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DELETE

ORDER BY
PLAN
ROWS

Available in: DSQL, ESQL, PSQL

Description: Deletes rows from a database table (or from one or more tables underlying a view), depending on the WHERE and ROWS clauses.

Syntax: 

DELETE
   [TRANSACTION name]
   FROM {tablename | viewname} [alias]
   [WHERE {search-conditions | CURRENT OF cursorname}]
   [PLAN plan_items]
   [ORDER BY sort_items]
   [ROWS <m> [TO <n>]]

<m>, <n>  ::=  Any expression evaluating to an integer.

Restrictions

  • The TRANSACTION directive is only available in ESQL.

  • WHERE CURRENT OF is only available in ESQL and PSQL.

  • The PLAN, ORDER BY and ROWS clauses are not available in ESQL.

ORDER BY

Available in: DSQL, PSQL

Added in: 2.0

Description: DELETE now allows an ORDER BY clause. This only makes sense in combination with ROWS, but is also valid without it.

PLAN

Available in: DSQL, PSQL

Added in: 2.0

Description: DELETE now allows a PLAN clause, so users can optimize the operation manually.

ROWS

Available in: DSQL, PSQL

Added in: 2.0

Description: Limits the amount of rows deleted to a specified number or range.

Syntax: 

ROWS <m> [TO <n>]

<m>, <n>  ::=  Any expression evaluating to an integer.

With a single argument m, the deletion is limited to the first m rows of the dataset defined by the table or view and the optional WHERE and ORDER BY clauses.

Points to note:

  • If m > the total number of rows in the dataset, the entire set is deleted.

  • If m = 0, no rows are deleted.

  • If m < 0, an error is raised.

With two arguments m and n, the deletion is limited to rows m to n inclusively. Row numbers are 1-based.

Points to note when using two arguments:

  • If m > the total number of rows in the dataset, no rows are deleted.

  • If m lies within the set but n doesn't, the rows from m to the end of the set are deleted.

  • If m < 1 or n < 1, an error is raised.

  • If n = m-1, no rows are deleted.

  • If n < m-1, an error is raised.

ROWS can also be used with the SELECT and UPDATE statements.

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Firebird Documentation IndexFirebird 2.0 Language Ref. UpdateDML statements → DELETE