Mysql判断表字段或索引是否存在

判断字段是否存在：

drop procedure if exists schema_change; 
delimiter //
create procedure schema_change() begin 
declare currentdatabase varchar();
select database() into currentdatabase;
if not exists (select * from information_schema.columns where table_schema=currentdatabase and table_name = 'rtc_order' and column_name = 'ifupsend') then 
alter table rtc_order
add column `ifupsend` bit not null default comment '是否上传 是否上传';
end if; 
end// 
delimiter ; 
call schema_change(); 

判断索引是否存在：

drop procedure if exists schema_change; 
delimiter //
create procedure schema_change() begin 
declare currentdatabase varchar();
select database() into currentdatabase;
if not exists (select * from information_schema.statistics where table_schema=currentdatabase and table_name = 'rtc_phototype' and index_name = 'index_name') then 
alter table `rtc_phototype` add index index_name ( `imgtype` );
end if; 
end// 
delimiter ; 
call schema_change(); 

从这两段可以看出很多东西，具体可以自己试验一下

关于小编给大家介绍的mysql判断表字段或索引是否存在的内容就给大家介绍到这里，希望对大家有所帮助！