Firebird 2.1 Language Reference Update

DML statements
Description: Limits the amount of rows updated to a specified number or range.
Syntax:
ROWS [TO ]
, ::= Any expression evaluating to an integer.
With a single argument m, the update 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 updated.
• If m = 0, no rows are updated.
• If m < 0, an error is raised.
With two arguments m and n, the update 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 updated.
• If m lies within the set but n doesn't, the rows from m to the end of the set are updated.
• If m < 1 or n < 1, an error is raised.
• If n = m-1, no rows are updated.
• If n < m-1, an error is raised.
ROWS can also be used with the SELECT and DELETE statements.
Available in: DSQL, PSQL
Added in: 2.1
UPDATE OR INSERT
Description: UPDATE OR INSERT checks if any existing records already contain the new values supplied for
the MATCHING columns. If so, those records are updated. If not, a new record is inserted. In the absence of a
MATCHING clause, matching is done against the primary key. If a RETURNING clause is present and more than
one matching record is found, an error is raised.
Syntax:
UPDATE OR INSERT INTO
{tablename | viewname} [()]
VALUES ()
[MATCHING ()]
[RETURNING [INTO ]]
::= colname [, colname ...]
::= value [, value ...]
::= :varname [, :varname ...]
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