diff options
| author | Andrew Gierth <rhodiumtoad@postgresql.org> | 2018-05-21 17:02:17 +0100 |
|---|---|---|
| committer | Andrew Gierth <rhodiumtoad@postgresql.org> | 2018-05-21 17:32:24 +0100 |
| commit | 3b0fb2529fdfc4632c9d61194ecd6f8551c38309 (patch) | |
| tree | 595a24303d0aae04a5cef5eafaa69eb3eb0b11d0 /doc/src | |
| parent | ced0cdc76cfc09eaa722e79fe9720729703da2ce (diff) | |
Fix SQL:2008 FETCH FIRST syntax to allow parameters.
OFFSET <x> ROWS FETCH FIRST <y> ROWS ONLY syntax is supposed to accept
<simple value specification>, which includes parameters as well as
literals. When this syntax was added all those years ago, it was done
inconsistently, with <x> and <y> being different subsets of the
standard syntax.
Rectify that by making <x> and <y> accept the same thing, and allowing
either a (signed) numeric literal or a c_expr there, which allows for
parameters, variables, and parenthesized arbitrary expressions.
Per bug #15200 from Lukas Eder.
Backpatch all the way, since this has been broken from the start.
Discussion: https://postgr.es/m/877enz476l.fsf@news-spur.riddles.org.uk
Discussion: http://postgr.es/m/152647780335.27204.16895288237122418685@wrigleys.postgresql.org
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/ref/select.sgml | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml index 95f23219746..19a7fe5baa1 100644 --- a/doc/src/sgml/ref/select.sgml +++ b/doc/src/sgml/ref/select.sgml @@ -1319,12 +1319,14 @@ OFFSET <replaceable class="parameter">start</replaceable> OFFSET <replaceable class="parameter">start</replaceable> { ROW | ROWS } FETCH { FIRST | NEXT } [ <replaceable class="parameter">count</replaceable> ] { ROW | ROWS } ONLY </synopsis> - In this syntax, to write anything except a simple integer constant for - <replaceable class="parameter">start</> or <replaceable - class="parameter">count</replaceable>, you must write parentheses - around it. - If <replaceable class="parameter">count</> is - omitted in a <literal>FETCH</> clause, it defaults to 1. + In this syntax, the <replaceable class="parameter">start</replaceable> + or <replaceable class="parameter">count</replaceable> value is required by + the standard to be a literal constant, a parameter, or a variable name; + as a <productname>PostgreSQL</productname> extension, other expressions + are allowed, but will generally need to be enclosed in parentheses to avoid + ambiguity. + If <replaceable class="parameter">count</replaceable> is + omitted in a <literal>FETCH</literal> clause, it defaults to 1. <literal>ROW</literal> and <literal>ROWS</literal> as well as <literal>FIRST</literal> and <literal>NEXT</literal> are noise words that don't influence |