MySQL SELECT语法错误，我无法识别

Question

我在mysql中尝试一个简单的查询，我收到一个语法错误，需要帮助理解。

SELECT 
    eea.*,
    ee.description,
    eect.title,
    eect.file,
    eect.location,
    eect.img_location
FROM 
    `e_exam` ee,
    `e_exam_attempt` eea,
    `e_exam_cert_template` eect
WHERE 
    eea.a_user_id = 1,
    eea.ee_id = ee.id,
    ee.eect_id = eect.id;

我收到以下错误：

基本上是第13行的语法错误

eea.ee_id = ee.id, ee.eect_id = eect.id LIMIT 0, 25

任何人都知道如何编辑这个以获得-1票改善？

Answer 1

它是一个简单的语法错误，您的WHERE子句不应该用逗号分隔。使用AND或OR等

SELECT 
    eea.*, ee.description, eect.title, eect.file,
    eect.location,eect.img_location
FROM 
    `e_exam` ee,
    `e_exam_attempt` eea,
    `e_exam_cert_template` eect
WHERE 
    eea.a_user_id = 1 AND
    eea.ee_id = ee.id AND
    ee.eect_id = eect.id
LIMIT 0,25

  

您还应该了解JOIN语法

SELECT 
    eea.*, ee.description, eect.title,eect.file,
    eect.location, eect.img_location
FROM `e_exam_attempt` eea
    JOIN `e_exam` ee ON eea.ee_id = ee.id
    JOIN `e_exam_cert_template` eect ON ee.eect_id = eect.id
WHERE 
    eea.a_user_id = 1 
LIMIT 0,25