SELECT c.cost_center_name as cost_center_name,
COUNT(e.employee) as number_of_employees,
SUM(e.w2_wages) as total_wages,
c.qualified_percent,
c.qualified_percent*SUM(e.w2_wages)*.01 as qualified_wages
FROM cost_center as c
CROSS JOIN employees as e
LEFT OUTER JOIN employees e2 ON e.department = c.cost_center_name
GROUP BY cost_center_name
What is the problem in initial query? The precedence.
Comma has lower priority then JOIN. So FROM clause is totally
FROM cost_center as c, (
employees as e
LEFT OUTER JOIN employees e2 ON e.department=cost_center_name
)
And when 2 employees
copies are joined cost_center_name
column which is posessed in cost_center
table is not visible.
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