超级有用的SQL语句(分析SQL SERVER 数据库表结构专用)
超级有用的SQL语句 (用于SQL SERVER 服务器)
超级有用的SQL语句 ,执行后返回的列分别是:表名、列名、列类型、列长度、列描述、是否主键,语句如下:
(分析SQL SERVER 数据库表结构专用)
Select Sysobjects.Name As 表名,
Syscolumns.Name As 列名,
Systypes.Name As 列类型,
Syscolumns.Length As 列长度,
Isnull(Sysproperties.Value, Syscolumns.Name) As 列说明,
Case
When Syscolumns.Name In
(Select 主键 = A.Name
from Syscolumns A
Inner Join Sysobjects B On A.Id = B.Id
And B.Xtype = 'U'
And B.Name <> 'Dtproperties'
Where Exists (Select 1
from Sysobjects
Where Xtype = 'Pk'
&
相关文档:
SQL语句优化实践之一SQL_TRACE
环境:在PL/sql上调试数据
Pl/sql developer工具连接实例后即作为一个用户进程占用一个session;
select * from v$session t where t.PROGRAM='plsqldev.exe' and t.USERNAME='DZJC'
查询结果显示了几个关键的字段
SADDR RAW(4) S ......
1
、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断
select
*
from
people
where
peopleId
in
(
select
peopleId
from
people
group
by
peopleId
having
cou ......
1.分页方案一:(利用Not In和SELECT TOP分页)
语句形式:
SELECTTOP10*fromTestTableWHERE(IDNOTIN (SELECTTOP20id fromTestTable ORDERBYid))ORDERBYIDSELECTTOP页大小*fromTestTableWHERE(IDNOTIN (SELECTTOP页大小*页数id from表 ORDERBYid))ORDERBYID
2.分 ......
update t1 set t1.value=t2.value from t2 where t1.id=t2.id
update jbsite_class set topicnum = count
from (select t2.classid,count from (
select distinct classid,count(*) as count
from jbsite_product ......
由于当初表设计的不合理,慢慢的发现浪费许多空间,且对扩展不利。决定不把同类型内容并排列保存,所以今天把多余的列剪掉,补在保留的列下面。
在表名点右键,数据操作,导出SQL脚本数据。照提示操作,这里我喜欢的是可以指定列导出。
然后把不需要的空列删掉,改一下插入的列 ......