Question

我创建了以下内容，可以使用where子句子句执行查询，但是当我使用以下查询时：

select * 
from teacherSub 
where teacher = "te123";

它会产生错误：

Msg 207，Level 16，State 1，Line 2

完整代码：

USE [SchoolRecord]
GO

/****** Object:  View [dbo].[teacherSub]    Script Date: 3/30/2015 8:32:56 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

ALTER VIEW [dbo].[teacherSub]
AS
  SELECT sbt.teacherID   AS teacher,
         sub.Name        AS SubjectName,
         sub.GroupID     AS groupName,
         sub.Description AS subdescription
  FROM   Subjects sub,
         SubjectTeacher sbt,
         teacherInfo te
  WHERE  sbt.teacherID = te.TeacherID
         AND sbt.SubjectID = sub.subjectID;

如何在上述视图中应用where条款？

Answer 1

使用Single quotes代替double quotes。 Double quotes用于分隔identifiers

select * from teacherSub where teacher='te123'

Answer 2

正如fireblade所解释的那样，你需要使用单引号用于文字字符串

此外，您还需要使用JOIN子句来连接表（良好实践）。

查看定义

ALTER VIEW [dbo].[teacherSub]
AS
  SELECT sbt.teacherID   AS teacher,
         sub.Name        AS SubjectName,
         sub.GroupID     AS groupName,
         sub.Description AS subdescription
  FROM   Subjects sub
  INNER JOIN  SubjectTeacher sbt ON sbt.SubjectID = sub.subjectID
  INNER JOIN  teacherInfo te     ON sbt.teacherID = te.TeacherID;

<强>查询

select * from teacherSub where teacher= 'te123';

Answer 3

查询中的两项改进

不允许双引号
使用'like'关键字

select * from teacherSub where teacher LIKE 'te123'

SQL Server中的消息207，级别16，状态1，行2

3 个答案: