MSSQL 基础操作

原文链接：https://www.cnblogs.com/ysmc/p/16128243.html

刷新本地缓存

Ctrl+Shift+R

查询

select *from [table]

修改

1、普通更新

UPDATE [table] set [字段]=[values]

2、关联表更新

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

删除（数据）

delete [table]

删除（表）

drop [table]

条件查询

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

事务

1 开始事务: begin transaction

2 提交事务：commit transaction

3 回滚事务: rollback transaction

4 结束事务: 提交或回滚事务都将结束事务

/*--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

查询所有表名

select *from sys.tables

查询所有表包含的字段名

select *from sys.tables

查询所有字段说明

select *from sys.extended_properties

根据表查询所含字段说明

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

创建视图

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

数据字典

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