This is an example to explain the powerful of the rollback and commit functions.
Let's suppose you want to be sure that all queries have to be executed without errors before writing data on the database.
Here's the code:
<?php
$all_query_ok=true; // our control variable
//we make 4 inserts, the last one generates an error
//if at least one query returns an error we change our control variable
$mysqli->query("INSERT INTO myCity (id) VALUES (100)") ? null : $all_query_ok=false;
$mysqli->query("INSERT INTO myCity (id) VALUES (200)") ? null : $all_query_ok=false;
$mysqli->query("INSERT INTO myCity (id) VALUES (300)") ? null : $all_query_ok=false;
$mysqli->query("INSERT INTO myCity (id) VALUES (100)") ? null : $all_query_ok=false; //duplicated PRIMARY KEY VALUE
//now let's test our control variable
$all_query_ok ? $mysqli->commit() : $mysqli->rollback();
$mysqli->close();
?>
hope to be helpful!
mysqli::commit
mysqli_commit
(PHP 5)
mysqli::commit -- mysqli_commit — Salva a transação atual
Descrição
Estilo orientado a objeto (metodo)
bool mysqli::commit
( void
)
Estilo de procedimento:
Grava a transação atual para a conexão com o banco de dados especificada
pelo parâmetro link.
Parâmetros
-
link -
Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()
Valor Retornado
Retorna TRUE em caso de sucesso ou FALSE em caso de falha.
Exemplos
Exemplo #1 Estilo orientado a objeto
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query("CREATE TABLE Language LIKE CountryLanguage Type=InnoDB");
/* set autocommit to off */
$mysqli->autocommit(FALSE);
/* Insert some values */
$mysqli->query("INSERT INTO Language VALUES ('DEU', 'Bavarian', 'F', 11.2)");
$mysqli->query("INSERT INTO Language VALUES ('DEU', 'Swabian', 'F', 9.4)");
/* commit transaction */
$mysqli->commit();
/* drop table */
$mysqli->query("DROP TABLE Language");
/* close connection */
$mysqli->close();
?>
Exemplo #2 Estilo de procedimento
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "test");
/* check connection */
if (!$link) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* set autocommit to off */
mysqli_autocommit($link, FALSE);
mysqli_query($link, "CREATE TABLE Language LIKE CountryLanguage Type=InnoDB");
/* Insert some values */
mysqli_query($link, "INSERT INTO Language VALUES ('DEU', 'Bavarian', 'F', 11.2)");
mysqli_query($link, "INSERT INTO Language VALUES ('DEU', 'Swabian', 'F', 9.4)");
/* commit transaction */
mysqli_commit($link);
/* close connection */
mysqli_close($link);
?>
Veja Também
- mysqli_autocommit() - Ativa ou desativa o salvar automaticamente as modificações no banco de dados
- mysqli_rollback() - Rolls back current transaction
Lorenzo - webmaster AT 4tour DOT it ¶
4 years ago
Bob Johnson ¶
3 years ago
The compactness of Lorenzo's code is admirable.
However, it is a good idea to also check $mysqli->affected_rows to make sure that the INSERT statement did not fail.
<?php
$result_query = @mysqli_query($query, $connect);
if (($result_query == false) &&
(mysqli_affected_rows($connect) == 0))
{
// verify the query executed completely and verify that it
// had impact on the table
$success = false;
// here also, the developer could choose to add a ROLLBACK
// statement
}
?>
