This function cannot be used with any queries that return results. This includes SELECT, OPTIMIZE TABLE, etc.
PDO::exec
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.1.0)
PDO::exec — Execute an SQL statement and return the number of affected rows
Description
PDO::exec() executes an SQL statement in a single function call, returning the number of rows affected by the statement.
PDO::exec() does not return results from a SELECT statement. For a SELECT statement that you only need to issue once during your program, consider issuing PDO::query(). For a statement that you need to issue multiple times, prepare a PDOStatement object with PDO::prepare() and issue the statement with PDOStatement::execute().
Parameters
-
statement -
The SQL statement to prepare and execute.
Data inside the query should be properly escaped.
Return Values
PDO::exec() returns the number of rows that were modified
or deleted by the SQL statement you issued. If no rows were affected,
PDO::exec() returns 0.
Warning
This function may
return Boolean false, but may also return a non-Boolean value which
evaluates to false. Please read the section on Booleans for more
information. Use the ===
operator for testing the return value of this
function.
The following example incorrectly relies on the return value of PDO::exec(), wherein a statement that affected 0 rows results in a call to die():
<?php
$db->exec() or die(print_r($db->errorInfo(), true)); // incorrect
?>Errors/Exceptions
Emits an error with level E_WARNING if the attribute PDO::ATTR_ERRMODE is set
to PDO::ERRMODE_WARNING.
Throws a PDOException if the attribute PDO::ATTR_ERRMODE
is set to PDO::ERRMODE_EXCEPTION.
Examples
Example #1 Issuing a DELETE statement
Count the number of rows deleted by a DELETE statement with no WHERE clause.
<?php
$dbh = new PDO('odbc:sample', 'db2inst1', 'ibmdb2');
/* Delete all rows from the FRUIT table */
$count = $dbh->exec("DELETE FROM fruit");
/* Return number of rows that were deleted */
print "Deleted $count rows.\n";
?>The above example will output:
Deleted 1 rows.
See Also
- PDO::prepare() - Prepares a statement for execution and returns a statement object
- PDO::query() - Prepares and executes an SQL statement without placeholders
- PDOStatement::execute() - Executes a prepared statement
add a note
User Contributed Notes 7 notes
david at acz dot org ¶
18 years ago
soletan at toxa dot de ¶
18 years ago
It's worth noting here, that - in addition to the hints given in docs up there - using prepare, bind and execute provides more benefits than multiply querying a statement: performance and security!
If you insert some binary data (e.g. image file) into database using INSERT INTO ... then it may boost performance of parsing your statement since it is kept small (a few bytes, only, while the image may be several MiBytes) and there is no need to escape/quote the file's binary data to become a proper string value.
And, finally and for example, if you want to get a more secure PHP application which isn't affectable by SQL injection attacks you _have to_ consider using prepare/execute on every statement containing data (like INSERTs or SELECTs with WHERE-clauses). Separating the statement code from related data using prepare, bind and execute is best method - fast and secure! You don't even need to escape/quote/format-check any data.
calin at NOSPAM dot softped dot com ¶
9 years ago
PDO::eval() might return `false` for some statements (e.g. CREATE TABLE) even if the operation completed successfully, when using PDO_DBLIB and FreeTDS. So it is not a reliable way of testing the op status.
PDO::errorInfo() can be used to test the SQLSTATE error code for '00000' (success) and '01000' (success with warning).
<?php
function execute(PDO $conn, $sql) {
$affected = $conn->exec($sql);
if ($affected === false) {
$err = $conn->errorInfo();
if ($err[0] === '00000' || $err[0] === '01000') {
return true;
}
}
return $affected;
}
?>
PDO::errorInfo(): http://php.net/manual/en/pdo.errorinfo.php
List of SQLSTATE Codes: http://www-01.ibm.com/support/knowledgecenter/SSGU8G_11.70.0/com.ibm.sqls.doc/ids_sqs_0809.htm
roberto at spadim dot com dot br ¶
17 years ago
this function don't execute multi_query
to get it see SQLITE_EXEC comments there is an pereg function that get all queries and execute all then an return the last one
Sbastien ¶
2 years ago
Note that with MySQL you can detect a DUPLICATE KEY with INSERT (1 = INSERT, 2 = UPDATE) :
<?php
// MySQL specific INSERT UPDATE-like syntax
$sql = <<<SQL
INSERT INTO customers
SET
id = {$pdo->quote($id)},
name = {$pdo->quote($name)},
address = {$pdo->quote($address)}
AS new
ON DUPLICATE KEY UPDATE
name = new.name,
address = new.address
SQL;
$result = $pdo->exec($sql);
if ($result === 1) {
// An INSERT of a new row has be done
} elseif ($result === 2) {
// An UPDATE of an existing row has be done
}
hungry dot rahly at gmail dot com ¶
14 years ago
For those that want an exec that handles params like prepare/execute does. You can simulate this with another function
<?php
class Real_PDO extends PDO {
public function execParams($sql, $params) {
$stm = $this->prepare($sql);
$result = false;
if( $stm && $stm->execute($params) ) {
$result = $stm->rowCount();
while( $stm->fetch(PDO::FETCH_ASSOC) ) {
}
}
return $result;
}
}
?>
Remember though, if you are doing a lot of inserts, you'll want to do it the manual way, as the prepare statement will speed up when doing multiple executes(inserts). I use this so I can place all my SQL statements in one place, and have auto safe quoting against sql-injections.
If you are wondering about the fetch after, remember some databases can return data SELECT-like data from REMOVE/INSERTS. In the case of PostgreSQL, you can have it return you all records that were actually removed, or have the insert return the records after the insert/post field functions, and io trigger fire, to give you normalized data.
<?php
define("BLAH_INSERT", "INSERT INTO blah (id,data) VALUES(?,?)");
$pdo = new Real_PDO("connect string");
$data = array("1", "2");
$pdo->execParams(BLAH_INSERT, $data);
?>
blah at whatevr dot com ¶
17 years ago
You can't use it not only with SELECT statement, but any statement that might return rows. "OPTIMIZE table" is such example (returns some rows with optimization status).
If you do, PDO will lock-up with the "Cannot execute queries while other unbuffered queries are active." nonsense.
