Php/docs/function.pg-query
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)