# 视图查询 视图查询可以实现不依赖数据库视图的多表查询，并不需要数据库支持视图，例如： ``` Db::view('User','id,name') ->view('Profile','truename,phone,email','Profile.user_id=User.id') ->view('Score','score','Score.user_id=Profile.id') ->where('score','>',80) ->select(); ``` 生成的SQL语句类似于： ``` SELECT User.id,User.name,Profile.truename,Profile.phone,Profile.email,Score.score FROM think_user User INNER JOIN think_profile Profile ON Profile.user_id=User.id INNER JOIN think_socre Score ON Score.user_id=Profile.id WHERE Score.score > 80 ``` > 注意，视图查询无需调用`table`和`join`方法，并且在调用`where`和`order`方法的时候只需要使用字段名而不需要加表名。 默认使用INNER join查询，如果需要更改，可以使用： ``` Db::view('User','id,name') ->view('Profile','truename,phone,email','Profile.user_id=User.id','LEFT') ->view('Score','score','Score.user_id=Profile.id','RIGHT') ->where('score','>',80) ->select(); ``` 生成的SQL语句类似于： ``` SELECT User.id,User.name,Profile.truename,Profile.phone,Profile.email,Score.score FROM think_user User LEFT JOIN think_profile Profile ON Profile.user_id=User.id RIGHT JOIN think_socre Score ON Score.user_id=Profile.id WHERE Score.score > 80 ``` 可以使用别名： ``` Db::view('User',['id'=>'uid','name'=>'account']) ->view('Profile','truename,phone,email','Profile.user_id=User.id') ->view('Score','score','Score.user_id=Profile.id') ->where('score','>',80) ->select(); ``` 生成的SQL语句变成： ``` SELECT User.id AS uid,User.name AS account,Profile.truename,Profile.phone,Profile.email,Score.score FROM think_user User INNER JOIN think_profile Profile ON Profile.user_id=User.id INNER JOIN think_socre Score ON Score.user_id=Profile.id WHERE Score.score > 80 ``` 可以使用数组的方式定义表名以及别名，例如： ``` Db::view(['think_user'=>'member'],['id'=>'uid','name'=>'account']) ->view('Profile','truename,phone,email','Profile.user_id=member.id') ->view('Score','score','Score.user_id=Profile.id') ->where('score','>',80) ->select(); ``` 生成的SQL语句变成： ``` SELECT member.id AS uid,member.name AS account,Profile.truename,Profile.phone,Profile.email,Score.score FROM think_user member INNER JOIN think_profile Profile ON Profile.user_id=member.id INNER JOIN think_socre Score ON Score.user_id=Profile.id WHERE Score.score > 80 ```