Sql 查询各组最新数据
列有a、b、time，查出以a分组time为最新的b的数据，组内最新子查询，再joinSELECT
t1.a,
t1.b,
t1.time
FROM
your_table t1
INNER JOIN (
SELECT
a,
MAX("time") AS max_time
FROM
...
SqlServer实现数组遍历
思路把数据保存为带分隔符长字符串，如"aaa,bbb,ccc,ddd,..."，利用字符串方法遍历每个元素知识点查询结果拼接成字符串查询字符数组元素个数获取字符数组指定元素sql try...catch事务-- 删除fun
If Exists (Select * from sys.objects where name ='Get_StrArrayLength' and type =N'FN...