標籤:1.字串大小寫轉化:(1).將tbl_student表的user_name欄位所有小寫字母,替換為大寫: update tbl_student set user_name=UPPER(user_name);(2).將tbl_student表的user_name欄位所有大寫字母,替換成小寫:update tbl_student set
標籤:mysql binlog format_row今天,開發同事在發布一個SQL的時候失敗後,找到我說報告了如下錯誤:ERROR 1197 (HY000) at line 4: Multi-statement transaction required more than ‘max_binlog_cache_size‘ bytes of storage; increase this mysqld variable and try
標籤:Sql語句最佳化和索引1.Innerjoin和左串連,右串連,子查詢A. inner join內串連也叫等值串連是,left/rightjoin是外串連。SELECT A.id,A.name,B.id,B.name FROM A LEFT JOIN B ON A.id =B.id;SELECT A.id,A.name,B.id,B.name FROM A RIGHT JOIN ON B A.id= B.id;SELECT A.id,
標籤:查詢及重複資料刪除記錄的方法1、尋找表中多餘的重複記錄,重複記錄是根據單個欄位(peopleId)來判斷select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) >
標籤:mysql查詢今天,昨天,近7天,近30天,本月,上一月資料的方法分析總結:話說有一文章表article,儲存文章的添加文章的時間是add_time欄位,該欄位為int(5)類型的,現需要查詢今天添加的文章總數並且按照時間從大到小排序,則查詢語句如下: select * from `article` where date_format(from_UNIXTIME(`add_time`),‘%Y-%m-%d‘) = date_format(now(),‘%Y-%m-%d‘);或者:
標籤:介紹經常會在錯誤記錄檔中看到這個報錯,複製官方文檔的解釋。 Aborted_connects If a client is unable even to connect, the server increments the Aborted_connects status variable. Unsuccessful connection attempts can occur for the following
標籤:MySQL 5.7.15 發布了。更新如下:安全事項: The validate_password plugin now supports the capability of rejecting passwords that match the current session user name, either forward or in reverse. To enable control over this capability, the