SQL基础：MSSQL基本语法及实例操作语句

Ctrl+Shift+R

select *from [table]

UPDATE [table] set [字段]=[values]

UPDATE A SET A1 = B1, A2 = B2, A3 = B3 FROM A, B WHERE A.ID = B.ID

delete [table]

drop [table]

select *from [table] where [字段]=[values]

/*–开始事务–*/
begin transaction
declare @errorSum int –定义变量，用于累计事务执行过程中的错误
/*–转帐–*/
update bank set currentMoney=currentMoney-800 where customerName=’张三’
set @errorSum=@errorSum+@@error –累计是否有错误
update bank set currentMoney=currentMoney+800 where customerName=’李四’
set @errorSum=@errorSum+@@error –累计是否有错误

print ‘查看转帐事务过程中的余额’
select * from bank

/*–根据是否有错误，确定事务是提交还是回滚–*/
if @errorSum>0
begin
print ‘交易失败，回滚事务.’
rollback transaction
end
else
begin
print ‘交易成功，提交事务，写入硬盘，永久保存！’
/*–提交并且结束事务–*/
commit transaction
end
go

print ‘查看转帐后的余额’
select * from bank
go

select * from sys.tables

select * from sys.columns

select * from sys.extended_properties

SELECT t.[name] AS 表名,c.[name] AS 字段名,cast(ep.[value]
as varchar(100)) AS [字段说明]
FROM sys.tables AS t
INNER JOIN sys.columns AS c
ON t.object_id = c.object_id
LEFT JOIN sys.extended_properties AS ep
ON ep.major_id = c.object_id AND ep.minor_id = c.column_id WHERE ep.class =1
AND t.name=’UTB_GBNT_PROJ_INFO’——–表名

create view ViewName
(字段1，字段2)
as
(
select 字段1, 字段2
from [table]
)

SELECT t.FieldExp 名称,t.ColumnName 代码,

case t.FieldDataType
when ‘bigint’ then t.FieldDataType
when ‘int’ then t.FieldDataType
when ‘datetime’ then t.FieldDataType
when ‘numeric’ then t.FieldDataType
when ‘nvarchar’ then (cast(t.FieldDataType as varchar(100))+'(‘+cast(t.Fieldlength as varchar(100))+’)’)
when ‘decimal’ then (cast(t.FieldDataType as varchar(100))+'(‘+cast(t.Fieldlength as varchar(100))+’,’+cast(t.Scale as varchar(100))+’)’)
end as 数据类型

,t.Fieldlength 长度,t.Scale 精确度

,case t.FieldNullable
when 0 then ‘不为空’
when 1 then ” end as 说明

from (select
colorder=C.column_id,
FieldExp=ISNULL(PFD.[value],N”),
ColumnName=C.name,
FieldDataType=T.name,
Fieldlength=COLUMNPROPERTY(c.object_id ,c.name ,’PRECISION’),
Scale=C.scale,
FieldNullable=C.is_nullable
–FieldDefVal=D.definition
FROM sys.columns C
INNER JOIN sys.objects O
ON C.[object_id]=O.[object_id]
AND (O.type=’U’ or O.type=’V’)
AND O.is_ms_shipped=0
INNER JOIN sys.types T
ON C.user_type_id=T.user_type_id
LEFT JOIN sys.default_constraints D
ON C.[object_id]=D.parent_object_id
AND C.column_id=D.parent_column_id
AND C.default_object_id=D.[object_id]
LEFT JOIN sys.extended_properties PFD
ON PFD.class=1
AND C.[object_id]=PFD.major_id
AND C.column_id=PFD.minor_id
LEFT JOIN sys.extended_properties PTB
ON PTB.class=1
AND PTB.minor_id=0
AND C.[object_id]=PTB.major_id
LEFT JOIN
(
SELECT
IDXC.[object_id],
IDXC.column_id,
Sort=CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,’IsDescending’)
WHEN 1 THEN ‘DESC’ WHEN 0 THEN ‘ASC’ ELSE ” END,
PrimaryKey=CASE WHEN IDX.is_primary_key=1 THEN N’√’ELSE N” END,
IndexName=IDX.Name
FROM sys.indexes IDX
INNER JOIN sys.index_columns IDXC
ON IDX.[object_id]=IDXC.[object_id]
AND IDX.index_id=IDXC.index_id
LEFT JOIN sys.key_constraints KC
ON IDX.[object_id]=KC.[parent_object_id]
AND IDX.index_id=KC.unique_index_id
INNER JOIN
(
SELECT [object_id], Column_id, index_id=MIN(index_id)
FROM sys.index_columns
GROUP BY [object_id], Column_id
) IDXCUQ
ON IDXC.[object_id]=IDXCUQ.[object_id]
AND IDXC.Column_id=IDXCUQ.Column_id
AND IDXC.index_id=IDXCUQ.index_id
) IDX
ON C.[object_id]=IDX.[object_id]
AND C.column_id=IDX.column_id
WHERE O.name=’–tablename–‘)as t ORDER BY colorder,ColumnName

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,
占用字节数=a.length,
长度=COLUMNPROPERTY(a.id,a.name,’PRECISION’),
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’ –如果只查询指定表,加上此条件
order by a.id,a.colorder