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CSVReader

Description

Parses CSV-formatted data, returning each row in the CSV file as a separate record. This reader allows for inferring a schema based on the first line of the CSV, if a 'header line' is present, or providing an explicit schema for interpreting the values. See Controller Service's Usage for further documentation.

Tags

comma, csv, delimited, parse, reader, record, row, separated, values

Properties

In the list below required Properties are shown with an asterisk (*). Other properties are considered optional. The table also indicates any default values, and whether a property supports the NiFi Expression Language.

Display NameAPI NameDefault ValueAllowable ValuesDescription
Schema Access Strategy *schema-access-strategyInfer Schema
  • Use 'Schema Name' Property
  • Use 'Schema Text' Property
  • Schema Reference Reader
  • Use String Fields From Header
  • Infer Schema
Specifies how to obtain the schema that is to be used for interpreting the data.
Schema Registryschema-registryController Service:
SchemaRegistry

Implementations:
AmazonGlueSchemaRegistry
ApicurioSchemaRegistry
AvroSchemaRegistry
ConfluentSchemaRegistry
Specifies the Controller Service to use for the Schema Registry

This property is only considered if:
  • the property Schema Access Strategy has a value of schema-reference-reader or schema-name
Schema Nameschema-name${schema.name}Specifies the name of the schema to lookup in the Schema Registry property

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property Schema Access Strategy has a value of schema-name
Schema Versionschema-versionSpecifies the version of the schema to lookup in the Schema Registry. If not specified then the latest version of the schema will be retrieved.

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property Schema Access Strategy has a value of schema-name
Schema Branchschema-branchSpecifies the name of the branch to use when looking up the schema in the Schema Registry property. If the chosen Schema Registry does not support branching, this value will be ignored.

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property Schema Access Strategy has a value of schema-name
Schema Textschema-text${avro.schema}The text of an Avro-formatted Schema

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property Schema Access Strategy has a value of schema-text-property
Schema Reference Reader *schema-reference-readerController Service:
SchemaReferenceReader

Implementations:
ConfluentEncodedSchemaReferenceReader
Service implementation responsible for reading FlowFile attributes or content to determine the Schema Reference Identifier

This property is only considered if:
  • the property Schema Access Strategy has a value of schema-reference-reader
CSV Parser *csv-reader-csv-parserApache Commons CSV
  • Apache Commons CSV
  • Jackson CSV
  • FastCSV
Specifies which parser to use to read CSV records. NOTE: Different parsers may support different subsets of functionality and may also exhibit different levels of performance.
Date FormatDate FormatSpecifies the format to use when reading/writing Date fields. If not specified, Date fields will be assumed to be number of milliseconds since epoch (Midnight, Jan 1, 1970 GMT). If specified, the value must match the Java java.time.format.DateTimeFormatter format (for example, MM/dd/yyyy for a two-digit month, followed by a two-digit day, followed by a four-digit year, all separated by '/' characters, as in 01/01/2017).
Time FormatTime FormatSpecifies the format to use when reading/writing Time fields. If not specified, Time fields will be assumed to be number of milliseconds since epoch (Midnight, Jan 1, 1970 GMT). If specified, the value must match the Java java.time.format.DateTimeFormatter format (for example, HH:mm:ss for a two-digit hour in 24-hour format, followed by a two-digit minute, followed by a two-digit second, all separated by ':' characters, as in 18:04:15).
Timestamp FormatTimestamp FormatSpecifies the format to use when reading/writing Timestamp fields. If not specified, Timestamp fields will be assumed to be number of milliseconds since epoch (Midnight, Jan 1, 1970 GMT). If specified, the value must match the Java java.time.format.DateTimeFormatter format (for example, MM/dd/yyyy HH:mm:ss for a two-digit month, followed by a two-digit day, followed by a four-digit year, all separated by '/' characters; and then followed by a two-digit hour in 24-hour format, followed by a two-digit minute, followed by a two-digit second, all separated by ':' characters, as in 01/01/2017 18:04:15).
CSV Format *CSV FormatCustom Format
  • Custom Format
  • RFC 4180
  • Microsoft Excel
  • Tab-Delimited
  • MySQL Format
  • Informix Unload
  • Informix Unload Escape Disabled
Specifies which "format" the CSV data is in, or specifies if custom formatting should be used.
Value Separator *Value Separator,The character that is used to separate values/fields in a CSV Record. If the property has been specified via Expression Language but the expression gets evaluated to an invalid Value Separator at runtime, then it will be skipped and the default Value Separator will be used.

