標籤:有如下一個預存程序CREATE PROCEDURE `p_next_id`(kind_name VARCHAR(30), i_length int,currentSeqNo VARCHAR(3),OUT o_result INT)BEGIN SET @a= NULL; SET @b= NULL; SELECT id INTO @a FROM t_seq WHERE number= currentSeqNo and length= i_length ;
標籤:Firstly, we need to know what contents tables have! select Date,sum(todayConsume) from industry2_consume where 2_department in (‘V1‘,‘V2‘,‘地管‘,‘武管‘,‘地新‘,‘武新‘) and 2_industry=‘高教自考‘ group by Date;select Date,sum(todayConsume) from
標籤: MySQL users FAQ: How do I show/list MySQL users, i.e., the user accounts in a MySQL database?To show/list the users in a MySQL database, first log into your MySQL server as an administrative user using
標籤: MySQL DATE syntax FAQ: How do I set a MySQL DATE field to default to "now", i.e., the current time?Setting the date to "now"Unfortunately you can‘t default a MySQL DATE field to "now", but you can get the "now" behavior with a MySQL
標籤: Summary: How to drop MySQL database tables and recreate them when you have foreign keyrelationships between the tables.This is pretty obscure, but I thought I‘d post it here so I wouldn‘t forget how to do this ... if you ever have a
標籤: MySQL timestamp FAQ: How can I update a MySQL TIMESTAMP field when I issue an update for a MySQL database table?MySQL has some crazy rules about how timestamp fields can be created, but one nice "timestamp
標籤:mysql 索引 hash index 在大資料量MYISAM引擎表進行JOIN的時候,MYSQL只有NEST LOOP方式進行運算,效率非常低。所以,這種時候應該使用HASH索引。由於只有MEMORY和NDB引擎支援HASH索引,所以應該用他們作為緩衝表。例如:CREATE TEMPORARY TABLE T1 ENGINE=MEMORY AS SELECT * FROM TABLEA;