Question

我把所有父亲和母亲的人表都放在同一张孩子的桌子上

Pen-id     firstname  lastname gender  father-id mother-id
10002       Ti         Si-dao   M       null    null
10025       Leonardo    Vogel   M       10002   10010
10010       Marissa     Wilkes  F       null    null

我需要查看以显示以下句子

Ti是Leonardo Vogel的父亲玛丽莎是莱昂纳多沃格尔的母亲

我使用了DDL但它没有用

CREATE VIEW parent AS
    SELECT (FIRSTNAME) ||' '|| (LASTNAME)|| (CASE WHEN GENDER ='F' THEN ' is the mother of'  ELSE 'is the father of' END) ||' '|| (FIRSTNAME) ||' '|| (LASTNAME)  AS PARENTAGE
    FROM P_PERSON ;

Answer 1

此查询将根据需要为您提供输出但也请考虑以下注释。

    select t2.firstname || ' Is Father Of '|| t1.firstname ||' '||t1.lastname 
    ||' , '||t3.firstname ||' Is Mother Of ' ||t1.firstname ||' '||t1.lastname as PARENTAGE
 from  P_PERSON  t1 , P_PERSON  t2 , P_PERSON  t3 where t1.father_id is not NULL 
    and t1.mother_id is not NULL and t1.father_id=t2.pen_id and t1.mother_id=t3.pen_id;

点击Fiddle

注意：上表是错误数据库设计的示例。理想的是你的数据库应该在3NF以实现最大性能。如果可能的话修改数据库设计。这会使Child和Parent变得不同对象/表减少头痛。

<强>更新

要在单独的行中输出，您可以使用union

        select t2.firstname || ' Is Father Of '|| t1.firstname ||' '||t1.lastname 
        as PARENTAGE from P_PERSON  t1 , P_PERSON  t2  
        where t1.father_id is not NULL and t1.father_id=t2.pen_id 
        union
        select t3.firstname ||' Is Mother Of ' ||t1.firstname ||' '||t1.lastname as 
        PARENTAGE from P_PERSON  t1 ,  P_PERSON  t3 where  t1.mother_id is not NULL and 
        t1.mother_id=t3.pen_id;

点击Example

选择具有来自同一表Oracle的父级的子级

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