prev function for MATCH_RECOGNIZE

Applies to: check marked yes Databricks SQL check marked yes Databricks Runtime 19.0 and above

Important

This feature is in Beta.

Returns a preceding column value relative to the current row in the match. Use this function only in the MEASURES and DEFINE clauses of MATCH_RECOGNIZE.

Syntax

prev ( { colName | rowPatternVar.colName } [, offset ] )

Arguments

  • colName: A column from the table_reference that MATCH_RECOGNIZE operates on.
  • rowPatternVar.colName: A column qualified by a row pattern variable name. Reads the column value from rows mapped to that variable in the current match.
  • offset: An optional integral literal greater than or equal to 0. The offset relative to the current row. The default is 1.

Returns

A value of the type of colName. If the identified row is outside the current partition, returns NULL.

Common error conditions

  • อัปเดตล่าสุดเมื่อ