php - 查询连接给我重述结果 mysql php

Question

我在 mysql 中有一个查询返回我重复的结果我想要结果唯一。例如在我的例子中我有公司名称它返回我重复的名字，id。

SELECT 
      company.name,
      company.id,
      branchInfo.name,
      branches.visible 
FROM branches  
INNER JOIN users branchInfo ON branches.branchId=branchInfo.id 
INNER JOIN users company ON branches.companyId=company.id   
WHERE branches.visible=1 

它会返回多次重复的数据，所以我希望它是唯一的。

Answer 1

您可以使用 DISTINCT或 GROUP BY ，它们不一样，但在您的示例中，您会得到相同的结果。

如果您只想删除重复项，请使用 DISTINCT。如果您想应用聚合运算符，请使用 GROUPY BY，例如:AVG、MAX、MIN、SUM 和 COUNT

试试这个:

SELECT 
  company.name,
  company.id,
  branchInfo.name,
  branches.visible 
FROM branches  
INNER JOIN users branchInfo ON branches.branchId=branchInfo.id 
INNER JOIN users company ON branches.companyId=company.id   
WHERE branches.visible=1 
GROUPY BY company.name

或者这个:

SELECT 
  DISTINCT(company.name),
  company.id,
  branchInfo.name,
  branches.visible 
FROM branches  
INNER JOIN users branchInfo ON branches.branchId=branchInfo.id 
INNER JOIN users company ON branches.companyId=company.id   
WHERE branches.visible=1;

Group by : clause is used in collaboration with the SELECT statement to arrange identical data into groups. This GROUP BY clause follows the WHERE clause in a SELECT statement and precedes the ORDER BY clause.

DISTINCT keyword is used in conjunction with the SELECT statement to eliminate all the duplicate records and fetching only unique records.

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