Friday, 5 July 2013

joining tables in queries Fo rms

I am not that versed at some advanced SQL but need to create a SELECT query using JOINS that links data across 4 tables. ( using * as the field selector for all tables)
Table 1 (Project Tasks) (Fields: parent_project_id, ...)
Table 2 (Parent Project Details) (Fields: id [KEY], dept_id, ...)
Table 3 (Department) (Fields: id [KEY], manager_id, ...)
Table 4 (Resources) (Fields: employee_id [KEY], email, ...) 

parent_project_id(Table 1) maps to id(Table 2)
dept_id(Table 2) maps to id(Table 3)
manager_id(Table 3) maps to employee_id(Table 4)
I would like to be able to return a list of Project Task details that include the Parent Project details, Department details, and Manager's details on each line.

Every SQL tutorial explains how to do joins.
SELECT *
FROM table1
JOIN table2 ON table1.parent_project_id = table2.id
JOIN table3 ON table2.dept_id = table3.id
JOIN table4 ON table3.manager_id = table4.employee_id
 
 

SQL Query to join two tables

 I have two tables without primary keys and with a common field meterid...
I can't add a primary key to any of these tables...
Now i need to join both tables..
Can anyone write the query for this...plss...
select * from table1,table2 where table1.meterid=table2.meterid; isn't working...
The result of the above query is the multiple of rows...

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