$query = mysql_query("SELECT * FROM chapter LEFT JOIN page ON chapter.chapterID=page.chapterID WHERE page.category AND chapter.category LIKE 'Novice' GROUP BY page.pageID,page.chapterID ")or die('Query failed');

我有以下查询,但我还想添加以下WHERE chapter.lectureID=1
我该怎么做。我试过这个:
$query = mysql_query("SELECT * FROM chapter LEFT JOIN page ON chapter.chapterID=page.chapterID WHERE chapter.lectureID=1,page.category AND chapter.category LIKE 'Novice' GROUP BY page.pageID,page.chapterID ")or die('Query failed');

但查询失败。
答案 0 :(得分:1)
从,page.category
子句中删除WHERE
。没有理由去那里,因为它没有被比作价值。
$query = mysql_query("
SELECT * FROM chapter
LEFT JOIN page ON chapter.chapterID=page.chapterID
WHERE chapter.lectureID = 1
AND chapter.category LIKE 'Novice'
GROUP BY page.pageID,page.chapterID
")or die('Query failed');
此外,您正在使用LIKE
运算符,并且您传递的是字符串,而不是模式。您可以将'Novice'
更改为'%Novice%'
,这将匹配包含该字符串的任何内容。