Laravel检查约束是否违反 [英] Laravel check for constraint violation

问题描述

我很好奇，是否有一种方法可以在删除记录或将记录插入数据库时​​检查是否存在约束冲突错误.

I was curious if there is a way we can check if there is a constraint violation error when delete or insert a record into the database.

抛出的异常称为"QueryException"，但这可能是多种错误.如果我们可以检查异常的具体错误，那就太好了.

The exception thrown is called 'QueryException' but this can be a wide range of errors. Would be nice if we can check in the exception what the specific error is.

推荐答案

您正在寻找23000 Error code (Integrity Constraint Violation).如果您查看 QueryException 类，则它从 PDOException ，因此您可以访问$errorInfo变量.

You are looking for the 23000 Error code (Integrity Constraint Violation). If you take a look at QueryException class, it extends from PDOException, so you can access to $errorInfo variable.

要捕获此错误，您可以尝试:

To catch this error, you may try:

try {
  // ...

} catch (\Illuminate\Database\QueryException $e) {
    var_dump($e->errorInfo);
}

// Example output from MySQL
array (size=3)
   0 => string '23000' (length=5)
   1 => int 1452
   2 => string 'Cannot add or update a child row: a foreign key constraint fails (...)'

更具体地说(重复的条目，不为null，添加/更新子行，删除父行...)，这取决于每个DBMS:

To be more specific (Duplicate entry, not null, add/update child row, delete parent row...), it depends on each DBMS:

• PostgreSQL 和 $e->getCode() 直接
• MySQL ， MariaDB 和

• PostgreSQL and SQL server follow the SQL standard's conventions for SQLSTATE code, so you may return the first value from the array $e->errorInfo[0] or call $e->getCode() directly
• MySQL, MariaDB and SQLite do not strictly obey the rules, so you need to return the second value from the array $e->errorInfo[1]

对于laravel，处理错误很容易，只需将此代码添加到"app/start/global.php"文件中(或创建

For laravel, handling errors is easy, just add this code in your "app/start/global.php" file ( or create a service provider):

App::error(function(\Illuminate\Database\QueryException $exception)
{
    $error = $exception->errorInfo;
    // add your business logic
});

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