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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2003-10-04 21:05:21 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2003-10-04 21:05:21 +0000 |
| commit | fa09ee60263aa508b20efdc97e36fc725aaf7025 (patch) | |
| tree | 0ebe72793ba9bb4f7434bf15026afe75374ba284 /doc/src | |
| parent | b833c3d4a468975bfea1abc11feee1ca47de84b1 (diff) | |
| download | postgresql-fa09ee60263aa508b20efdc97e36fc725aaf7025.tar.gz postgresql-fa09ee60263aa508b20efdc97e36fc725aaf7025.zip | |
Document the always-true-but-previously-undocumented fact that PQfnumber()
will downcase the supplied field name unless it is double-quoted. Also,
upgrade the routine's handling of double quotes to match the backend,
in particular support doubled double quotes within quoted identifiers.
Per pgsql-interfaces discussion a couple weeks ago.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/libpq.sgml | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index 37e1fffb5fe..3bbad0c4599 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -1,5 +1,5 @@ <!-- -$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.138 2003/10/03 18:26:14 tgl Exp $ +$Header: /cvsroot/pgsql/doc/src/sgml/libpq.sgml,v 1.139 2003/10/04 21:05:20 tgl Exp $ --> <chapter id="libpq"> @@ -1553,8 +1553,7 @@ NULL is returned if the column number is out of range. <term><function>PQfnumber</function><indexterm><primary>PQfnumber</></></term> <listitem> <para> - Returns the column number - associated with the given column name. + Returns the column number associated with the given column name. <synopsis> int PQfnumber(const PGresult *res, const char *column_name); @@ -1564,6 +1563,24 @@ int PQfnumber(const PGresult *res, <para> -1 is returned if the given name does not match any column. </para> + +<para> + The given name is treated like an identifier in an SQL command, + that is, it is downcased unless double-quoted. For example, + given a query result generated from the SQL command +<programlisting> +select 1 as FOO, 2 as "BAR"; +</programlisting> + we would have the results: +<programlisting> +PQfname(res, 0) <lineannotation>foo</lineannotation> +PQfname(res, 1) <lineannotation>BAR</lineannotation> +PQfnumber(res, "FOO") <lineannotation>0</lineannotation> +PQfnumber(res, "foo") <lineannotation>0</lineannotation> +PQfnumber(res, "BAR") <lineannotation>-1</lineannotation> +PQfnumber(res, "\"BAR\"") <lineannotation>1</lineannotation> +</programlisting> +</para> </listitem> </varlistentry> |