添加常量字符串字段时SQL失败

Question

当我将一个常量字符串添加为字段时，我收到一条错误消息

这是错误消息：

我想在SQL视图中将表名添加为我的行的列，我收到一条错误消息：

执行的SQL语句：

[...]

错误来源：.Net SQL客户端数据提供程序

错误消息：使用UNION，INTERSECT或EXCEPT运算符组合的所有查询必须具有相同数量的表达式及其目标列表。

SELECT        Location, ClientID, Type_C, Todays_Date, '1100_vAC' as S_Table

FROM            dbo.1100_vAC

UNION ALL

SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp, '1100_vAD' as S_Table
FROM            dbo.1100_vAD
UNION ALL
SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp,  '1101_AC' as S_Table
FROM            dbo.1101_AC
UNION ALL
SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp, '1101_AA' as S_Table
FROM            dbo.1101_AA
UNION ALL
SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp, '1102_AC' as S_Table
FROM            dbo.1102_AC;

我想看看每一行的源表。

Answer 1

您应该更正您的代码（删除重复的time_stamp）

SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp, '1100_vAC' as S_Table

FROM            dbo.1100_vAC

UNION ALL

SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp,  '1100_vAD' as S_Table
FROM            dbo.1100_vAD
UNION ALL
SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp,  '1101_AC' as S_Table
FROM            dbo.1101_AC
UNION ALL
SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp,  '1101_AA' as S_Table
FROM            dbo.1101_AA
UNION ALL
SELECT        Location, ClientID, Type_C, Todays_Date, Time_Stamp,  '1102_AC' as S_Table
FROM            dbo.1102_AC;

Answer 2

union，intersect和except需要相同数量的列（最好是排序）。如果您在除第一个选项之外的所有选择上复制TIMESTAMP，则会出错。

Answer 3

第一行包含6列，其余包含7列，因为在其余行中添加了两次额外的时间戳列。

Union / union所有联合数据并不是它加入列。因此，您需要保留相同类型的列，以确保整个数据同步且一致