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
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?
其他回答
if exists (
select *
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME = '<table_name>'
and COLUMN_NAME = '<column_name>'
) begin
print 'Column you have specified exists'
end else begin
print 'Column does not exist'
end
select distinct object_name(sc.id)
from syscolumns sc,sysobjects so
where sc.name like '%col_name%' and so.type='U'
以下查询可用于检查表中是否存在搜索列。我们可以根据搜索结果做出决定,如下所示。
IF EXISTS (SELECT 'Y' FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = <YourTableName> AND COLUMN_NAME = <YourColumnName>)
BEGIN
SELECT 'Column Already Exists.'
END
ELSE
BEGIN
ALTER TABLE <YourTableName> ADD <YourColumnName> <DataType>[Size]
END
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
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')