php - MySQL 查询不返回任何内容或返回错误数据

Question

我有两张 table 。 Table_1 有此字段。

table_1_id
name
image
adres

表_2

table_2_id
name
email
phone
comment
datetime
need_id

我想在点击 ID_1 表单 table_1 时加载 table_2 中具有 table_1_id = 的所有行1 我尝试过这个查询

SELECT t1*, t2.* FROM table_1 t1, table_2 t2
                 WHERE t1.table_1_id = t2.need_id ORDER BY `DateTime` DESC

并显示空白页。然后我尝试了这样的

SELECT t1.*, t2.* FROM table_1 t1
 JOIN table_2 t2 ON t1.table_1_id = t2.need_id ORDER BY ` DateTime` DESC 

无论我点击什么，都会从数据库返回前 5 个结果，仅此而已。

Answer 1

假设您有 ID_1，则不需要在查询中涉及 table_1:

SELECT * FROM table_2
WHERE need_id = ID_1 
ORDER BY `DateTime` DESC