MySQL 获取物理表的主键字段

 1 /** 2      * 获取主键字段 3      * @param $table 4      * @param $database 5      * @return mixed 6      */ 7     public function get_primary_key($table,$database){ 8         $sql = "SELECT  9             k.column_name10         FROM 11             information_schema.table_constraints t12         JOIN 13             information_schema.key_column_usage k14         USING 15             (constraint_name,table_schema,table_name)16         WHERE 17             t.constraint_type='PRIMARY KEY'18         AND 19             t.table_schema='$database'20         AND 21             t.table_name='$table'";22         return Db::query($sql)[0]["column_name"];    // 数据库查询语句根据情况而定23 24     }