else条件我想查天气THW柱的存在与否 IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'tb_consumer' AND COLUMN_NAME='businness_id' > 0) THEN
PRINT 'test'
哪些错误与上面的SQL存在?出现错误为 您的SQL语法错误;检查对应于你的
下面的查询上太多的时间恰好出现0.04秒 SELECT A.*
FROM `TABLE1`
JOIN TABLE2 ON (TABLE1.ID = TABLE2.ID)
WHERE `COL1` ='1'
而下一查询已4秒 SELECT A.* FROM `TABLE1`
JOIN TABLE2 ON (TABLE1.ID = TABLE2.ID)
WHERE `COL1` ='1'