SQL Server 數據庫結構查詢

SELECT (case when a.colorder=1 then d.name else null end) 表名,a.colorder 字段序號,a.name 字段名,

(case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end) 標識,

(case when (SELECT count(*) FROM sysobjects WHERE (name in

(SELECT name FROM sysindexes WHERE (id = a.id) AND (indid in

(SELECT indid FROM sysindexkeys WHERE (id = a.id) AND (colid in

(SELECT colid FROM syscolumns WHERE (id = a.id) AND (name = a.name)))))))

AND (xtype = 'PK'))>0 then '√' else '' end) 主鍵,b.name 類型,a.length 佔用字節數,

COLUMNPROPERTY(a.id,a.name,'PRECISION') as 長度,

isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as 小數位數,(case when a.isnullable=1 then '√'else '' end) 允許空,

isnull(e.text,'') 默認值,isnull(g.[value], ' ') AS [說明]

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.class and f.minor_id=0

where b.name is not null

order by a.id,a.colorder

     公司程序員更新好幾代，但是數據庫結構一直沒變，而最初也沒有規範的生成數據庫字段解釋文檔，僅僅在程序中有註釋。但苦逼測試怎麼可能看到程序呢。一個數據庫中所有表的結構可以用以上的語句查詢，其中說明一欄一般情況下會有該字段的說明。如果是特定查詢某個表的結構，可以將倒數第二行改爲：

                                                                          WHERE d.name='表名'

    另外以下是一些可能會用到的數據庫查詢語句

1、查詢服務器中所有數據庫名稱

SELECT Name FROM Master..SysDatabases ORDER BY Name

2、查詢某個數據庫都有些什麼表

select * from 表名.dbo.sysobjects

where xtype='U'

order by name

其中各個xtype的解釋如下：


AF = Aggregate function (CLR)                                                C = CHECK constraint
D = Default or DEFAULT constraint                                          F = FOREIGN KEY constraint
L = Log                                                                                      FN = Scalar function
FS = Assembly (CLR) scalar-function                                        FT = Assembly (CLR) table-valued function        
IF = In-lined table-function                                                       IT = Internal table
P = Stored procedure                                                               PC = Assembly (CLR) stored-procedure
PK = PRIMARY KEY constraint (type is K)                                 RF = Replication filter stored procedure
S = System table                                                                       SN = Synonym
SQ = Service queue                                                                   TA = Assembly (CLR) DML trigger
TF = Table function                                                                   TR = SQL DML Trigger
TT = Table type                                                                         U = User table
UQ = UNIQUE constraint (type is K)                                         V = View
X = Extended stored procedure

3、查詢某個表的主鍵

SELECT name FROM SysColumns

WHERE id=Object_Id('表名')

and colid=(select top 1 keyno from sysindexkeys where id=Object_Id('表名'))

4、查詢某個表的數據的長度

select sum(Length) as Length_total from SysColumns

where id=Object_Id('表名')