Question

这是我的情况：我有两个表，表A有列：

  ID,
  Name,
  ClassYear,
  Classmonth

ID是主键，没有重复。

表b包含以下列：

    ID,
    addresstype
    addline1
    addline2
    country,
    city,
    state,
    zip

ID在table B中不是唯一的，但这是您链接回table A的方式。

如果您有多个address，例如Home，school，那么您在table b中的记录已超过记录。

我的任务是从table A中选择class year为>= 2019的所有人，并选择class year = 2018为class month的所有人。 >=5

我没问题。

现在让我感到困惑的是，我有来自table A的人员列表，我需要查询table b，而我只想提取同时拥有home和school地址类型和地址相同，例如line 1，line 2，country，city，state，zip都是相同的。

我将不胜感激。

Answer 1

您可以按地址的详细信息分组并计算其具有的不同类型的数量：

SELECT *
FROM   table1
WHERE  id IN (SELECT   id
              FROM     table2
              WHERE    addresstype IN ('home', 'school')
              GROUP BY id, addline1, addline2, country, city, state, zip
              HAVING   COUNT(DISTINCT addresstype) = 2)

Answer 2

SELECT
    DISTINCT
    student.ID
    , student.Name
    , student.ClassYear
    , student.ClassMonth
FROM
    TableA AS student
    INNER JOIN TableB AS homeAddress ON
        student.ID = homeAddress.ID
        AND homeAddress.addressType = 'Home'
    INNER JOIN TableB AS schoolAddress ON
        student.ID = schoolAddress.ID
        AND schoolAddress.addressType = 'School'
        AND homeAddress.line1 = schoolAddress.line1
        AND homeAddress.line2 = schoolAddress.line2
        AND homeAddress.country = schoolAddress.country
        AND homeAddress.city = schoolAddress.city
        AND homeAddress.state = schoolAddress.state
        AND homeAddress.zip = schoolAddress.zip
WHERE
    student.classYear >= 2019
    OR (student.ClassYear = 2018 AND student.classMonth >= 5)
;

SQL查询让我感到困惑

2 个答案: