这个WHERE子句有什么问题？

Question

这个查询不起作用的原因是什么？如果我只是排除WHERE子句,以下查询将起作用.我需要知道它有什么问题.我知道表中存在$ key的给定值,为什么这不起作用？

$q =   "SELECT * WHERE t1.project=$key
            FROM project_technologies AS t1
            JOIN languages AS t2
            ON t1.language = t2.key";

表格包含以下字段:

project_technologies
- 关键
- 项目
- 语言

语言
- 键
- 名称

Answer 1

SELECT * FROM project_technologies AS t1
JOIN languages AS t2
  ON t1.language = t2.key
WHERE t1.project=$key

的where应在结束(JOIN的后)

Answer 2

FROM/JOIN之后的地方.

SELECT    * 
FROM      project_technologies AS t1
JOIN      languages AS t2
ON        t1.language = t2.key
WHERE     t1.project=$key

Answer 3

SELECT *
            FROM project_technologies AS t1
            JOIN languages AS t2
            ON t1.language = t2.key
            WHERE t1.project=$key