检查表中是否存在列

Question

如何使用SQL查询检查表中是否存在列？我正在使用Access 2007。

Answer 1

您可以使用Information_schema次观看次数：

If Not Exists (Select Column_Name
               From INFORMATION_SCHEMA.COLUMNS
               Where Table_Name = 'YourTable'
               And Column_Name = 'YourColumn')
begin

-- Column doesn't exist

end

此外，您可能希望通过包含数据库和/或架构来进一步限制where子句。

If Not Exists (Select Column_Name
               From INFORMATION_SCHEMA.COLUMNS
               Where Table_Name = 'YourTable'
               And Column_Name = 'YourColumn'
               And Table_Catalog = 'YourDatabaseName'
               And Table_Schema = 'YourSchemaName')

begin

-- Column doesn't exist

end

Answer 2

if Exists(select * from sys.columns where Name = N'columnName'  
            and Object_ID = Object_ID(N'tableName'))

begin

    -- Column Exists

end

"REFERENCE"

Answer 3

IF NOT EXISTS (SELECT 1
FROM syscolumns sc
JOIN sysobjects so
ON sc.id = so.id
WHERE so.Name = 'TableName'
AND sc.Name = 'ColumnName')
BEGIN
--- do your stuff
END