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property CSV Format has a value of custom
Record Separator *Record Separator\nSpecifies the characters to use in order to separate CSV Records

This property is only considered if:
  • the property CSV Format has a value of custom
Treat First Line as Header *Skip Header Linefalse
  • true
  • false
Specifies whether or not the first line of CSV should be considered a Header or should be considered a record. If the Schema Access Strategy indicates that the columns must be defined in the header, then this property will be ignored, since the header must always be present and won't be processed as a Record. Otherwise, if 'true', then the first line of CSV data will not be processed as a record and if 'false',then the first line will be interpreted as a record.
Ignore CSV Header Column Namesignore-csv-headerfalse
  • true
  • false
If the first line of a CSV is a header, and the configured schema does not match the fields named in the header line, this controls how the Reader will interpret the fields. If this property is true, then the field names mapped to each column are driven only by the configured schema and any fields not in the schema will be ignored. If this property is false, then the field names found in the CSV Header will be used as the names of the fields.
Quote Character *Quote Character"The character that is used to quote values so that escape characters do not have to be used. If the property has been specified via Expression Language but the expression gets evaluated to an invalid Quote Character at runtime, then it will be skipped and the default Quote Character will be used.

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property CSV Format has a value of custom
Escape Character *Escape Character\The character that is used to escape characters that would otherwise have a specific meaning to the CSV Parser. If the property has been specified via Expression Language but the expression gets evaluated to an invalid Escape Character at runtime, then it will be skipped and the default Escape Character will be used. Setting it to an empty string means no escape character should be used.

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property CSV Format has a value of custom
Comment MarkerComment MarkerThe character that is used to denote the start of a comment. Any line that begins with this comment will be ignored.

Supports Expression Language, using FlowFile attributes and Environment variables.

This property is only considered if:
  • the property CSV Format has a value of custom
Null StringNull StringSpecifies a String that, if present as a value in the CSV, should be considered a null field instead of using the literal value.

This property is only considered if:
  • the property CSV Format has a value of custom
Trim Fields *Trim Fieldstrue
  • true
  • false
Whether or not white space should be removed from the beginning and end of fields

This property is only considered if:
  • the property CSV Format has a value of custom
Character Set *csvutils-character-setUTF-8The Character Encoding that is used to encode/decode the CSV file
Allow Duplicate Header Namescsvutils-allow-duplicate-header-namestrue
  • true
  • false
Whether duplicate header names are allowed. Header names are case-sensitive, for example "name" and "Name" are treated as separate fields.
Handling of duplicate header names is CSV Parser specific (where applicable):
* Apache Commons CSV - duplicate headers will result in column data "shifting" right with new fields created for "unknown_field_index_X" where "X" is the CSV column index number
* Jackson CSV - duplicate headers will be de-duplicated with the field value being that of the right-most duplicate CSV column
* FastCSV - duplicate headers will be de-duplicated with the field value being that of the left-most duplicate CSV column

This property is only considered if:
  • the property CSV Format has a value of custom
Trim double quote *Trim double quotetrue
  • true
  • false
Whether or not to trim starting and ending double quotes. For example: with trim string '"test"' would be parsed to 'test', without trim would be parsed to '"test"'.If set to 'false' it means full compliance with RFC-4180. Default value is true, with trim.

This property is only considered if:
  • the property CSV Format has a value of rfc-4180

State Management

This component does not store state.

Restricted

This component is not restricted.

System Resource Considerations

This component does not specify system resource considerations.

See Also