YII2框架中查询生成器Query()的使用方法示例

 select(['id', 'name']) ->from('{{%user}}') ->all(); //指定where条件查询 $data2 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where('id=:id', [':id' => '2']) ->all(); //通过one查询单条记录 $data3 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where('id=3') ->one(); //判断记录是否存在 $exists = (new Query())->from('{{%user}}') ->where('name="aaa"') ->exists(); if ($exists) { echo 'name=aaa 存在'; } //定义字段别名 //注意真实的字段名写后面，别名写前面 $data4 = (new Query())->select(['ids' => 'id', 'names' => 'name']) ->from('{{%user}}') ->where('1=1') ->all(); //通过orderby排序，和limit限制条数 $data5 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where('1=1') ->orderBy('id desc') ->limit(3) ->all(); //多个and条件 //参数是数组，一个key对应一个value，默认以and拼接 $data6 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['id' => 3, 'name' => 'aaa']) ->one(); //in条件 $data7 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['id' => [4, 5, 6]]) ->all(); //或者如下方式 $data7_2 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['in', 'id', [4, 5, 6]]) ->all(); //count统计 $count = (new Query())->from('{{%user}}')->count(); echo '总记录数: ', $count; //大于，大于等于，小于，小于等于where条件 $data8 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['>=', 'id', 5]) ->all(); $data9 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['<=', 'id', 3]) ->all(); //like查询 $data10 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['like', 'name', 'dd']) ->all(); //between筛选和group by分组 //查找出age在18到24之间的，并按sex分组 $data11 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['between', 'age', 18, 24]) ->groupBy('sex') ->all(); //having筛选 //按sex分组，然后统计人数大于3的 $data12 = (new Query())->select(['sex', 'cnt' => 'count(*)']) ->from('{{%user}}') ->groupBy('sex') ->having('cnt > 3') ->all(); //or逻辑条件 //查找姓名为aaa或bbb的用户 //之前where数组是以key=>value方式传递的，如果要表达复杂逻辑关系， //数组第一个元素必须声明是什么逻辑，and还是or //第二个元素表示逻辑左边 //第三个元素表示逻辑右边 $data13 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['or', ['name' => 'aaa'], ['name' => 'bbb']]) ->all(); //复杂的where条件 //我这里只是作为演示 //SELECT `id`, `name` FROM `tb_user` WHERE ((`name`='aaa') OR (`name`='bbb')) OR ((`name`='ccc') OR (`name`='ddd')) $data14 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where([ 'or', [ 'or', ['name' => 'aaa'], ['name' => 'bbb'], ], [ 'or', ['name' => 'ccc'], ['name' => 'ddd'], ], ]) ->all(); //and和or嵌套where条件 //SELECT `id`, `name` FROM `tb_user` WHERE (`sex`=1) AND ((`name` LIKE '%aa%') OR (`name` LIKE '%bb%')) $data15 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where([ 'and', ['sex' => 1], [ 'or', ['like', 'name', 'aa'], ['like', 'name', 'bb'], ], ]) ->all(); //有些时候我们需要根据用户传递过来的参数追加where条件 //追加and条件 $query = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where('sex=1'); //追加age大于18的条件 $query->andWhere(['>', 'age', 18]); echo $query->createCommand()->getRawSql(); //追加or条件 $query2 = (new Query())->select(['id', 'name']) ->from('{{%user}}') ->where(['like', 'name', 'aa']); //追加name相似bb的条件 $query2->orWhere(['like', 'name', 'bb']); echo $query2->createCommand()->getRawSql(); //表别名和连接查询 //SELECT `u`.`id`, `u`.`name`, `aa`.`item_name` FROM `tb_user` `u` LEFT JOIN `tb_auth_assignment` `aa` ON aa.user_id = u.id $data16 = (new Query())->select(['u.id', 'u.name', 'aa.item_name']) ->from(['u' => '{{%user}}']) ->leftJoin(['aa' => '{{%auth_assignment}}'], 'aa.user_id = u.id') ->all(); } }