给定以下代码:

DB::table('users')->get();

我想得到上面的数据库查询生成器将生成的原始SQL查询字符串。在本例中,它将是SELECT*FROM用户。

我该怎么做?


当前回答

首先,您需要通过调用以下命令来启用查询日志:

DB::enableQueryLog();

使用DB facade查询后,您可以编写:

dd(DB::getQueryLog());

输出如下:

array:1 [▼
  0 => array:3 [▼
    "query" => "select * from `users` left join `website_user` on `users`.`id` = `website_user`.`user_id` left join `region_user` on `users`.`id` = `region_user`.`user_id` left ▶"
    "bindings" => array:5 [▶]
    "time" => 3.79
  ]
]

其他回答

您可以使用此包获取加载页面时正在执行的所有查询

https://github.com/barryvdh/laravel-debugbar

我创建了一些简单的函数来从一些查询中获取SQL和绑定。

/**
 * getSql
 *
 * Usage:
 * getSql( DB::table("users") )
 * 
 * Get the current SQL and bindings
 * 
 * @param  mixed  $query  Relation / Eloquent Builder / Query Builder
 * @return array          Array with sql and bindings or else false
 */
function getSql($query)
{
    if( $query instanceof Illuminate\Database\Eloquent\Relations\Relation )
    {
        $query = $query->getBaseQuery();
    }

    if( $query instanceof Illuminate\Database\Eloquent\Builder )
    {
        $query = $query->getQuery();
    }

    if( $query instanceof Illuminate\Database\Query\Builder )
    {
        return [ 'query' => $query->toSql(), 'bindings' => $query->getBindings() ];
    }

    return false;
}

/**
 * logQuery
 *
 * Get the SQL from a query in a closure
 *
 * Usage:
 * logQueries(function() {
 *     return User::first()->applications;
 * });
 * 
 * @param  closure $callback              function to call some queries in
 * @return Illuminate\Support\Collection  Collection of queries
 */
function logQueries(closure $callback) 
{
    // check if query logging is enabled
    $logging = DB::logging();

    // Get number of queries
    $numberOfQueries = count(DB::getQueryLog());

    // if logging not enabled, temporarily enable it
    if( !$logging ) DB::enableQueryLog();

    $query = $callback();

    $lastQuery = getSql($query);

    // Get querylog
    $queries = new Illuminate\Support\Collection( DB::getQueryLog() );

    // calculate the number of queries done in callback
    $queryCount = $queries->count() - $numberOfQueries;

    // Get last queries
    $lastQueries = $queries->take(-$queryCount);

    // disable query logging
    if( !$logging ) DB::disableQueryLog();

    // if callback returns a builder object, return the sql and bindings of it
    if( $lastQuery )
    {
        $lastQueries->push($lastQuery);
    }

    return $lastQueries;
}

用法:

getSql( DB::table('users') );
// returns 
// [
//     "sql" => "select * from `users`",
//     "bindings" => [],
// ]

getSql( $project->rooms() );
// returns
// [
//     "sql" => "select * from `rooms` where `rooms`.`project_id` = ? and `rooms`.`project_id` is not null",
//     "bindings" => [ 7 ],
// ]

以下是我使用的解决方案:

DB::listen(function ($sql, $bindings, $time) {
    $bound = preg_replace_callback("/\?/", function($matches) use ($bindings) {
        static $localBindings;
        if (!isset($localBindings)) {
            $localBindings = $bindings;
        }
        $val = array_shift($localBindings);

        switch (gettype($val)) {
            case "boolean":
                $val = ($val === TRUE) ? 1 : 0;  // mysql doesn't support BOOL data types, ints are widely used
                // $val = ($val === TRUE) ? "'t'" : "'f'";   // todo: use this line instead of the above for postgres and others
                break;

            case "NULL":
                $val = "NULL";
                break;

            case "string":
            case "object":
                $val = "'". addslashes($val). "'";   // correct escaping would depend on the RDBMS
                break;
        }
        return $val;
    }, $sql);
    array_map(function($x) { 
        (new \Illuminate\Support\Debug\Dumper)->dump($x); 
    }, [$sql, $bindings, $bound]);
});

请阅读代码中的注释。我知道,它并不完美,但对于我的日常调试来说,它还可以。它试图以或多或少的可靠性构建绑定查询。但是,不要完全信任它,数据库引擎以不同的方式对值进行转义,而这个短函数并没有实现这些值。所以,仔细观察结果。

要查看Laravel执行的查询,请使用Laravel查询日志

DB::enableQueryLog();

$queries = DB::getQueryLog();

在我看来,这将是初学者的最佳方法:

echo "<pre>";
print_r($query->toSql());
print_r($query->getBindings());

这里也描述了这一点。https://stackoverflow.com/a/59207557/9573341