mysqli-php-quickstart-php-stored-procedures-1
Stored Procedures
Stored Procedures
Stored Procedures
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 #1 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 #2 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 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 #4 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() && $stmt->next_result());
?>Of course, use of the bind API for fetching is
supported as well.
Example #5 Stored Procedures and Prepared Statements
using bind API
<?php
if (!($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()