Database
Users
| id | lastname | firstname |
|---|---|---|
| 1 | Sardor | Sattarov |
| 2 | Nurmuhammad | To’xtayev |
| 3 | Jasur | Sattarov |
Group_items
| id | student_id | group_id |
|---|---|---|
| 1 | 2 | 55 |
| 2 | 1 | 55 |
| 3 | 2 | 11 |
Return example 1
condition
users.id == group_items.student_id do not publish a table that satisfies this desire group_items.id == 55
| id | lastname | firstname |
|---|---|---|
| 3 | Jasur | Sattarov |
example 2
condition
users.id == group_items.student_id do not publish a table that satisfies this desire group_items.id == 11
| id | lastname | firstname |
|---|---|---|
| 1 | Sardor | Sattarov |
| 3 | Jasur | Sattarov |
CodePudding user response：
Looks like you want OR instead of AND.
SELECT
*
FROM
users u
LEFT JOIN group_items gi ON u.id = gi.student_id
WHERE
gi.student_id IS NULL
OR gi.group_id <> 5
Studends without a group plus studends in all groups but 5.
CodePudding user response：
Please try this,
Example 1:
SELECT
U.ID,U.LASTNAME,U.FIRSTNAME
FROM
USERS U
LEFT JOIN
GROUP_ITEMS G
ON U.ID=G.STUDENT_ID
WHERE G.GROUP_ID <>55
Example 2:
SELECT
U.ID,U.LASTNAME,U.FIRSTNAME
FROM
USERS U
LEFT JOIN
GROUP_ITEMS G
ON U.ID=G.STUDENT_ID
WHERE G.GROUP_ID <>11
CodePudding user response：
You can use join statements in SQL
For Example for return 1:
SELECT * FROM users u left join group_items gi on gi.student_id = u.id
this query will return all students with their group_id for filter by group you can use where statement.
SELECT * FROM users u left join group_items gi on gi.student_id = u.id where gi.group_id<>11