meaning unlimited length
• unescapedQuoteHandling (default STOP_AT_DELIMITER): defines how the CsvParser will handle values with unescaped quotes.
  • STOP_AT_CLOSING_QUOTE: If unescaped quotes are found in the input, accumulate the quote character and proceed parsing the value as a quoted value, until a closing quote is found.
  • BACK_TO_DELIMITER: If unescaped quotes are found in the input, consider the value as an unquoted value. This will make the parser accumulate all characters of the current parsed value until the delimiter is found. If no delimiter is found in the value, the parser will continue accumulating characters from the input until a delimiter or line ending is found.
  • STOP_AT_DELIMITER: If unescaped quotes are found in the input, consider the value as an unquoted value. This will make the parser accumulate all characters until the delimiter or a line ending is found in the input.
  • STOP_AT_DELIMITER: If unescaped quotes are found in the input, the content parsed for the given value will be skipped and the value set in nullValue will be produced instead.
  • RAISE_ERROR: If unescaped quotes are found in the input, a TextParsingException will be thrown.
• mode (default PERMISSIVE): allows a mode for dealing with corrupt records during parsing. It supports the following case-insensitive modes. Note that Spark tries to parse only required columns in CSV under column pruning. Therefore, corrupt records can be different based on required set of fields. This behavior can be controlled by spark.sql.csv.parser.columnPruning.enabled (enabled by default).
  • PERMISSIVE : when it meets a corrupted record, puts the malformed string into a field configured by columnNameOfCorruptRecord, and sets malformed fields to null. To keep corrupt records, an user can set a string type field named columnNameOfCorruptRecord in an user-defined schema. If a schema does not have the field, it drops corrupt records during parsing. A record with less/more tokens than schema is not a corrupted record to CSV. When it meets a record having fewer tokens than the length of the schema, sets null to extra fields. When the record has more tokens than the length of the schema, it drops extra tokens.
  • DROPMALFORMED : ignores the whole corrupted records.
  • FAILFAST : throws an exception when it meets corrupted records.
• columnNameOfCorruptRecord (default is the value specified in spark.sql.columnNameOfCorruptRecord): allows renaming the new field having malformed string created by PERMISSIVE mode. This overrides spark.sql.columnNameOfCorruptRecord.
• multiLine (default false): parse one record, which may span multiple lines.
• locale (default is en-US): sets a locale as language tag in IETF BCP 47 format. For instance, this is used while parsing dates and timestamps.
• lineSep (default covers all \r, \r\n and \n): defines the line separator that should be used for parsing. Maximum length is 1 character.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

format

public DataFrameReader format(String source)

Specifies the input data source format.

Parameters:

source - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

jdbc

public Dataset<Row> jdbc(String url,
                         String table,
                         java.util.Properties properties)

Construct a DataFrame representing the database table accessible via JDBC URL url named table and connection properties.

Parameters:

url - (undocumented)

table - (undocumented)

properties - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

jdbc

public Dataset<Row> jdbc(String url,
                         String table,
                         String columnName,
                         long lowerBound,
                         long upperBound,
                         int numPartitions,
                         java.util.Properties connectionProperties)

Construct a DataFrame representing the database table accessible via JDBC URL url named table. Partitions of the table will be retrieved in parallel based on the parameters passed to this function.

Don't create too many partitions in parallel on a large cluster; otherwise Spark might crash your external database systems.

Parameters:

url - JDBC database url of the form jdbc:subprotocol:subname.

table - Name of the table in the external database.

columnName - the name of a column of numeric, date, or timestamp type that will be used for partitioning.

lowerBound - the minimum value of columnName used to decide partition stride.

upperBound - the maximum value of columnName used to decide partition stride.

numPartitions - the number of partitions. This, along with lowerBound (inclusive), upperBound (exclusive), form partition strides for generated WHERE clause expressions used to split the column columnName evenly. When the input is less than 1, the number is set to 1.

connectionProperties - JDBC database connection arguments, a list of arbitrary string tag/value. Normally at least a "user" and "password" property should be included. "fetchsize" can be used to control the number of rows per fetch and "queryTimeout" can be used to wait for a Statement object to execute to the given number of seconds.

