org.apache.flink.table.descriptors

Class Csv

java.lang.Object

org.apache.flink.table.descriptors.DescriptorBase

org.apache.flink.table.descriptors.FormatDescriptor

org.apache.flink.table.descriptors.Csv

All Implemented Interfaces:

Descriptor

@PublicEvolving
public class Csv
extends FormatDescriptor

Format descriptor for comma-separated values (CSV).

This descriptor aims to comply with RFC-4180 ("Common Format and MIME Type for Comma-Separated Values (CSV) Files") proposed by the Internet Engineering Task Force (IETF).

Note: This descriptor does not describe Flink's old non-standard CSV table source/sink. Currently, this descriptor can be used when writing to Kafka. The old one is still available under "org.apache.flink.table.descriptors.OldCsv" for stream/batch filesystem operations.

Constructor Summary

Constructors

Constructor and Description
Csv() Format descriptor for comma-separated values (CSV).

Method Summary

Modifier and Type	Method and Description
Csv	allowComments() Ignores comment lines that start with '#' (disabled by default).
Csv	arrayElementDelimiter(String delimiter) Sets the array element delimiter string for separating array or row element values (";" by default).
Csv	deriveSchema() Derives the format schema from the table's schema.
Csv	escapeCharacter(char escapeCharacter) Sets the escape character for escaping values (disabled by default).
Csv	fieldDelimiter(char delimiter) Sets the field delimiter character (',' by default).
Csv	ignoreParseErrors() Skip fields and rows with parse errors instead of failing.
Csv	lineDelimiter(String delimiter) Sets the line delimiter ("\n" by default; otherwise "\r" or "\r\n" are allowed).
Csv	nullLiteral(String nullLiteral) Sets the null literal string that is interpreted as a null value (disabled by default).
Csv	quoteCharacter(char quoteCharacter) Sets the quote character for enclosing field values ('"' by default).
Csv	schema(TypeInformation<Row> schemaType) Sets the format schema with field names and the types.
protected Map<String,String>	toFormatProperties() Converts this descriptor into a set of format properties.

Methods inherited from class org.apache.flink.table.descriptors.FormatDescriptor

toProperties

Methods inherited from class org.apache.flink.table.descriptors.DescriptorBase

toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Csv

public Csv()

Format descriptor for comma-separated values (CSV).

This descriptor aims to comply with RFC-4180 ("Common Format and MIME Type for Comma-Separated Values (CSV) Files) proposed by the Internet Engineering Task Force (IETF).

Method Detail

fieldDelimiter

public Csv fieldDelimiter(char delimiter)

Sets the field delimiter character (',' by default).

Parameters:

delimiter - the field delimiter character

lineDelimiter

public Csv lineDelimiter(String delimiter)

Sets the line delimiter ("\n" by default; otherwise "\r" or "\r\n" are allowed).

Parameters:

delimiter - the line delimiter

quoteCharacter

public Csv quoteCharacter(char quoteCharacter)

Sets the quote character for enclosing field values ('"' by default).

Parameters:

quoteCharacter - the quote character

allowComments

public Csv allowComments()

Ignores comment lines that start with '#' (disabled by default). If enabled, make sure to also ignore parse errors to allow empty rows.

ignoreParseErrors

public Csv ignoreParseErrors()

Skip fields and rows with parse errors instead of failing. Fields are set to null in case of errors. By default, an exception is thrown.

arrayElementDelimiter

public Csv arrayElementDelimiter(String delimiter)

Sets the array element delimiter string for separating array or row element values (";" by default).

Parameters:

delimiter - the array element delimiter

escapeCharacter

public Csv escapeCharacter(char escapeCharacter)

Sets the escape character for escaping values (disabled by default).

Parameters:

escapeCharacter - escaping character (e.g. backslash)

nullLiteral

public Csv nullLiteral(String nullLiteral)

Sets the null literal string that is interpreted as a null value (disabled by default).

Parameters:

nullLiteral - null literal (e.g. "null" or "n/a")

schema

public Csv schema(TypeInformation<Row> schemaType)

Sets the format schema with field names and the types. Required if schema is not derived.

Parameters:

schemaType - type information that describes the schema

deriveSchema

public Csv deriveSchema()

Derives the format schema from the table's schema. Required if no format schema is defined.

This allows for defining schema information only once.

The names, types, and fields' order of the format are determined by the table's schema. Time attributes are ignored if their origin is not a field. A "from" definition is interpreted as a field renaming in the format.

toFormatProperties

protected Map<String,String> toFormatProperties()

Description copied from class: FormatDescriptor

Converts this descriptor into a set of format properties. Usually prefixed with FormatDescriptorValidator.FORMAT.

Specified by:

toFormatProperties in class FormatDescriptor