检查行集合是否属于SQL中的特定值？

我想检查给定的表是否有特定的列名，如果它有所有列名，我想让它返回true，如果一个列名不存在，我想让它返回false，这是我的查询：

SELECT COLUMN_NAME
FROM db.INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'MyTable'

我想检查查询结果中是否有这些名称：

---

（'UpdateDate'，'CreatedDate'，'UpdatedBy'）

如果您知道此查询的列表计数，则可以帮助您

SELECT COUNT(COLUMN_NAME)
FROM db.INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'MyTable' AND COLUMN_NAME IN ('UpdatedDate', 'CreatedDate', 'UpdatedBy')
GROUP BY COLUMN_NAME HAVING COUNT(COLUMN_NAME) = 3;

---

如果您知道列表的计数，此查询将帮助您

SELECT COUNT(COLUMN_NAME)
FROM db.INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = 'MyTable' AND COLUMN_NAME IN ('UpdatedDate', 'CreatedDate', 'UpdatedBy')
GROUP BY COLUMN_NAME HAVING COUNT(COLUMN_NAME) = 3;

---

创建一个带有列名的表变量，我们需要使用

信息\u schema.columns

检查这些列名。然后在表变量和

信息\u schema.columns

之间进行检查。不知道这有多高效

查询

declare @cols as varchar(max) = 'UpdatedDate,CreatedDate,UpdatedBy';
declare @cols2 as varchar(max) = '(' + char(39);

set @cols2 += replace(@cols, ',', '''),(''') + ''');';

declare @sql as varchar(max) = 'declare @tbl as table([col] varchar(1000));';
set @sql += 'insert into @tbl values' + @cols2;
set @sql += 'declare @tot as int;set @tot = (select count(*) from @tbl);';
set @sql += 'select case when count(*) = @tot 
             then ''true'' else ''false'' end as [status] 
             from @tbl t1 where exists(
               select 1 from information_schema.columns t2 
               where t1.[col] = t2.[column_name] 
               and t2.[table_name] = ''MyTable'');';

exec(@sql);

---

创建一个带有列名的表变量，我们需要使用

信息\u schema.columns

检查这些列名。然后在表变量和

信息\u schema.columns

之间进行检查。不知道这有多高效

查询

declare @cols as varchar(max) = 'UpdatedDate,CreatedDate,UpdatedBy';
declare @cols2 as varchar(max) = '(' + char(39);

set @cols2 += replace(@cols, ',', '''),(''') + ''');';

declare @sql as varchar(max) = 'declare @tbl as table([col] varchar(1000));';
set @sql += 'insert into @tbl values' + @cols2;
set @sql += 'declare @tot as int;set @tot = (select count(*) from @tbl);';
set @sql += 'select case when count(*) = @tot 
             then ''true'' else ''false'' end as [status] 
             from @tbl t1 where exists(
               select 1 from information_schema.columns t2 
               where t1.[col] = t2.[column_name] 
               and t2.[table_name] = ''MyTable'');';

exec(@sql);