(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_num_rows — Returns the number of rows in a result
pg_num_rows() will return the number of rows in an PgSql\Result instance.
Note:
This function used to be called pg_numrows().
resultAn PgSql\Result instance, returned by pg_query() , pg_query_params() or pg_execute() (among others).
The number of rows in the result. On error, -1 is returned.
| Version | Description |
|---|---|
| 8.1.0 |
The result parameter expects an PgSql\Result
instance now; previously, a resource was expected.
|
Example #1 pg_num_rows() example
<?php
$result = pg_query($conn, "SELECT 1");
$rows = pg_num_rows($result);
echo $rows . " row(s) returned.\n";
?>The above example will output:
1 row(s) returned.
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
?>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.