I can´t manage to create a valid query that shows me 5 columns from these 4 tables: [![enter image description here][1]][1] [1]: https://i.sstatic.net/1AhfY.png As you can see the relationships that i'm trying to JOIN in the query are highlighted in differents colors. The query i came out is: SELECT c.CompanyName , s.categoryname , cprs.strenght , s.parentid , ss.Risklevel , ss.ColumnType FROM company_details AS c JOIN category_master AS s ON s.id = c.categoryid JOIN company_strenght AS cprs ON cprs.companyid = c.id JOIN subsector_detasils AS ss ON s.parentid = ss.subcategoryid But server gets unresponsive until i have to kill the process. The issue is in the last line, if i remove it and only manage 3 tables i get a successful result but is not enough for what i want. **Problem description:** The *company_details* table is a list of companies. The `id` field is an unique ID that each company has. We need to match that id with the `companyid` field in the *company_strenght* table so we can get the `c.CompanyName, s.categoryname, cprs.strenght` columns. All good so far. Then we need to include in the results the *category_master* table which contains the category that each company belongs to. So we match `s.id = c.categoryid`for that. Still no problem and i get a list of companies with the catergories they belong to and also their parent category id. **Finally here is the problem:** Each company has a parent category which id is `parentid` in the *category_master* table (marked in green). This `parentid` field is the same than the `subcategoryid` field in the *subsector_detasils* table. We need to match `s.parentid = ss.subcategoryid` so we can get `ss.Risklevel, ss.ColumnType` columns in the results. But as i said, it's not working since phpmyadmin just stops working and i have to kill the process manually. Is there any other way to get around this problem? I'm running out of ideas... Thanks in advance.