如果不存在,我需要添加一个特定的列。我有类似以下的内容,但它总是返回false:
IF EXISTS(SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'myTableName'
AND COLUMN_NAME = 'myColumnName')
如何检查SQL Server数据库的表中是否存在列?
如果不存在,我需要添加一个特定的列。我有类似以下的内容,但它总是返回false:
IF EXISTS(SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'myTableName'
AND COLUMN_NAME = 'myColumnName')
如何检查SQL Server数据库的表中是否存在列?
当前回答
试试这个
SELECT COLUMNS.*
FROM INFORMATION_SCHEMA.COLUMNS COLUMNS,
INFORMATION_SCHEMA.TABLES TABLES
WHERE COLUMNS.TABLE_NAME = TABLES.TABLE_NAME
AND Upper(COLUMNS.COLUMN_NAME) = Upper('column_name')
其他回答
下面是我用来管理数据库中列添加的简单脚本:
IF NOT EXISTS (
SELECT *
FROM sys.Columns
WHERE Name = N'QbId'
AND Object_Id = Object_Id(N'Driver')
)
BEGIN
ALTER TABLE Driver ADD QbId NVARCHAR(20) NULL
END
ELSE
BEGIN
PRINT 'QbId is already added on Driver'
END
在此示例中,Name是要添加的ColumnName,Object_Id是TableName
我更喜欢INFORMATION_SCHEMA.COLUMNS而不是系统表,因为Microsoft不保证在不同版本之间保留系统表。例如,dbo.syscolumns在SQL Server 2008中仍然有效,但它已被弃用,将来可以随时删除。
这在SQL Server 2000中对我有效:
IF EXISTS
(
SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'table_name'
AND column_name = 'column_name'
)
BEGIN
...
END
试试这个。。。
IF NOT EXISTS(
SELECT TOP 1 1
FROM INFORMATION_SCHEMA.COLUMNS
WHERE
[TABLE_NAME] = 'Employees'
AND [COLUMN_NAME] = 'EmployeeID')
BEGIN
ALTER TABLE [Employees]
ADD [EmployeeID] INT NULL
END
IF EXISTS (
SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_CATALOG = 'Database Name'
and TABLE_SCHEMA = 'Schema Name'
and TABLE_NAME = 'Table Name'
and COLUMN_NAME = 'Column Name'
and DATA_TYPE = 'Column Type') -- Where statement lines can be deleted.
BEGIN
-- Column exists in table
END
ELSE BEGIN
-- Column does not exist in table
END