加入 2 个 mysql 查询，其中第二个查询依赖于第一个的 output

Question

I use my first query to get the id and name of the user like this:

select id,name from temp_card where sex='$sex' and city='$city' order by name ASC

Then I have a second query that uses the results from the first, and gets more data from another table:

select images from temp_card_images where temp_card_id=". $row['id'] ." order by id ASC limit 1

How can I combine these two queries so that I can print out the 3 fields (id, name and images) in a single while loop?

Thank you!

Answer 1

You needs to perform a JOIN query

select tc.id, tc.name, tci.images from temp_card tc
left join temp_card_images  tci
on tc.id = tci.temp_card_id
where tc.sex='$sex' and tc.city='$city' order by tc.name ASC

Answer 2

You need to learn about JOINs. This can be achieved like this

SELECT tc.id,tc.name,tci.images
FROM temp_card tc
    INNER JOIN temp_card_images tci ON tc.id=tci.temp_card_id
WHERE sex='$sex' 
  AND city='$city' 
GROUP BY tc.id
ORDER BY name ASC

Answer 3

Although unrelated, I would highly recommend looking into using PDO as your database access layer. It works with most database types like MySQL, SQLite, etc.. and it will help against SQL injection to your database.