sql数据表要新增字段，最好这样写脚本

[root@localhost tsmis3003-sp1-base-20120924]# vi update.sql 

use test;

drop procedure if exists 3003_base1_20120924_update_table_file;

DELIMITER ;;

CREATE  PROCEDURE `3003_base1_20120924_update_table_file`()

BEGIN

if not exists(select 1 from information_schema.COLUMNS where TABLE_SCHEMA='test' and table_name='SystemConfig' and COLUMN_NAME='TrafficLigh

tFrequency') then

alter table SystemConfig  add column TrafficLightFrequency  tinyint(3) default 2;

end if;

if not exists(select 1 from information_schema.COLUMNS where TABLE_SCHEMA='test' and table_name='BaseConfig' and COLUMN_NAME='DistOfOverSto

pline') then

alter table BaseConfig add column DistOfOverStopline int(10) default 0;

end if;

IF  EXISTS(SELECT 1 FROM information_schema.COLUMNS WHERE TABLE_SCHEMA='test' AND table_name='VersionInfo' AND COLUMN_NAME='verDB') then

insert into VersionInfo(verTSMIS,verDB) values('TSMISV3.0.0.3','3.0.0.5');

End IF;

END;;

DELIMITER ;

call  3003_base1_20120924_update_table_file();

DROP   PROCEDURE   IF   EXISTS   `test`.`3003_base1_20120924_update_table_file`;

然后写一个升级脚本，只要一句

mysql -u root test<update.sql 

就搞定了，

这样做的好处是可以避免重复升级导致mysql报字段冲突的错误。