Returns:

(undocumented)

Since:

1.4.0

jdbc

public Dataset<Row> jdbc(String url,
                         String table,
                         String[] predicates,
                         java.util.Properties connectionProperties)

Construct a DataFrame representing the database table accessible via JDBC URL url named table using connection properties. The predicates parameter gives a list expressions suitable for inclusion in WHERE clauses; each one defines one partition of the DataFrame.

Don't create too many partitions in parallel on a large cluster; otherwise Spark might crash your external database systems.

Parameters:

url - JDBC database url of the form jdbc:subprotocol:subname

table - Name of the table in the external database.

predicates - Condition in the where clause for each partition.

connectionProperties - JDBC database connection arguments, a list of arbitrary string tag/value. Normally at least a "user" and "password" property should be included. "fetchsize" can be used to control the number of rows per fetch.

Returns:

(undocumented)

Since:

1.4.0

json

public Dataset<Row> json(String... paths)

Loads JSON files and returns the results as a DataFrame.

JSON Lines (newline-delimited JSON) is supported by default. For JSON (one record per file), set the multiLine option to true.

This function goes through the input once to determine the input schema. If you know the schema in advance, use the version that specifies the schema to avoid the extra scan.

You can set the following JSON-specific options to deal with non-standard JSON files:

• primitivesAsString (default false): infers all primitive values as a string type
• prefersDecimal (default false): infers all floating-point values as a decimal type. If the values do not fit in decimal, then it infers them as doubles.
• allowComments (default false): ignores Java/C++ style comment in JSON records
• allowUnquotedFieldNames (default false): allows unquoted JSON field names
• allowSingleQuotes (default true): allows single quotes in addition to double quotes
• allowNumericLeadingZeros (default false): allows leading zeros in numbers (e.g. 00012)
• allowBackslashEscapingAnyCharacter (default false): allows accepting quoting of all character using backslash quoting mechanism
• allowUnquotedControlChars (default false): allows JSON Strings to contain unquoted control characters (ASCII characters with value less than 32, including tab and line feed characters) or not.
• mode (default PERMISSIVE): allows a mode for dealing with corrupt records during parsing.
  • PERMISSIVE : when it meets a corrupted record, puts the malformed string into a field configured by columnNameOfCorruptRecord, and sets malformed fields to null. To keep corrupt records, an user can set a string type field named columnNameOfCorruptRecord in an user-defined schema. If a schema does not have the field, it drops corrupt records during parsing. When inferring a schema, it implicitly adds a columnNameOfCorruptRecord field in an output schema.
  • DROPMALFORMED : ignores the whole corrupted records.
  • FAILFAST : throws an exception when it meets corrupted records.
• columnNameOfCorruptRecord (default is the value specified in spark.sql.columnNameOfCorruptRecord): allows renaming the new field having malformed string created by PERMISSIVE mode. This overrides spark.sql.columnNameOfCorruptRecord.
• dateFormat (default yyyy-MM-dd): sets the string that indicates a date format. Custom date formats follow the formats at Datetime Patterns. This applies to date type.
• timestampFormat (default yyyy-MM-dd'T'HH:mm:ss[.SSS][XXX]): sets the string that indicates a timestamp format. Custom date formats follow the formats at Datetime Patterns. This applies to timestamp type.
• multiLine (default false): parse one record, which may span multiple lines, per file
• encoding (by default it is not set): allows to forcibly set one of standard basic or extended encoding for the JSON files. For example UTF-16BE, UTF-32LE. If the encoding is not specified and multiLine is set to true, it will be detected automatically.
• lineSep (default covers all \r, \r\n and \n): defines the line separator that should be used for parsing.
• samplingRatio (default is 1.0): defines fraction of input JSON objects used for schema inferring.
• dropFieldIfAllNull (default false): whether to ignore column of all null values or empty array/struct during schema inference.
• locale (default is en-US): sets a locale as language tag in IETF BCP 47 format. For instance, this is used while parsing dates and timestamps.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery
• allowNonNumericNumbers (default true): allows JSON parser to recognize set of "Not-a-Number" (NaN) tokens as legal floating number values:
  • +INF for positive infinity, as well as alias of +Infinity and Infinity.
  • -INF for negative infinity), alias -Infinity.
  • NaN for other not-a-numbers, like result of division by zero.

