调用：
call add_column_if(‘xxx‘,‘xxx‘,‘xxx‘);
mysql 可重复执行添加列
标签：调用 format arch proc class cut xxx ble concat
mysql 可重复执行添加列
50), IN v_column varchar(50),IN v_discription varchar(1000))
begin
declare stmt varchar(2000);
declare v_flag int;
select count(*) into v_flag from information_schema.columns where table_schema = (select DATABASE()) and table_name = v_table and column_name = v_column;
if(v_flag=0)
then
set @sqlstr = concat(‘ALTER TABLE `‘,v_table,‘` ADD COLUMN `‘,v_column,‘` ‘,v_discription);
prepare stmt from @sqlstr;
execute stmt;
end if;
commit;
end ;