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
如果列不存在,请执行以下操作:
BEGIN
IF (COL_LENGTH('[dbo].[Table]', 'Column ') IS NULL)
BEGIN
// Do something
END
END;
如果列确实存在,请执行以下操作:
BEGIN
IF (COL_LENGTH('[dbo].[Table]', 'Column ') IS NOT NULL)
BEGIN
// Do something
END
END;
declare @myColumn as nvarchar(128)
set @myColumn = 'myColumn'
if not exists (
select 1
from information_schema.columns columns
where columns.table_catalog = 'myDatabase'
and columns.table_schema = 'mySchema'
and columns.table_name = 'myTable'
and columns.column_name = @myColumn
)
begin
exec('alter table myDatabase.mySchema.myTable add'
+' ['+@myColumn+'] bigint null')
end
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')
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?