使用3个表从一个表中选择数据[关闭]

I have 3 tables temp_cart, product,plan

temp_cart - prod_id
product   - prod_id, plan_id
plan      - plan_id, title

I have temp_cart.prod_id = 40

Please suggest me mysql_query.

SQL query is shown below. Basically you need to join the tables.

select plan.plan_id, plan.title from temp_cart t 
inner join product p on t.prod_id = p.prod_id 
inner join plan on plan.plan_id = p.plan_id 
where t.prod_id = 40

SELECT temp_cart.prod_id, plan.prod_id, product.prod_id FROM product INNER JOIN temp_cart ON temp_cart.prod_id=product.prod_id;

This may help you:-

select product.prod_id, plan.plan_id, plan.title from product  
  inner join  plan on product.plan_id=plan.plan_id 
  inner join temp_cart on temp_cart.prod_id=product.prod_id  
where temp_cart.prod_id=40

If you only want plan from your temp_cart you could do like this:

select * 
from plan 
where plan_id in (
  select plan_id from plan where prod_id in (select prod_id from temp_cart)
)

Try this: It will help you

SELECT p.plan_id,p.title FROM plan as p INNER JOIN product as pr ON
pr.plan_id=p.plan_id INNER JOIN temp_cart as tc ON 
tc.prod_id=pr.prod_id WHERE tc.prod_id=40.