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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2000-02-21 01:20:41 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2000-02-21 01:20:41 +0000 |
| commit | f72aad5678b5d9bf570a51a9899b4e950ce9f828 (patch) | |
| tree | 86be5d5d4ebcdc4e48a0e50cd41e561b0c09dcf1 | |
| parent | a7f85783fbfa46ab5abefe6bfeae0b8ff35449d8 (diff) | |
| download | postgresql-f72aad5678b5d9bf570a51a9899b4e950ce9f828.tar.gz postgresql-f72aad5678b5d9bf570a51a9899b4e950ce9f828.zip | |
Update discussion of aggregate syntax to mention ALL.
| -rw-r--r-- | doc/src/sgml/syntax.sgml | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml index 08f7955df93..332464429cd 100644 --- a/doc/src/sgml/syntax.sgml +++ b/doc/src/sgml/syntax.sgml @@ -711,6 +711,7 @@ sqrt(emp.salary) <simplelist> <member><replaceable>aggregate_name</replaceable> (<replaceable>expression</replaceable>)</member> + <member><replaceable>aggregate_name</replaceable> (ALL <replaceable>expression</replaceable>)</member> <member><replaceable>aggregate_name</replaceable> (DISTINCT <replaceable>expression</replaceable>)</member> <member><replaceable>aggregate_name</replaceable> ( * )</member> </simplelist> @@ -723,7 +724,8 @@ sqrt(emp.salary) <para> The first form of aggregate expression invokes the aggregate across all input rows for which the given expression yields a non-null value. - The second form invokes the aggregate for all distinct non-null values + The second form is the same as the first, since ALL is the default. + The third form invokes the aggregate for all distinct non-null values of the expression found in the input rows. The last form invokes the aggregate once for each input row regardless of null or non-null values; since no particular input value is specified, it is generally only useful |