查询数据库

select * from sysobjects  --查询所有信息
SELECT Name FROM Master..SysDatabases ORDER BY Name  --查询所有数据库名字
SELECT name FROM sysobjects WHERE xtype='U' --查询数据库表(先引用数据库[use])
select * from sys.tables  --查询数据库表名
select * from Dictionary  -- 查询表中数据

select * from sys.columns where object_id=object_id('Dictionary') --查询所有列名的信息

SELECT * FROM sys.extended_properties WHERE major_id = OBJECT_ID ('Dictionary' ) --查询表中列的说明

 select name,system_type_id,user_type_id,max_length from sys.columns where object_id=object_id('BalanDetail') --查询表中字段的信息

select name,replace(system_type_id,'56','十'),replace(user_type_id,'56','十'),max_length from sys.columns where object_id=object_id('BalanDetail') --查询所有替换后的信息

select name,
CASE system_type_id 
WHEN '56' THEN 'int'
WHEN '231' THEN 'nvarchar'
WHEN '104' THEN 'bit'
WHEN '61' THEN 'datetime'
END,
CASE user_type_id  
WHEN '56' THEN 'int'
WHEN '231' THEN 'nvarchar'
WHEN '104' THEN 'bit'
WHEN '61' THEN 'datetime'
END,replace(max_length,'-1','max')
,[precision] from sys.columns where object_id=object_id('xxx') --查询所有列名的信息

--56=int , 231 = nvarchar,104 = bit,61 = datetime , -1 = max
---scale     小数位数
-- precision 有效数字位数
select name,
null,
CASE system_type_id 
WHEN '56' THEN 'int'
WHEN '231' THEN 'nvarchar'
WHEN '104' THEN 'bit'
WHEN '61' THEN 'datetime'
END as 类型,
replace(max_length,'-1','max') as 长度
,[precision],scale,CASE user_type_id  
WHEN '56' THEN 'int'
WHEN '231' THEN 'nvarchar'
WHEN '104' THEN 'bit'
WHEN '61' THEN 'datetime'
END as 类型 from sys.columns where object_id=object_id('BalanDetail') --查询所有列名的信息