pg_num_rows
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_num_rows — 返回结果中行的数量
返回值
结果中行的数量。错误时返回 -1。
更新日志
| 版本 | 说明 |
|---|---|
| 8.1.0 |
现在 result 参数接受 PgSql\Result
实例，之前接受 resource。
|
示例
示例 #1 pg_num_rows() 示例
<?php
$result = pg_query($conn, "SELECT 1");
$rows = pg_num_rows($result);
echo $rows . " row(s) returned.\n";
?>以上示例会输出：
1 row(s) returned.
＋添加备注
用户贡献的备注 3 notes
strata_ranger at hotmail dot com ¶
15 years ago
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
?>
francisco at natserv dot com ¶
17 years ago
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.