[英]MYSQL LEFT JOIN is not working as expected not showing all rows from left table
我有form_meta
的以下結構
和entry_meta
我正在運行此查詢
SELECT
sequence AS sequence,
meta_label AS label,
results AS results,
entry_id
FROM
`form_meta`
LEFT JOIN
`entry_meta` ON form_meta.id = entry_meta.form_meta_id
WHERE
`form_meta`.`form_id` = 10
AND is_active = 1
但是,結果我得到了 4 行。 我正在尋找 5 行,因為form_meta
有 5 行,最后一行必須為空。
如果使用正確的表別名會發生什么?
SELECT
fm.sequence AS sequence,
fm.meta_label AS label,
em.results AS results,
em.entry_id
FROM form_meta fm
LEFT JOIN entry_meta em ON fm.id = em.form_meta_id
WHERE fm.form_id = 10 AND fm.is_active = 1;
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.