pg_num_fields
As mentioned, if you are performing an INSERT/UPDATE or DELETE query and want to know the # of rows affected, you should use pg_affected_rows() instead of pg_num_rows().
However, you can also exploit postgres's RETURNING clause in your query to auto-select columns from the affected rows. This has the advantage of being able to tell not only how many rows a query affects, but exactly which rows those were, especially if you return a primary-key column.
For example:
<?php
// Example query. Let's say that this updates five rows in the source table.
$res = pg_query("Update foo set bar = 'new data' where foo.bar = 'old data' ");
pg_num_rows($res); // 0
pg_affected_rows($res); // 5
pg_fetch_all($res); // FALSE
// Same query, with a RETURNING clause.
$res = pg_query("Update foo set bar = 'new data' where foo.bar = 'old data' RETURNING foo.pkey");
pg_num_rows($res); // 5
pg_affected_rows($res); // 5
pg_fetch_all($res); // Multidimensional array corresponding to our affected rows & returned columns
?>
pg_num_rows
(PHP 4 >= 4.2.0, PHP 5)
pg_num_rows — 行数を返す
説明
int pg_num_rows
( resource $result
)
pg_num_rows() は、PostgreSQL の結果リソースの 行数を返します。
注意:
この関数は、以前は pg_numrows() と呼ばれていました。
返り値
結果の行数を返します。エラー時には -1 を返します。
例
例1 pg_num_rows() の例
<?php
$result = pg_query($conn, "SELECT 1");
$rows = pg_num_rows($result);
echo $rows . " row(s) returned.\n";
?>
上の例の出力は以下となります。
1 row(s) returned.
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User Contributed Notes
pg_num_rows
strata_ranger at hotmail dot com
10-May-2009 07:06
ElDiablo
06-Oct-2008 04:09
About preceding note, you shouldn't use pg_num_rows() for this.
You should have instead a look at pg_affected_rows().
francisco at natserv dot com
07-Jan-2008 05:26
Not sure why this documentation doesn't have the following note:
Note: Use pg_affected_rows() to get number of rows affected by INSERT, UPDATE and DELETE query.
Found on other resources. Adding here in case someone else is looking for the info.