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

json

public Dataset<Row> json(String path)

Loads a JSON file and returns the results as a DataFrame.

See the documentation on the overloaded json() method with varargs for more details.

Parameters:

path - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

json

public Dataset<Row> json(scala.collection.Seq<String> paths)

Loads JSON files and returns the results as a DataFrame.

JSON Lines (newline-delimited JSON) is supported by default. For JSON (one record per file), set the multiLine option to true.

This function goes through the input once to determine the input schema. If you know the schema in advance, use the version that specifies the schema to avoid the extra scan.

You can set the following JSON-specific options to deal with non-standard JSON files:

• primitivesAsString (default false): infers all primitive values as a string type
• prefersDecimal (default false): infers all floating-point values as a decimal type. If the values do not fit in decimal, then it infers them as doubles.
• allowComments (default false): ignores Java/C++ style comment in JSON records
• allowUnquotedFieldNames (default false): allows unquoted JSON field names
• allowSingleQuotes (default true): allows single quotes in addition to double quotes
• allowNumericLeadingZeros (default false): allows leading zeros in numbers (e.g. 00012)
• allowBackslashEscapingAnyCharacter (default false): allows accepting quoting of all character using backslash quoting mechanism
• allowUnquotedControlChars (default false): allows JSON Strings to contain unquoted control characters (ASCII characters with value less than 32, including tab and line feed characters) or not.
• mode (default PERMISSIVE): allows a mode for dealing with corrupt records during parsing.
  • PERMISSIVE : when it meets a corrupted record, puts the malformed string into a field configured by columnNameOfCorruptRecord, and sets malformed fields to null. To keep corrupt records, an user can set a string type field named columnNameOfCorruptRecord in an user-defined schema. If a schema does not have the field, it drops corrupt records during parsing. When inferring a schema, it implicitly adds a columnNameOfCorruptRecord field in an output schema.
  • DROPMALFORMED : ignores the whole corrupted records.
  • FAILFAST : throws an exception when it meets corrupted records.
• columnNameOfCorruptRecord (default is the value specified in spark.sql.columnNameOfCorruptRecord): allows renaming the new field having malformed string created by PERMISSIVE mode. This overrides spark.sql.columnNameOfCorruptRecord.
• dateFormat (default yyyy-MM-dd): sets the string that indicates a date format. Custom date formats follow the formats at Datetime Patterns. This applies to date type.
• timestampFormat (default yyyy-MM-dd'T'HH:mm:ss[.SSS][XXX]): sets the string that indicates a timestamp format. Custom date formats follow the formats at Datetime Patterns. This applies to timestamp type.
• multiLine (default false): parse one record, which may span multiple lines, per file
• encoding (by default it is not set): allows to forcibly set one of standard basic or extended encoding for the JSON files. For example UTF-16BE, UTF-32LE. If the encoding is not specified and multiLine is set to true, it will be detected automatically.
• lineSep (default covers all \r, \r\n and \n): defines the line separator that should be used for parsing.
• samplingRatio (default is 1.0): defines fraction of input JSON objects used for schema inferring.
• dropFieldIfAllNull (default false): whether to ignore column of all null values or empty array/struct during schema inference.
• locale (default is en-US): sets a locale as language tag in IETF BCP 47 format. For instance, this is used while parsing dates and timestamps.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery
• allowNonNumericNumbers (default true): allows JSON parser to recognize set of "Not-a-Number" (NaN) tokens as legal floating number values:
  • +INF for positive infinity, as well as alias of +Infinity and Infinity.
  • -INF for negative infinity), alias -Infinity.
  • NaN for other not-a-numbers, like result of division by zero.

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

json

public Dataset<Row> json(JavaRDD<String> jsonRDD)

Deprecated. Use json(Dataset[String]) instead. Since 2.2.0.

Loads a JavaRDD[String] storing JSON objects (JSON Lines text format or newline-delimited JSON) and returns the result as a DataFrame.

Unless the schema is specified using schema function, this function goes through the input once to determine the input schema.

