FirebirdSQL logo
 CommentsProcedural SQL (PSQL) Statements 

Mixing ROWS and FIRST/SKIP or OFFSET/FETCH

ROWS syntax cannot be mixed with FIRST/SKIP or OFFSET/FETCH in the same SELECT expression.Using the different syntaxes in different subqueries in the same statement is allowed.

ROWS Syntax in UNION Queries

When ROWS is used in a UNION query, the ROWS directive is applied to the unioned set and must be placed after the last SELECT statement.

If a need arises to limit the subsets returned by one or more SELECT statements inside UNION, there are a couple of options:

  1. Use FIRST/SKIP syntax in these SELECT statements — bearing in mind that an ordering clause (ORDER BY) cannot be applied locally to the discrete queries, but only to the combined output.

  2. Convert the queries to derived tables with their own ROWS clauses.

  3. Use parenthesized query expressions with OFFSET/FETCH