sql中where子句中的未知列

Question

SELECT * 
FROM subjects 
INNER JOIN entries ON entries.subject_id= subjects.subject_id 
INNER JOIN students ON entries.student_id=students.student_id 
WHERE subjects.exam_board LIKE ‘OCR’;

當我執行此操作時，where子句中的錯誤未知列“ OCR”

The following is my subject table

INSERT INTO subjects 
(subject_id, subject_name, level_of_entry, exam_board) 
VALUES 
(1, 'chemistry', 'AS', 'OCR'); 
INSERT INTO subjects 
(subject_id, subject_name, level_of_entry, exam_board) 
VALUES 
(2, 'biology', 'GCSE', 'AQA');
INSERT INTO subjects
(subject_id, subject_name, level_of_entry, exam_board) 
VALUES 
(3, 'music', 'GCSE', 'Edexcel'); 

下面是我的學生表

 INSERT INTO students 
 (student_id,first_name,middle_name,last_name,email,password,reg_date) 
 VALUES 
 (NULL, 'Tom', 'Michael', 'ford',  'tom@yahoo.com','tom1234','2003/12/08');
 INSERT INTO students 
 (student_id,first_name, middle_name, last_name, email, password, reg_date)
 VALUES 
 (NULL, 'michael', 'scoffield', 'burrows',  'lincoln@yahoo.com', 'lincoln1234', '2001/12/16');

Answer 1

您必須在like子句中使用由`插入的'（單引號）符號，希望下面的代碼對您有所幫助

SELECT * 
FROM subjects 
INNER JOIN entries ON entries.subject_id= subjects.subject_id 
INNER JOIN students ON entries.student_id=students.student_id 
WHERE subjects.exam_board LIKE 'OCR';

Answer 2

SELECT * 
FROM subjects 
INNER JOIN entries ON entries.subject_id= subjects.subject_id 
INNER JOIN students ON entries.student_id=students.student_id 
WHERE subjects.exam_board LIKE 'OCR';

您使用了錯誤的報價類型。

您可能還想將自己的“喜歡”更新為

WHERE subjects.exam_board LIKE 'OCR%';