mysql - 如何从一个表中查找另一个表中不存在的数据？

Question

我有 2 个表，如下所示。如何查看哪些data_entry的信息不在task_detail表中。

data_entry
+----+----------+----------+
| id | firstname| lastname |
+----+----------+----------+
| 1  | Anil     | Chaudhari|
+----+----------+----------+
| 2  | Sunil    | Chaudhari|
+----+----------+----------+
| 3  | Pranil   | Chaudhari|
+----+------+--------------+

task_detail
+----+-------+--------------+--------+
| id | de_id | field_name   | amount |
+----+-------+--------------+--------+
| 1  | 1     | firstname    | 0.1    |
+----+-------+--------------+--------+
| 2  | 1     | lastname     | 0.1    |
+----+-------+--------------+--------+

我只想

data_entry
+----+----------+----------+
| id | firstname|lastnamer |
+----+----------+----------+
| 2  | Sunil    | Chaudhari|
+----+----------+----------+
| 3  | Pranil   | Chaudhari|
+----+------+--------------+

Answer 1

也许这会起作用:

SELECT * FROM data_entry 
WHERE  id NOT IN (SELECT  de_id FROM task_detail)