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
Wheat的答案很好,但它假设您在任何模式或数据库中都没有任何相同的表名/列名对。为了确保安全,使用这个。。。
select *
from Information_Schema.Columns
where Table_Catalog = 'DatabaseName'
and Table_Schema = 'SchemaName'
and Table_Name = 'TableName'
and Column_Name = 'ColumnName'
其他回答
接受答案的临时表格版本:
if (exists(select 1
from tempdb.sys.columns
where Name = 'columnName'
and Object_ID = object_id('tempdb..#tableName')))
begin
...
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
Wheat的答案很好,但它假设您在任何模式或数据库中都没有任何相同的表名/列名对。为了确保安全,使用这个。。。
select *
from Information_Schema.Columns
where Table_Catalog = 'DatabaseName'
and Table_Schema = 'SchemaName'
and Table_Name = 'TableName'
and Column_Name = 'ColumnName'
我需要类似于SQL Server 2000的东西,正如Mitch所指出的,这只适用于SQL Server 2005或更高版本。
这就是我最终的工作:
if exists (
select *
from
sysobjects, syscolumns
where
sysobjects.id = syscolumns.id
and sysobjects.name = 'table'
and syscolumns.name = 'column')
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。