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
还有一种变化。。。
SELECT
Count(*) AS existFlag
FROM
sys.columns
WHERE
[name] = N 'ColumnName'
AND [object_id] = OBJECT_ID(N 'TableName')
其他回答
尝试以下操作:
CREATE FUNCTION ColumnExists(@TableName varchar(100), @ColumnName varchar(100))
RETURNS varchar(1) AS
BEGIN
DECLARE @Result varchar(1);
IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.Columns WHERE TABLE_NAME = @TableName AND COLUMN_NAME = @ColumnName)
BEGIN
SET @Result = 'T'
END
ELSE
BEGIN
SET @Result = 'F'
END
RETURN @Result;
END
GO
GRANT EXECUTE ON [ColumnExists] TO [whoever]
GO
然后这样使用:
IF ColumnExists('xxx', 'yyyy') = 'F'
BEGIN
ALTER TABLE xxx
ADD yyyyy varChar(10) NOT NULL
END
GO
它应该可以在SQL Server 2000和SQL Server 2005上运行。我不确定SQL Server 2008,但我不知道为什么不这样做。
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
执行以下查询以检查给定表中是否存在该列:
IF(SELECT COLUMN_NAME from INFORMATION_SCHEMA.COLUMNS where TABLE_NAME = 'TableName' AND COLUMN_NAME = 'ColumnName') IS NOT NULL
PRINT 'Column Exists in the given table';
调整以下内容以满足您的具体要求:
if not exists (select
column_name
from
INFORMATION_SCHEMA.columns
where
table_name = 'MyTable'
and column_name = 'MyColumn')
alter table MyTable add MyColumn int
这应该会奏效——仔细检查代码,找出愚蠢的错误;例如,您是否在应用插入的同一数据库上查询INFORMATION_SCHEMA?在这两个语句中,您的表/列名是否有拼写错误?
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')