Parameters:

jsonRDD - input RDD with one JSON object per record

Returns:

(undocumented)

Since:

1.4.0

json

public Dataset<Row> json(RDD<String> jsonRDD)

Deprecated. Use json(Dataset[String]) instead. Since 2.2.0.

Loads an RDD[String] storing JSON objects (JSON Lines text format or newline-delimited JSON) and returns the result as a DataFrame.

Unless the schema is specified using schema function, this function goes through the input once to determine the input schema.

Parameters:

jsonRDD - input RDD with one JSON object per record

Returns:

(undocumented)

Since:

1.4.0

json

public Dataset<Row> json(Dataset<String> jsonDataset)

Loads a Dataset[String] storing JSON objects (JSON Lines text format or newline-delimited JSON) and returns the result as a DataFrame.

Unless the schema is specified using schema function, this function goes through the input once to determine the input schema.

Parameters:

jsonDataset - input Dataset with one JSON object per record

Returns:

(undocumented)

Since:

2.2.0

load

public Dataset<Row> load(String... paths)

Loads input in as a DataFrame, for data sources that support multiple paths. Only works if the source is a HadoopFsRelationProvider.

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

1.6.0

load

public Dataset<Row> load()

Loads input in as a DataFrame, for data sources that don't require a path (e.g. external key-value stores).

Returns:

(undocumented)

Since:

1.4.0

load

public Dataset<Row> load(String path)

Loads input in as a DataFrame, for data sources that require a path (e.g. data backed by a local or distributed file system).

Parameters:

path - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

load

public Dataset<Row> load(scala.collection.Seq<String> paths)

Loads input in as a DataFrame, for data sources that support multiple paths. Only works if the source is a HadoopFsRelationProvider.

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

1.6.0

option

public DataFrameReader option(String key,
                              String value)

Adds an input option for the underlying data source.

All options are maintained in a case-insensitive way in terms of key names. If a new option has the same key case-insensitively, it will override the existing option.

You can set the following option(s):

• timeZone (default session local timezone): sets the string that indicates a time zone ID to be used to parse timestamps in the JSON/CSV datasources or partition values. The following formats of timeZone are supported:
  • Region-based zone ID: It should have the form 'area/city', such as 'America/Los_Angeles'.
  • Zone offset: It should be in the format '(+|-)HH:mm', for example '-08:00' or '+01:00'. Also 'UTC' and 'Z' are supported as aliases of '+00:00'.
  Other short names like 'CST' are not recommended to use because they can be ambiguous. If it isn't set, the current value of the SQL config spark.sql.session.timeZone is used by default.

Parameters:

key - (undocumented)

value - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

option

public DataFrameReader option(String key,
                              boolean value)

Adds an input option for the underlying data source.

All options are maintained in a case-insensitive way in terms of key names. If a new option has the same key case-insensitively, it will override the existing option.

Parameters:

key - (undocumented)

value - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

option

public DataFrameReader option(String key,
                              long value)

Adds an input option for the underlying data source.

All options are maintained in a case-insensitive way in terms of key names. If a new option has the same key case-insensitively, it will override the existing option.

Parameters:

key - (undocumented)

value - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

option

public DataFrameReader option(String key,
                              double value)

Adds an input option for the underlying data source.

All options are maintained in a case-insensitive way in terms of key names. If a new option has the same key case-insensitively, it will override the existing option.

Parameters:

key - (undocumented)

value - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

options

public DataFrameReader options(scala.collection.Map<String,String> options)

(Scala-specific) Adds input options for the underlying data source.

All options are maintained in a case-insensitive way in terms of key names. If a new option has the same key case-insensitively, it will override the existing option.

You can set the following option(s):

• timeZone (default session local timezone): sets the string that indicates a time zone ID to be used to parse timestamps in the JSON/CSV datasources or partition values. The following formats of timeZone are supported:
  • Region-based zone ID: It should have the form 'area/city', such as 'America/Los_Angeles'.
  • Zone offset: It should be in the format '(+|-)HH:mm', for example '-08:00' or '+01:00'. Also 'UTC' and 'Z' are supported as aliases of '+00:00'.
  Other short names like 'CST' are not recommended to use because they can be ambiguous. If it isn't set, the current value of the SQL config spark.sql.session.timeZone is used by default.

