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* Functions E-Z * Incorporate changes from #103686 * More functions * More functions * Update docs/reference/esql/functions/floor.asciidoc Co-authored-by: Liam Thompson <32779855+leemthompo@users.noreply.github.com> * Update docs/reference/esql/functions/left.asciidoc Co-authored-by: Liam Thompson <32779855+leemthompo@users.noreply.github.com> * Apply suggestions from code review Co-authored-by: Alexander Spies <alexander.spies@elastic.co> * Review feedback * Fix geo_shape description * Change 'colum'/'field' into 'expressions' * Review feedback * One more --------- Co-authored-by: Liam Thompson <32779855+leemthompo@users.noreply.github.com> Co-authored-by: Alexander Spies <alexander.spies@elastic.co> Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>
66 lines
1.5 KiB
Text
66 lines
1.5 KiB
Text
[discrete]
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[[esql-substring]]
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=== `SUBSTRING`
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*Syntax*
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[.text-center]
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image::esql/functions/signature/substring.svg[Embedded,opts=inline]
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*Parameters*
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`str`::
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String expression. If `null`, the function returns `null`.
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`start`::
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Start position.
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`length`::
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Length of the substring from the start position. Optional; if omitted, all
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positions after `start` are returned.
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*Description*
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Returns a substring of a string, specified by a start position and an optional
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length.
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*Supported types*
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include::types/substring.asciidoc[]
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*Examples*
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This example returns the first three characters of every last name:
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[source.merge.styled,esql]
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----
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include::{esql-specs}/docs.csv-spec[tag=substring]
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----
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[%header.monospaced.styled,format=dsv,separator=|]
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include::{esql-specs}/docs.csv-spec[tag=substring-result]
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|===
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A negative start position is interpreted as being relative to the end of the
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string. This example returns the last three characters of of every last name:
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[source.merge.styled,esql]
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----
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include::{esql-specs}/docs.csv-spec[tag=substringEnd]
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----
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[%header.monospaced.styled,format=dsv,separator=|]
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include::{esql-specs}/docs.csv-spec[tag=substringEnd-result]
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|===
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If length is omitted, substring returns the remainder of the string. This
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example returns all characters except for the first:
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[source.merge.styled,esql]
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----
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include::{esql-specs}/docs.csv-spec[tag=substringRemainder]
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----
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[%header.monospaced.styled,format=dsv,separator=|]
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|===
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include::{esql-specs}/docs.csv-spec[tag=substringRemainder-result]
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|===
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