MySQL and PHP
Copyright 1997-2021 the PHP Documentation Group.
The MySQL database supports stored procedures. A stored
procedure is a subroutine stored in the database catalog.
Applications can call and execute the stored procedure. The
CALL
SQL statement is used to execute a
stored procedure.
Parameter
Stored procedures can have IN
,
INOUT
and OUT
parameters,
depending on the MySQL version. The mysqli interface has no
special notion for the different kinds of parameters.
IN parameter
Input parameters are provided with the CALL
statement. Please, make sure values are escaped correctly.
Example 3.19 Calling a stored procedure
<?php $mysqli = new mysqli("example.com", "user", "password", "database"); if ($mysqli->connect_errno) { echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error; } if (!$mysqli->query("DROP TABLE IF EXISTS test") || !$mysqli->query("CREATE TABLE test(id INT)")) { echo "Table creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$mysqli->query("DROP PROCEDURE IF EXISTS p") || !$mysqli->query("CREATE PROCEDURE p(IN id_val INT) BEGIN INSERT INTO test(id) VALUES(id_val); END;")) { echo "Stored procedure creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$mysqli->query("CALL p(1)")) { echo "CALL failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!($res = $mysqli->query("SELECT id FROM test"))) { echo "SELECT failed: (" . $mysqli->errno . ") " . $mysqli->error; } var_dump($res->fetch_assoc()); ?>
The above example will output:
array(1) { ["id"]=> string(1) "1" }
INOUT/OUT parameter
The values of INOUT
/OUT
parameters are accessed using session variables.
Example 3.20 Using session variables
<?php $mysqli = new mysqli("example.com", "user", "password", "database"); if ($mysqli->connect_errno) { echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error; } if (!$mysqli->query("DROP PROCEDURE IF EXISTS p") || !$mysqli->query('CREATE PROCEDURE p(OUT msg VARCHAR(50)) BEGIN SELECT "Hi!" INTO msg; END;')) { echo "Stored procedure creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$mysqli->query("SET @msg = ''") || !$mysqli->query("CALL p(@msg)")) { echo "CALL failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!($res = $mysqli->query("SELECT @msg as _p_out"))) { echo "Fetch failed: (" . $mysqli->errno . ") " . $mysqli->error; } $row = $res->fetch_assoc(); echo $row['_p_out']; ?>
The above example will output:
Hi!
Application and framework developers may be able to provide a more convenient API using a mix of session variables and databased catalog inspection. However, please note the possible performance impact of a custom solution based on catalog inspection.
Handling result sets
Stored procedures can return result sets. Result sets returned
from a stored procedure cannot be fetched correctly using
mysqli_query
.
The
mysqli_query
function combines statement execution and fetching the first
result set into a buffered result set, if any. However, there
are additional stored procedure result sets hidden from the user
which cause
mysqli_query
to fail returning the user expected result sets.
Result sets returned from a stored procedure are fetched using
mysqli_real_query
or
mysqli_multi_query
.
Both functions allow fetching any number of result sets returned
by a statement, such as CALL
. Failing to
fetch all result sets returned by a stored procedure causes an
error.
Example 3.21 Fetching results from stored procedures
<?php $mysqli = new mysqli("example.com", "user", "password", "database"); if ($mysqli->connect_errno) { echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error; } if (!$mysqli->query("DROP TABLE IF EXISTS test") || !$mysqli->query("CREATE TABLE test(id INT)") || !$mysqli->query("INSERT INTO test(id) VALUES (1), (2), (3)")) { echo "Table creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$mysqli->query("DROP PROCEDURE IF EXISTS p") || !$mysqli->query('CREATE PROCEDURE p() READS SQL DATA BEGIN SELECT id FROM test; SELECT id + 1 FROM test; END;')) { echo "Stored procedure creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$mysqli->multi_query("CALL p()")) { echo "CALL failed: (" . $mysqli->errno . ") " . $mysqli->error; } do { if ($res = $mysqli->store_result()) { printf("---\n"); var_dump($res->fetch_all()); $res->free(); } else { if ($mysqli->errno) { echo "Store failed: (" . $mysqli->errno . ") " . $mysqli->error; } } } while ($mysqli->more_results() && $mysqli->next_result()); ?>
The above example will output:
--- array(3) { [0]=> array(1) { [0]=> string(1) "1" } [1]=> array(1) { [0]=> string(1) "2" } [2]=> array(1) { [0]=> string(1) "3" } } --- array(3) { [0]=> array(1) { [0]=> string(1) "2" } [1]=> array(1) { [0]=> string(1) "3" } [2]=> array(1) { [0]=> string(1) "4" } }
Use of prepared statements
No special handling is required when using the prepared
statement interface for fetching results from the same stored
procedure as above. The prepared statement and non-prepared
statement interfaces are similar. Please note, that not every
MYSQL server version may support preparing the
CALL
SQL statement.
Example 3.22 Stored Procedures and Prepared Statements
<?php $mysqli = new mysqli("example.com", "user", "password", "database"); if ($mysqli->connect_errno) { echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error; } if (!$mysqli->query("DROP TABLE IF EXISTS test") || !$mysqli->query("CREATE TABLE test(id INT)") || !$mysqli->query("INSERT INTO test(id) VALUES (1), (2), (3)")) { echo "Table creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$mysqli->query("DROP PROCEDURE IF EXISTS p") || !$mysqli->query('CREATE PROCEDURE p() READS SQL DATA BEGIN SELECT id FROM test; SELECT id + 1 FROM test; END;')) { echo "Stored procedure creation failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!($stmt = $mysqli->prepare("CALL p()"))) { echo "Prepare failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$stmt->execute()) { echo "Execute failed: (" . $stmt->errno . ") " . $stmt->error; } do { if ($res = $stmt->get_result()) { printf("---\n"); var_dump(mysqli_fetch_all($res)); mysqli_free_result($res); } else { if ($stmt->errno) { echo "Store failed: (" . $stmt->errno . ") " . $stmt->error; } } } while ($stmt->more_results() && $stmt->next_result()); ?>
Of course, use of the bind API for fetching is supported as well.
Example 3.23 Stored Procedures and Prepared Statements using bind API
<?php if (!($stmt = $mysqli->prepare("CALL p()"))) { echo "Prepare failed: (" . $mysqli->errno . ") " . $mysqli->error; } if (!$stmt->execute()) { echo "Execute failed: (" . $stmt->errno . ") " . $stmt->error; } do { $id_out = NULL; if (!$stmt->bind_result($id_out)) { echo "Bind failed: (" . $stmt->errno . ") " . $stmt->error; } while ($stmt->fetch()) { echo "id = $id_out\n"; } } while ($stmt->more_results() && $stmt->next_result()); ?>
See also
mysqli::query
|
mysqli::multi_query
|
mysqli_result::next-result
|
mysqli_result::more-results
|