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| author | Peter Eisentraut | 2001-02-05 19:21:45 +0000 |
|---|---|---|
| committer | Peter Eisentraut | 2001-02-05 19:21:45 +0000 |
| commit | 192ce19d361b1a6ee5a6d7198ddb38780ec0cab8 (patch) | |
| tree | e00c16f326b378dbc99b4b231d36f9001c0045ca /doc/src | |
| parent | e28c095e8d44d9f77903eca22d9c88e9be72f5ef (diff) | |
Document BETWEEN.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index cf4ac7f7ac7..5e10ded5242 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.49 2001/01/21 22:02:01 petere Exp $ --> +<!-- $Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.50 2001/02/05 19:21:45 petere Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -186,6 +186,29 @@ </para> <para> + In addition to the comparison operators, the special + <token>BETWEEN</token> construct is available. +<synopsis> +<replaceable>a</replaceable> BETWEEN <replaceable>x</replaceable> AND <replaceable>y</replaceable> +</synopsis> + is equivalent to +<synopsis> +<replaceable>a</replaceable> >= <replaceable>x</replaceable> AND <replaceable>a</replaceable> <= <replaceable>y</replaceable> +</synopsis> + Similarly, +<synopsis> +<replaceable>a</replaceable> NOT BETWEEN <replaceable>x</replaceable> AND <replaceable>y</replaceable> +</synopsis> + is equivalent to +<synopsis> +<replaceable>a</replaceable> < <replaceable>x</replaceable> OR <replaceable>a</replaceable> > <replaceable>y</replaceable> +</synopsis> + There is no difference between the two respective forms apart from + the <acronym>CPU</acronym> cycles required to rewrite the first one + into the second one internally. + </para> + + <para> To check whether a value is or is not NULL, use the constructs <synopsis> <replaceable>expression</replaceable> IS NULL |