php MySql 连接表，Table.A 名称匹配 Table.B 列名称

Question

我已经尝试了所有我能想到的方法。问题。主表具有与第二个表名称匹配的列。我不能加入。有什么帮助吗？

SELECT 
    Inspections.Id,
    Inspections.Custom_Specs,
    Custom_Specs.Id AS Custom_Id                
FROM Inspections
    JOIN Custom_Specs ON Inspections.Custom_Specs=Custom_Specs.Id

Inspections.Id,           (Value: 1)
Inspections.Custom_Specs, (Value: 5)
Custom_Specs.Id,          (Value: 5)
Custom_Specs.Spec_Name ,   (Value: Name Of Spec)
Custom_Specs.Id AS Specs_Id

输出:

<option value=\"". $row["Specs_Id."] ."\">". $row["Spec_Name"] ."</option>

更新:

对我有用的查询:

SELECT 
   Inspections.Id, 
   Inspections.Custom_Specs, 
   Custom_Specs.Id, 
   Custom_Specs.Spec_Name
FROM Inspections 
LEFT JOIN Custom_Specs ON Inspections.Custom_Specs = Custom_Specs.Id

Answer 1

您将规范与 id 列进行比较。这是两种不同的数据类型。下面的查询应该可以为您完成工作:

SELECT 
   Custom_Specs.Id
   Custom_Specs.Spec_Name
FROM Inspections
LEFT JOIN Custom_Specs ON Inspections.Custom_Specs = Custom_Specs.Id