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

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

其他回答

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') 

最简单易懂的解决方案之一是:

IF COL_LENGTH('Table_Name','Column_Name') IS NULL
  BEGIN
    -- Column Not Exists, implement your logic
  END
ELSE
  BEGIN
    -- Column Exists, implement your logic
  END

首先检查dbo.syscolumns(包含字段定义的内部SQL Server表)中是否存在表/列(id/name)组合,如果不存在,则发出适当的ALTER table查询以添加它。例如:

IF NOT EXISTS ( SELECT  *
            FROM    syscolumns
            WHERE   id = OBJECT_ID('Client')
                    AND name = 'Name' ) 
ALTER TABLE Client
ADD Name VARCHAR(64) NULL

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
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