根据另一个表中的值从一个表中选择多个值

Question

I'd like to select all the rows in the plot table where it exists in watchlist . For instance, with the example I've uploaded to SQLFiddle , I should be able to return rows 3 , 5 and 8 in plot with the query, because they exist in watchlist . The problem is, I am not sure how to go about it. Any ideas?

This is what I've done so far:

SELECT id, p_id, area, jobs from plot WHERE code="SA" AND p_id="3";

But only selects one row, but I understand that it would require a subquery of some sort ie replacing WHERE code="SA" AND p_id="3"; with a reference to the watchlist table.

Answer 1

You can use INNER JOIN to check this:

SELECT t1.id
     , t1.p_id
     , t1.area
     , t1.jobs 
FROM plot t1 
JOIN watchlist t2 ON t1.p_id = t2.p_id 

SQLFiddle

Answer 2

Returns ROWS 3, 5, and 8

SELECT *
FROM plot, watchlist
WHERE plot.p_id = watchlist.p_id;

Answer 3

As you can see from the other responses - there are multiple solutions, so I will add a SUBQUERY solution since you mentioned subquery.

SELECT id, p_id, area, jobs 
  FROM plot 
  WHERE p_id in
  (SELECT p_id
      FROM watchlist);

Answer 4

try this it will work :

SELECT t1.* from `plot` t1 JOIN `watchlist` t2 ON t1.`P_ID`=t2.`P_ID`

SQL Fiddle