行列互转
insert into test values(1,'a',1,1000)
insert into test values(1,'a',2,2000)
insert into test values(1,'a',3,4000)
insert into test values(1,'a',4,5000)
insert into test values(2,'b',1,3000)
insert into test values(2,'b',2,3500)
insert into test values(2,'b',3,4200)
insert into test values(2,'b',4,5500)
select * from test
--行转列
select id,name,
[1] as "一季度",
[2] as "二季度",
[3] as "三季度",
[4] as "四季度",
[5] as "5"
from
test
pivot
(
sum(profile)
for quarter in
([1],[2],[3],[4],[5])
)
as pvt
create table test2(id int,name varchar(20), Q1 int, Q2 int, Q3 int, Q4 int)
insert into test2 values(1,'a',1000,2000,4000,5000)
insert into test2 values(2,'b',3000,3500,4200,5500)
select * from test2
--列转行
select id,name,quarter,profile
from
test2
unpivot
(
profile
for quarter in
([Q1],[Q2],[Q3],[Q4])
)
as unpvt
sql替换字符串 substring replace
update tbPersonalInfo set TrueName = replace(TrueName,substring(TrueName,2,4),'**') where ID = 1
--例子2:
update tbPersonalInfo set Mobile = replace(Mobile,substring(Mobile,4,11),'********') where ID = 1
--例子3:
update tbPersonalInfo set Email = replace(Email,'chinamobile','******') where ID = 1
SQL查询一个表内相同纪录 having
select ID from 表 group by ID having sum(1)>1))
(select ID1+ID2+ID3 from 表 group by ID1,ID2,ID3 having sum(1)>1))
SELECT *FROM zy_bho a WHERE EXISTS
(SELECT 1 FROM zy_bho WHERE [PK] <> a.[PK] AND ZYH = a.ZYH)
--方法2:
select a.* from zy_bho a join zy_bho b
on (a.[pk]<>b.[pk] and a.zyh=b.zyh)
--方法3:
select * from zy_bbo where zyh in
(select zyh from zy_bbo group by zyh having count(zyh)>1)
--其中pk是主键或是 unique的字段。
把多行SQL数据变成一条多列数据,即新增列
DeptName=O.OUName,
'9G'=Sum(Case When PersonalGrade=9 Then 1 Else 0 End),
'8G'=Sum(Case When PersonalGrade=8 Then 1 Else 0 End),
'7G4'=Sum(Case When PersonalGrade=7 AND JobGrade =4 Then 1 Else 0 End),
'7G3'=Sum(Case When PersonalGrade=7 AND JobGrade =3 Then 1 Else 0 End),
'6G'=Sum(Case When PersonalGrade=6 Then 1 Else 0 End),
'5G3'=Sum(Case When PersonalGrade=5 AND JobGrade =3 Then 1 Else 0 End),
'5G2'=Sum(Case When PersonalGrade=5 AND JobGrade =2 Then 1 Else 0 End),
'4G'=Sum(Case When PersonalGrade=4 Then 1 Else 0 End),
'3G2'=Sum(Case When PersonalGrade=3 AND JobGrade =2 Then 1 Else 0 End),
'3G1'=Sum(Case When PersonalGrade=3 AND JobGrade =1 Then 1 Else 0 End),
'2G'=Sum(Case When PersonalGrade=2 Then 1 Else 0 End),
'1G'=Sum(Case When PersonalGrade=1 Then 1 Else 0 End),
--' 未定级'=Sum(Case When PersonalGrade=NULL Then 1 Else 0 End)
表复制
SELECT [IMSI]
,count([IMEI]) as num
FROM [Test].[dbo].[PhoneChange] group by [IMSI] order by num desc
语法1:Insert INTO table(field1,field2,...) values(value1,value2,...)
语法2:Insert into Table2(field1,field2,...) select value1,value2,... from Table1(要求目标表Table2必须存在,由于目标表Table2已经存在,所以我们除了插入源表Table1的字段外,还可以插入常量。)
语法3:SELECT vale1, value2 into Table2 from Table1(要求目标表Table2不存在,因为在插入时会自动创建表Table2,并将Table1中指定字段数据复制到Table2中。)
语法4:使用导入导出功能进行全表复制。如果是使用【编写查询以指定要传输的数据】,那么在大数据表的复制就会有问题?因为复制到一定程度就不再动了,内存爆了?它也没有写入到表中。而使用上面3种语法直接执行是会马上刷新到数据库表中的,你刷新一下mdf文件就知道了。
利用带关联子查询Update语句更新数据
Update Table1 set c = (select c from Table2 where a = Table1.a) where c is null
--方法2:
update A
set newqiantity=B.qiantity
from A,B
where A.bnum=B.bnum
--方法3:
update
(select A.bnum ,A.newqiantity,B.qiantity from A left join B on A.bnum=B.bnum) AS C
set C.newqiantity = C.qiantity
where C.bnum =XX
连接远程服务器
select * from openrowset('SQLOLEDB','server=192.168.0.67;uid=sa;pwd=password','SELECT * FROM BCM2.dbo.tbAppl')
--方法2:
select * from openrowset('SQLOLEDB','192.168.0.67';'sa';'password','SELECT * FROM BCM2.dbo.tbAppl')
TRUNCATE TABLE [Table Name]
下面是对Truncate语句在MSSQLServer2000中用法和原理的说明:
Truncate是SQL中的一个删除数据表内容的语句,用法是:
Truncate table 表名 速度快,而且效率高,因为:
TRUNCATE TABLE 在功能上与不带 WHERE 子句的 DELETE 语句相同:二者均删除表中的全部行。但 TRUNCATE TABLE 比 DELETE 速度快,且使用的系统和事务日志资源少。
DELETE 语句每次删除一行,并在事务日志中为所删除的每行记录一项。TRUNCATE TABLE 通过释放存储表数据所用的数据页来删除数据,并且只在事务日志中记录页的释放。
TRUNCATE TABLE 删除表中的所有行,但表结构及其列、约束、索引等保持不变。新行标识所用的计数值重置为该列的种子。如果想保留标识计数值,请改用 DELETE。如果要删除表定义及其数据,请使用 DROP TABLE 语句。
对于由 FOREIGN KEY 约束引用的表,不能使用 TRUNCATE TABLE,而应使用不带 WHERE 子句的 DELETE 语句。由于 TRUNCATE TABLE 不记录在日志中,所以它不能激活触发器。
TRUNCATE TABLE 不能用于参与了索引视图的表。
参考文献
SELECT INTO 和 INSERT INTO SELECT 两种表复制语句
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