如何让MySQL中单句实现无限层次父子关系查询

表结构和数据

CREATE TABLE table1(id int, name varchar(10), parent_id int)

INSERT table1 VALUES

(1, ‘Home’, 0),

(2, ‘About’, 1),

(3, ‘Contact’, 1),

(4, ‘Legal’, 2),

(5, ‘Privacy’, 4),

(6, ‘Products’, 1),

(7, ‘Support’, 2)

查询 id = 5 的所有父级

SELECT ID.level, DATA.* FROM(

SELECT

@id as _id,

( SELECT @id := parent_id

FROM table1

WHERE id = @id

) as _pid,

当然这种结构就不要追求什么效率了。如果要效率高的，只能改表结构。

1：select p2.id from table p1 ,table p2 where p1.id=p2.pid and p1.id=0

2：假设表名是tree

SQL codeselect distinct a.id from tree as a inner join tree as b on (a.pid = b.pid) where b.pid >=0

select distinct a.id from tree as a inner join tree as b on (a.pid = b.pid) where b.pid >=2

3.通过程序或数据库的store procedure来实现了。 在mySQL中无法以一句SQL实现。

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