SQL语句笔记

SQL语句

获取连续的日期/时间

1
2
3
4
5
6
declare @Start datetime;
declare @End datetime;
select [Date] =CONVERT(char(4), DATEADD(YEAR, [number], @Start), 121)
from master..spt_values
where type = 'p' and [number] < DATEDIFF(YEAR,@Start,@End) + 1
group by CONVERT(char(4), DATEADD(YEAR, [number], @Start), 121)
1
2
3
4
5
--获取连续的整数值
select top 10 [number]
from master..spt_values
where type='p'
order by [number] asc

注:最多2048行记录

向自增列插入指定数值

1
2
3
4
--表t 字段: [ID]:自增主键 [Name]
SET IDENTITY_INSERT [dbo].[t] ON
insert into [dbo].[t] ([Id],[Name]) values(1,'1')
SET IDENTITY_INSERT [dbo].[t] OFF

注:
1.请及时使用SET IDENTITY_INSERT [dbo].[t] OFF关闭自增列的自定义数值插入
2.每一次连接会话中的任一时刻,只能对一个表设置IDENTITY_INSERT ON,且设置只对当前会话有效
3.插入时一定要列出该标识列

生成数据字典

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
use your-database  --指明数据库  
go

SELECT
表名=case when a.colorder=1 then d.name else '' end,
表说明=case when a.colorder=1 then isnull(f.value,'') else '' end,
字段序号=a.colorder,
字段名=a.name,
标识=case when COLUMNPROPERTY(a.id,a.name,'IsIdentity')=1 then '√'else '' end,
主键=case when exists(SELECT 1 FROM sysobjects where xtype='PK' and name in (SELECT name FROM sysindexes WHERE indid in(SELECT indid FROM sysindexkeys WHERE id = a.id AND colid=a.colid
))) then '√' else '' end,
类型=b.name,
长度=COLUMNPROPERTY(a.id,a.name,'PRECISION'),
占用字节数=a.length,
小数位数=isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0),
允许空=case when a.isnullable=1 then '√'else '' end,
默认值=isnull(e.text,''),
字段说明=isnull(g.[value],'')
FROM syscolumns a
left join systypes b on a.xtype=b.xusertype
inner join sysobjects d on a.id=d.id and d.xtype='U' and d.name<>'dtproperties'
left join syscomments e on a.cdefault=e.id
left join sys.extended_properties g on a.id=g.major_id and a.colid=g.minor_id
left join sys.extended_properties f on d.id=f.major_id and f.minor_id =0
--where d.name='要查询的表' --仅生成指定表的数据字典
order by d.name,a.id,a.colorder