Parameters:

options - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

options

public DataFrameReader options(java.util.Map<String,String> options)

Adds input options for the underlying data source.

All options are maintained in a case-insensitive way in terms of key names. If a new option has the same key case-insensitively, it will override the existing option.

You can set the following option(s):

• timeZone (default session local timezone): sets the string that indicates a time zone ID to be used to parse timestamps in the JSON/CSV datasources or partition values. The following formats of timeZone are supported:
  • Region-based zone ID: It should have the form 'area/city', such as 'America/Los_Angeles'.
  • Zone offset: It should be in the format '(+|-)HH:mm', for example '-08:00' or '+01:00'. Also 'UTC' and 'Z' are supported as aliases of '+00:00'.
  Other short names like 'CST' are not recommended to use because they can be ambiguous. If it isn't set, the current value of the SQL config spark.sql.session.timeZone is used by default.

Parameters:

options - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

orc

public Dataset<Row> orc(String... paths)

Loads ORC files and returns the result as a DataFrame.

You can set the following ORC-specific option(s) for reading ORC files:

• mergeSchema (default is the value specified in spark.sql.orc.mergeSchema): sets whether we should merge schemas collected from all ORC part-files. This will override spark.sql.orc.mergeSchema.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - input paths

Returns:

(undocumented)

Since:

2.0.0

orc

public Dataset<Row> orc(String path)

Loads an ORC file and returns the result as a DataFrame.

Parameters:

path - input path

Returns:

(undocumented)

Since:

1.5.0

orc

public Dataset<Row> orc(scala.collection.Seq<String> paths)

Loads ORC files and returns the result as a DataFrame.

You can set the following ORC-specific option(s) for reading ORC files:

• mergeSchema (default is the value specified in spark.sql.orc.mergeSchema): sets whether we should merge schemas collected from all ORC part-files. This will override spark.sql.orc.mergeSchema.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - input paths

Returns:

(undocumented)

Since:

2.0.0

parquet

public Dataset<Row> parquet(String... paths)

Loads a Parquet file, returning the result as a DataFrame.

You can set the following Parquet-specific option(s) for reading Parquet files:

• mergeSchema (default is the value specified in spark.sql.parquet.mergeSchema): sets whether we should merge schemas collected from all Parquet part-files. This will override spark.sql.parquet.mergeSchema.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

parquet

public Dataset<Row> parquet(String path)

Loads a Parquet file, returning the result as a DataFrame. See the documentation on the other overloaded parquet() method for more details.

Parameters:

path - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

parquet

public Dataset<Row> parquet(scala.collection.Seq<String> paths)

Loads a Parquet file, returning the result as a DataFrame.

You can set the following Parquet-specific option(s) for reading Parquet files:

• mergeSchema (default is the value specified in spark.sql.parquet.mergeSchema): sets whether we should merge schemas collected from all Parquet part-files. This will override spark.sql.parquet.mergeSchema.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

schema

public DataFrameReader schema(StructType schema)

Specifies the input schema. Some data sources (e.g. JSON) can infer the input schema automatically from data. By specifying the schema here, the underlying data source can skip the schema inference step, and thus speed up data loading.

Parameters:

schema - (undocumented)

Returns:

(undocumented)

Since:

1.4.0

schema

public DataFrameReader schema(String schemaString)

Specifies the schema by using the input DDL-formatted string. Some data sources (e.g. JSON) can infer the input schema automatically from data. By specifying the schema here, the underlying data source can skip the schema inference step, and thus speed up data loading.

   spark.read.schema("a INT, b STRING, c DOUBLE").csv("test.csv")
 

Parameters:

schemaString - (undocumented)

Returns:

(undocumented)

Since:

2.3.0

table

public Dataset<Row> table(String tableName)

Returns the specified table/view as a DataFrame. If it's a table, it must support batch reading and the returned DataFrame is the batch scan query plan of this table. If it's a view, the returned DataFrame is simply the query plan of the view, which can either be a batch or streaming query plan.

