带有左连接的 MySQL SELECT 对连接表中的值返回 null
[英]MySQL SELECT with left join returns null on values from joined table
问题描述
Lets say I have two simple tables, programs and seasons :
假设我有两个简单的表、 programs和seasons ：
programs
| id | season_id | title |
| 1 | 1 | Program 1 |
| 2 | 1 | Program 2 |
| 3 | 2 | Program 3 |
seasons
| id | season |
| 1 | Season 1 |
| 2 | Season 2 |
Nothing super fancy really, so now I run the following:真的没有什么超级花哨的，所以现在我运行以下命令：
SELECT
programs.title, seasons.season
FROM
programs
LEFT JOIN seasons ON programs.season_id = seasons.id;
Leaving me with an expected result of:给我留下了预期的结果：
| title | season |
| Program 1 | Season 1 |
| Program 2 | Season 1 |
| Program 3 | Season 2 |
However the actual result is as follows:但实际结果如下：
| title | season |
| Program 1 | NULL |
| Program 2 | NULL |
| Program 3 | NULL |
What is causing this and how to remedy?这是什么原因造成的，如何补救？
1 个解决方案
解决方案1
0 2019-12-11 16:01:19
根据您给出的表结构，它应该是seasons.season 而不是seasons.name
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