Multiple Left Join with sum

Question

I\'m trying to display in a table (with data tables plugin) informations with sum from 3 tables using Left Join in sql query. I succeeded to edit server-side query and disp

Answer 1

That is the final and seems to work.

$year=date('Y');
$sQuery = "SELECT SQL_CALC_FOUND_ROWS ".str_replace(" , ", " ", implode(", ", $aColumns)).", 
t2.total_changes,
t1.operation_BP+IFNULL(total_changes,0) AS operation_total, 
t3.total_conso
FROM $sTable AS t1
LEFT JOIN (SELECT tt2.change_year_operation, IFNULL(SUM(tt2.change_amount),0) AS total_changes FROM wp_dri_budget_changes tt2 GROUP BY tt2.change_year_operation) t2 ON t1.operation_year_number = t2.change_year_operation
LEFT JOIN (SELECT tt3.expense_year_operation, IFNULL(SUM(tt3.expense_enga_amount),0) AS total_conso FROM wp_dri_budget_expenses tt3 GROUP BY tt3.expense_year_operation) AS t3 ON t1.operation_year_number = t3.expense_year_operation
WHERE t1.operation_year=".$year." AND t1.operation_active=1 $sWhere $sOrder $sLimit";

OPERATION_NUMBER NAME BP CHANGES TOTAL TOTAL_CONSO

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15P731OV001 project1 28000 (null) 28000 (null)

13P0012OV001 project2 612500 -60000 552500 21000

**But now IFNULL(x,0) seems not working anymore and null (NaN.N in datatables) are display when sum results are NULL **