写SQL语句的经验

1。注意用SQL分析器可以看select出来的东西
select right(convert(varchar(30),getdate(),126),3)/2 可以用select将结果集显示出来
2。注意看索引和搜索来找函数

3.碰到表看不明白，可以综合下存储过程看看里面的关系
最近一个月的每天增加用户数
SELECT CONVERT(varchar(20), CustomerregisterTime, 112) as ss,
    COUNT(ss) AS Expr2
FROM CustomerLibTbl
WHERE (CustomerregisterTime >= '2007-5-25')
GROUP BY ss
开始做错了，错误的查询语句是下面的
SELECT CONVERT(varchar(20), CustomerregisterTime, 112) AS Expr1,
    COUNT(CustomerregisterTime) AS Expr2
FROM CustomerLibTbl
WHERE (CustomerregisterTime >= '2007-5-25') AND (CustomerregisterTime <= '2007-6-26')
GROUP BY CustomerregisterTime