sql代码：select database select all table

---表中的主鍵
select [name],'tablekey'= (select  top 1 COLUMN_NAME   from   INFORMATION_SCHEMA.KEY_COLUMN_USAGE  where   TABLE_NAME   = sysobjects.name) from  sysobjects where type='U'
 
--所有表
select * from  sysobjects where type='U'
--所有表的主鍵  COLUMN_NAME
select  *   from   INFORMATION_SCHEMA.KEY_COLUMN_USAGE
--数据类型
select * from  systypes
--所有列
select * FROM  syscolumns
 
--所有表的數據類型，長度
SELECT d.name TableName,a.name FieldName,b.name TypeName,a.length Length,a.isnullable IS_NULL --INTO #t
FROM  syscolumns  a,  systypes b,sysobjects d
WHERE  a.xtype=b.xusertype  and  a.id=d.id  and  d.xtype='U'
 
---所有表的主鍵
SELECT d.name as 'TableName',a.name as 'FieldName',b.name as 'TypeName',a.length as 'Length',a.isnullable as 'IS_NULL' --INTO #t
FROM  syscolumns  a,  systypes b,sysobjects d ,INFORMATION_SCHEMA.KEY_COLUMN_USAGE c
WHERE  a.xtype=b.xusertype  and  a.id=d.id  and  d.xtype='U' and c.TABLE_NAME   = d.name
and c.COLUMN_NAME=a.name