SELECT JOIN WHERE一条记录不存在

Question

I have 2 tables

id      name   type
1       aa     driver
2       bb     cyclist
3       cc     runner

parent_id      key      value
1              mobile   00299029
2              mobile   008772
2              active   1
3              mobile   09887
3              active   0

I need to get the record 1,aa,driver, the one that has not a record with value 'active' in the second table. My last try was something like this, but I'n not sure to be even a bit close to what I need, my result is always 0 records

SELECT t1.name as name
FROM table1 as t1
JOIN table2 as t2 ON t1.id = t2.parent_id
AND NOT EXISTS (
  SELECT * FROM table2
   WHERE key = 'active'
)

Answer 1

You can use NOT EXISTS as follows:

select t1.name from table1 t1 
where not exists 
(
    select 1 from table2 t2 where t1.id = t2.parent_id  AND t2.key = 'active'
)

Answer 2

Try this (I think, not entirely sure I understand the linkage):

SELECT t1.name as name
FROM table1 as t1
LEFT JOIN table2 as t2 ON t1.id = t2.parent_id and t2.key = 'active' where t2.key is null

A left join returns all elements of the first table regardless of whether they have a corresponding record in the joined table. By then including t2.key is null in the where clause, you limit it to records that only exist in the first table.

Answer 3

Just a left join would do

    SELECT t1.name as name
     FROM table1 as t1
LEFT JOIN table2 as t2 
       ON t1.id = t2.parent_id
      AND t2.key = 'active'
    WHERE t2.key IS NULL

Answer 4

This will work:

SELECT t1.name as name
FROM table1 as t1
JOIN table2 as t2 ON t1.id = t2.parent_id
AND t2.key  not like '%active%'

Answer 5

I think Your query is not working in this case, please try this

 SELECT name FROM table1 
 JOIN table2 ON table1.id = 
 table2.parent_id where id not IN ( SELECT parent_id 
 FROM 
table2 WHERE `key` = 'active' )

Answer 6

Select id,name,type from table1 
where id Not in
(Select 
 parent_id from table2 
 group by parent_id 
 having key= 
 'active') 

Better avoid join in this case I would say as subquery would do good in this case.

Answer 7

从表1选择t1.id，t1.name，t1.type，t2.key，t2.value t1加入JOIN table2 t2开启t1.id = t2.parent_id其中t2.key <>'active'