mysql - SQL INNER JOIN 返回空结果

Question

我想从两个表中获取数据。为此，我使用内部连接进行连接。第一个表包含我想要的所有详细信息，第二个表包含比该数据更多的详细信息。

查询数据后，我得到第二个表值的空数据。

SELECT * FROM 
          facility_costdel as fc 
          LEFT OUTER JOIN 
          basic_facility_del as bf
          on fc.facility_code = bf.facility_code

我的查询有问题吗？

Answer 1

您尝试的内容是正确的..如果有任何匹配的数据，它应该返回行。 那么没有返回结果有三种可能

1. There is no matching facility_code between two tables.
2. If matching facility_code is there then match case can be different..
   (lower case and upper case)
3. Third case is leading or trailing spaces.

我猜你正在使用sql server..尝试下面的代码

SELECT * FROM 
          facility_costdel as fc 
          JOIN 
          basic_facility_del as bf
          on ltrim(rtrim(fc.facility_code)) = ltrim(rtrim(bf.facility_code))