How to write a sql query to do multiple joins with the same table
Question
I am trying to write a SQL query to fetch data from two tables. One table A has 9 fields which are primary key relation to table B.
SELECT JBO8.posid
, JbO8.actnm
, JBO8.prntposid
, JBO8.lngcd
, JBO8.H0
, JBO8.h1
, JBO8.h2
, JBO8.h3
, JBO8.h4
, JBO8.h5
, JBO8.H6
, JBO8.H7
, JBO8.H8
, organization.name AS H9
FROM (
SELECT JBO7.posid
, JbO7.actnm
, JBO7.prntposid
, JBO7.lngcd
, JBO7.H0
, JBO7.h1
, JBO7.h2
, JBO7.h3
, JBO7.h4
, JBO7.h5
, JBO7.H6
, JBO7.H7
, organization.name AS H8
, JBO7.hierarchylvl9
FROM (
SELECT JBO6.posid
, JbO6.actnm
, JBO6.prntposid
, JBO6.lngcd
, JBO6.H0
, JBO6.h1
, JBO6.h2
, JBO6.h3
, JBO6.h4
, JBO6.h5
, JBO6.H6
, organization.name AS H7
, JBO6.hierarchylvl8
, JBO6.hierarchylvl9
FROM (
SELECT JBO5.posid
, JbO5.actnm
, JBO5.prntposid
, JBO5.lngcd
, JBO5.H0
, JBO5.h1
, JBO5.h2
, JBO5.h3
, JBO5.h4
, JBO5.h5
, organization.name AS H6
, JBO5.hierarchylvl7
, JBO5.hierarchylvl8
, JBO5.hierarchylvl9
FROM (
SELECT JBO4.posid
, JbO4.actnm
, JBO4.prntposid
, JBO4.lngcd
, JBO4.H0
, JBO4.h1
, JBO4.h2
, JBO4.h3
, JBO4.h4
, organization.name AS H5
, JBO4.hierarchylvl6
, JBO4.hierarchylvl7
, JBO4.hierarchylvl8
, JBO4.hierarchylvl9
FROM (
SELECT JBO3.posid
, JbO3.actnm
, JBO3.prntposid
, JBO3.lngcd
, JBO3.H0
, JBO3.h1
, JBO3.h2
, JBO3.h3
, organization.name AS H4
, JBO3.hierarchylvl5
, JBO3.hierarchylvl6
, JBO3.hierarchylvl7
, JBO3.hierarchylvl8
, JBO3.hierarchylvl9
FROM (
SELECT JBO2.posid
, JbO2.actnm
, JBO2.prntposid
, JBO2.lngcd
, JBO2.H0
, JBO2.h1
, JBO2.h2
, organization.name AS H3
, JBO2.hierarchylvl4
, JBO2.hierarchylvl5
, JBO2.hierarchylvl6
, JBO2.hierarchylvl7
, JBO2.hierarchylvl8
, JBO2.hierarchylvl9
FROM (
SELECT JBO1.posid
, JbO1.actnm
, JBO1.prntposid
, JBO1.lngcd
, JBO1.H0
, JBO1.h1
, organization.name AS H2
, JBO1.Hierarchylvl3
, JBO1.hierarchylvl4
, JBO1.hierarchylvl5
, JBO1.hierarchylvl6
, JBO1.hierarchylvl7
, JBO1.hierarchylvl8
, JBO1.hierarchylvl9
FROM (
SELECT JBO0.posid
, JbO0.actnm
, JBO0.prntposid
, JBO0.lngcd
, JBO0.H0
, organization.name AS h1
, JBO0.hierarchylvl2
, JBO0.Hierarchylvl3
, JBO0.hierarchylvl4
, JBO0.hierarchylvl5
, JBO0.hierarchylvl6
, JBO0.hierarchylvl7
, JBO0.hierarchylvl8
, JBO0.hierarchylvl9
FROM (
SELECT posid
, actnm
, prntposid
, lngcd
, Organization.Name AS H0
, Hierarchylvl1
, hierarchylvl2
, hierarchylvl3
, hierarchylvl4
, hierarchylvl5
, hierarchylvl6
, hierarchylvl7
, hierarchylvl8
, hierarchylvl9
FROM Jobposition
JOIN Organization ON Jobposition.Hierarchylvl0 = organization.OrganizationPk
) AS JBO0
JOIN Organization ON JBO0.hierachylvl1 = organization.organizationpk
) AS JBO1
JOIN organization ON Jbo1.hierarchylvl2 = organization.organizationpk
) AS JBO2
JOIN Organization ON JBO2.hierarchylvl3 = organization.organizationpk
) AS JBO3
JOIN Organization ON JBO3.hierarchylvl4 = organization.organizationpk
) AS JBO4
JOIN Organization ON JBO4.hierarchylvl5 = organization.organizationpk
) AS JBO5
JOIN Organization ON JBO5.hierarchylvl6 = organization.organizationpk
) AS JBO6
JOIN Organization ON JBO6.hierarchylvl7 = organization.organizationpk
) AS JBO7
JOIN Organization ON JBO7.hierarchylvl8 = organization.organizationpk
) AS JBO8
JOIN Organization ON JBO8.hierarchylvl9 = organization.organizationpk
I am not sure if What I am trying to do is allowed in SQL
1 answers
solution1
4 2019-09-11 18:11:20
It looks like you're trying to do the below:
SELECT posid
, actnm
, prntposid
, lngcd
, o0.Name AS H0
, o1.Name AS H1
, o2.Name AS H2
, o3.Name AS H3
, o4.Name AS H4
, o5.Name AS H5
, o6.Name AS H6
, o7.Name AS H7
, o8.Name AS H8
, o9.Name AS H9
FROM Jobposition jp
JOIN Organization o0 ON jp.Hierarchylvl0 = o0.OrganizationPk
JOIN Organization o1 ON jp.Hierarchylvl1 = o1.OrganizationPk
JOIN Organization o2 ON jp.Hierarchylvl2 = o2.OrganizationPk
JOIN Organization o3 ON jp.Hierarchylvl3 = o3.OrganizationPk
JOIN Organization o4 ON jp.Hierarchylvl4 = o4.OrganizationPk
JOIN Organization o5 ON jp.Hierarchylvl5 = o5.OrganizationPk
JOIN Organization o6 ON jp.Hierarchylvl6 = o6.OrganizationPk
JOIN Organization o7 ON jp.Hierarchylvl7 = o7.OrganizationPk
JOIN Organization o8 ON jp.Hierarchylvl8 = o8.OrganizationPk
JOIN Organization o9 ON jp.Hierarchylvl9 = o9.OrganizationPk
Note that if any of the hierarchy fields are nullable, you'll need to change out all those joins to be LEFT JOIN.
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.
Related Question
SQL Query Multiple Joins to same table
How to write a query that joins same table in sql and compares the column values of one table with same column in another table
SQL how to use multiple joins on the same table
Multiple sql joins same table
SQL multiple joins on the same table
Need to perform mathematical operation on SQL query with multiple joins on same table
Improve SQL Server Query With Multiple Joins To Same Table
Structure query builder generated SQL statement? Multiple joins to the same table?
How to do multiple joins on the same table with the same source with same coulmn?
SQL Count + 3 joins + multiple where in one query - how write propen IF?
Related Tags