# pg_query

(PHP 4 >= 4.2.0, PHP 5, PHP 7)

pg_query — Execute a query

### Description

pg_query ([ resource `$connection` ], string `$query` ) : resource|false

pg_query() executes the `query` on the specified database `connection`. pg_query_params() should be preferred in most cases.

If an error occurs, and `FALSE` is returned, details of the error can be retrieved using the pg_last_error() function if the connection is valid.

> Note: Although `connection` can be omitted, it is not recommended, since it can be the cause of hard to find bugs in scripts.

> Note:

> This function used to be called pg_exec(). pg_exec() is still available for compatibility reasons, but users are encouraged to use the newer name.

### Parameters

`connection`

  PostgreSQL database connection resource. When `connection` is not present, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().

`query`

  The SQL statement or statements to be executed. When multiple statements are passed to the function, they are automatically executed as one transaction, unless there are explicit BEGIN/COMMIT commands included in the query string. However, using multiple transactions in one function call is not recommended.

  Warning

  String interpolation of user-supplied data is extremely dangerous and is likely to lead to SQL injection vulnerabilities. In most cases pg_query_params() should be preferred, passing user-supplied values as parameters rather than substituting them into the query string.

  Any user-supplied data substituted directly into a query string should be properly escaped.

### Return Values

A query result resource on success or `FALSE` on failure.

### Examples

Example #1 pg_query() example

`<?php
$conn = pg_pconnect("dbname=publisher");
if (!$conn) {
echo "An error occurred.\n";
exit;
}
$result = pg_query($conn, "SELECT author, email FROM authors");
if (!$result) {
echo "An error occurred.\n";
exit;
}
while ($row = pg_fetch_row($result)) {
echo "Author: $row[0] E-mail: $row[1]";
echo "<br />\n";
}
?>`

Example #2 Using pg_query() with multiple statements

`<?php
$conn = pg_pconnect("dbname=publisher");
// these statements will be executed as one transaction
$query = "UPDATE authors SET author=UPPER(author) WHERE id=1;";
$query .= "UPDATE authors SET author=LOWER(author) WHERE id=2;";
$query .= "UPDATE authors SET author=NULL WHERE id=3;";
pg_query($conn, $query);
?>`

### See Also

- pg_connect() - Open a PostgreSQL connection
- pg_pconnect() - Open a persistent PostgreSQL connection
- pg_fetch_array() - Fetch a row as an array
- pg_fetch_object() - Fetch a row as an object
- pg_num_rows() - Returns the number of rows in a result
- pg_affected_rows() - Returns number of affected records (tuples)