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mysqli::begin_transaction

mysqli_begin_transaction

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

mysqli::begin_transaction -- mysqli_begin_transactionInicia uma transação

Descrição

Estilo orientado a objetos

public mysqli::begin_transaction(int $flags = 0, ?string $name = null): bool

Estilo procedural:

mysqli_begin_transaction(mysqli $mysql, int $flags = 0, ?string $name = null): bool

Inicia uma transação. Requer o mecanismo InnoDB (é ativado por padrão). Para detalhes adicionais sobre como as transações do MySQL funcionam, consulte » http://dev.mysql.com/doc/mysql/en/commit.html.

Parâmetros

mysql

Somente no estilo procedural: Um objeto mysqli retornado por mysqli_connect() ou mysqli_init()

flags

As flags válidas são:

  • MYSQLI_TRANS_START_READ_ONLY: Inicia a transação como "START TRANSACTION READ ONLY". Requer MySQL 5.6 e superior.

  • MYSQLI_TRANS_START_READ_WRITE: Inicia a transação como "START TRANSACTION READ WRITE". Requer MySQL 5.6 e superior.

  • MYSQLI_TRANS_START_WITH_CONSISTENT_SNAPSHOT: Inicia a transação como "START TRANSACTION WITH CONSISTENT SNAPSHOT".

name

Nome do ponto de salvamento para a transação.

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Registro de Alterações

Versão Descrição
8.0.0 name agora é anulável.

Exemplos

Exemplo #1 mysqli::begin_transaction() exemplo

Estilo orientado a objetos

<?php

/* Diga ao mysqli para lançar uma exceção se ocorrer um erro */
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

$mysqli = new mysqli("localhost", "my_user", "my_password", "world");

/* O mecanismo de tabela deve suportar transações */
$mysqli->query("CREATE TABLE IF NOT EXISTS language (
Code text NOT NULL,
Speakers int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;"
);

/* Inicia transação */
$mysqli->begin_transaction();

try {
/* Insira alguns valores */
$mysqli->query("INSERT INTO language(Code, Speakers) VALUES ('DE', 42000123)");

/* Tente inserir valores inválidos */
$language_code = 'FR';
$native_speakers = 'Unknown';
$stmt = $mysqli->prepare('INSERT INTO language(Code, Speakers) VALUES (?,?)');
$stmt->bind_param('ss', $language_code, $native_speakers);
$stmt->execute();

/* Se o código atingir esse ponto sem erros, confirme os dados no banco de dados */
$mysqli->commit();
} catch (
mysqli_sql_exception $exception) {
$mysqli->rollback();

throw
$exception;
}

Estilo procedural

<?php

/* Diga ao mysqli para lançar uma exceção se ocorrer um erro */
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

$mysqli = mysqli_connect("localhost", "my_user", "my_password", "world");

/* O mecanismo de tabela deve suportar transações */
mysqli_query($mysqli, "CREATE TABLE IF NOT EXISTS language (
Code text NOT NULL,
Speakers int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;"
);

/* Inicia transação */
mysqli_begin_transaction($mysqli);

try {
/* Insira alguns valores */
mysqli_query($mysqli, "INSERT INTO language(Code, Speakers) VALUES ('DE', 42000123)");

/* Tente inserir valores inválidos */
$language_code = 'FR';
$native_speakers = 'Unknown';
$stmt = mysqli_prepare($mysqli, 'INSERT INTO language(Code, Speakers) VALUES (?,?)');
mysqli_stmt_bind_param($stmt, 'ss', $language_code, $native_speakers);
mysqli_stmt_execute($stmt);

/* Se o código atingir esse ponto sem erros, confirme os dados no banco de dados */
mysqli_commit($mysqli);
} catch (
mysqli_sql_exception $exception) {
mysqli_rollback($mysqli);

throw
$exception;
}

Notas

Nota:

Esta função não funciona com tipos de tabelas não transacionais (como MyISAM ou ISAM).

Veja Também

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User Contributed Notes 4 notes

up
8
Ral
5 years ago
If you receive errors like: "This server version doesn't support 'READ WRITE' and 'READ ONLY'. Minimum 5.6.5 is required" with versions of MariaDB that DO support them, this is due to an internal check in mysqli conflicting with a hack in MariaDB to allow replication with oracle mysql.

MariaDB prefixes its server version numbers with "5.5.5-" for example "5.5.5-10.3.7-MariaDB-1:10.3.7+maria~stretch". This is because oracle mysql would interpet the "10" as version 1. Mysql clients aware of MariaDB have been updated to detect and strip this prefix.

However the check for mysqli.begin-transaction sees the 5.5.5 prefix and so fails.

The workaround is to specify a custom version string without the prefix for MariaDB on the command line using the --version option. Then mysqli.begin-transaction functions as expected.
up
2
PHP Guru
3 years ago
MySQL 5.6 introduces READ ONLY mode which applies optimizations to your transactions that can only be applied when it knows in advance that no table modifications will be made and that no locks will be issued.

The default access mode is READ WRITE in all versions up to and including MySQL 5.6. Starting in MySQL 5.7, the appropriate access mode is detected automatically. So if your transaction attempts modifications or table locks, it will automatically use READ WRITE mode, otherwise it will use READ ONLY mode and your transaction will benefit from the optimizations that come from that without having to explicitly declare is as READ ONLY.

Therefore the only time you need to explicitly declare an access mode is when you are using MySQL 5.6 and you are sure that you want READ ONLY mode. Note that any queries that attempt to modify tables or issue locks in READ ONLY mode will fail. Temporary tables can still be modified.

(Moderators. This post should replace the previous post that I made on the subject. Thanks.)
up
0
VasK@hapir
5 years ago
The above answer from Ral worked for us, Thanks a lot. This is how we implemented the proposed workaround for

Warning: mysqli_begin_transaction(): This server version doesn't support 'READ WRITE' and 'READ ONLY'. Minimum 5.6.5 is required

We appended the following line to /etc/my.cnf and restarted MySQL server

version=10.2.19-MariaDB
up
-1
Luc
7 years ago
For PHP<5.5:

mysqli_query($db, "START TRANSACTION");
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