基础篇
//查询时间，友好提示 $sql = "select date_format(create_time, '%Y-%m-%d') as day from table_name"; 复制代码 //int 时间戳类型 $sql = "select from_unixtime(create_time, '%Y-%m-%d') as day from table_name"; 复制代码 //一个sql返回多个总数 $sql = "select count(*) all, " ; $sql .= " count(case when status = 1 then status end) status_1_num, "; $sql .= " count(case when status = 2 then status end) status_2_num "; $sql .= " from table_name"; 复制代码 //Update Join / Delete Join $sql = "update table_name_1 "; $sql .= " inner join table_name_2 on table_name_1.id = table_name_2.uid "; $sql .= " inner join table_name_3 on table_name_3.id = table_name_1.tid "; $sql .= " set *** = *** "; $sql .= " where *** "; //delete join 同上。 复制代码 //替换某字段的内容的语句 $sql = "update table_name set content = REPLACE(content, 'aaa', 'bbb') "; $sql .= " where (content like '