Parameters:

tableName - is either a qualified or unqualified name that designates a table or view. If a database is specified, it identifies the table/view from the database. Otherwise, it first attempts to find a temporary view with the given name and then match the table/view from the current database. Note that, the global temporary view database is also valid here.

Returns:

(undocumented)

Since:

1.4.0

text

public Dataset<Row> text(String... paths)

Loads text files and returns a DataFrame whose schema starts with a string column named "value", and followed by partitioned columns if there are any. The text files must be encoded as UTF-8.

By default, each line in the text files is a new row in the resulting DataFrame. For example:

   // Scala:
   spark.read.text("/path/to/spark/README.md")

   // Java:
   spark.read().text("/path/to/spark/README.md")
 

You can set the following text-specific option(s) for reading text files:

• wholetext (default false): If true, read a file as a single row and not split by "\n".
• lineSep (default covers all \r, \r\n and \n): defines the line separator that should be used for parsing.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - input paths

Returns:

(undocumented)

Since:

1.6.0

text

public Dataset<Row> text(String path)

Loads text files and returns a DataFrame whose schema starts with a string column named "value", and followed by partitioned columns if there are any. See the documentation on the other overloaded text() method for more details.

Parameters:

path - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

text

public Dataset<Row> text(scala.collection.Seq<String> paths)

Loads text files and returns a DataFrame whose schema starts with a string column named "value", and followed by partitioned columns if there are any. The text files must be encoded as UTF-8.

By default, each line in the text files is a new row in the resulting DataFrame. For example:

   // Scala:
   spark.read.text("/path/to/spark/README.md")

   // Java:
   spark.read().text("/path/to/spark/README.md")
 

You can set the following text-specific option(s) for reading text files:

• wholetext (default false): If true, read a file as a single row and not split by "\n".
• lineSep (default covers all \r, \r\n and \n): defines the line separator that should be used for parsing.
• pathGlobFilter: an optional glob pattern to only include files with paths matching the pattern. The syntax follows org.apache.hadoop.fs.GlobFilter. It does not change the behavior of partition discovery.
• modifiedBefore (batch only): an optional timestamp to only include files with modification times occurring before the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• modifiedAfter (batch only): an optional timestamp to only include files with modification times occurring after the specified Time. The provided timestamp must be in the following form: YYYY-MM-DDTHH:mm:ss (e.g. 2020-06-01T13:00:00)
• recursiveFileLookup: recursively scan a directory for files. Using this option disables partition discovery

Parameters:

paths - input paths

Returns:

(undocumented)

Since:

1.6.0

textFile

public Dataset<String> textFile(String... paths)

Loads text files and returns a Dataset of String. The underlying schema of the Dataset contains a single string column named "value". The text files must be encoded as UTF-8.

If the directory structure of the text files contains partitioning information, those are ignored in the resulting Dataset. To include partitioning information as columns, use text.

By default, each line in the text files is a new row in the resulting DataFrame. For example:

   // Scala:
   spark.read.textFile("/path/to/spark/README.md")

   // Java:
   spark.read().textFile("/path/to/spark/README.md")
 

You can set the text-specific options as specified in DataFrameReader.text.

Parameters:

paths - input path

Returns:

(undocumented)

Since:

2.0.0

textFile

public Dataset<String> textFile(String path)

Loads text files and returns a Dataset of String. See the documentation on the other overloaded textFile() method for more details.

Parameters:

path - (undocumented)

Returns:

(undocumented)

Since:

2.0.0

textFile

public Dataset<String> textFile(scala.collection.Seq<String> paths)

Loads text files and returns a Dataset of String. The underlying schema of the Dataset contains a single string column named "value". The text files must be encoded as UTF-8.

If the directory structure of the text files contains partitioning information, those are ignored in the resulting Dataset. To include partitioning information as columns, use text.

By default, each line in the text files is a new row in the resulting DataFrame. For example:

   // Scala:
   spark.read.textFile("/path/to/spark/README.md")

   // Java:
   spark.read().textFile("/path/to/spark/README.md")
 

You can set the text-specific options as specified in DataFrameReader.text.

Parameters:

paths - input path

Returns:

(undocumented)

Since:

2.0.0