MySQL查詢幫助需要

可能重複：
complex my sql query wrong results MySQL查詢幫助需要

我試圖構建複雜的MySQL查詢，但其返回錯誤結果...

SELECT b.name AS batch_name, b.id AS batch_id, 
     COUNT(DISTINCT s.id) AS total_students, 
     COALESCE(sum(s.open_bal), 0) AS open_balance, 
     sum(COALESCE(i.reg_fee,0) + COALESCE(i.tut_fee,0) + COALESCE(i.other_fee,0)) AS gross_fee, 
     sum(COALESCE(i.discount,0)) AS discount, 
     COALESCE(sum(s.open_bal), 0) + sum(COALESCE(i.reg_fee,0) + COALESCE(i.tut_fee,0) + COALESCE(i.other_fee,0)) - sum(COALESCE(i.discount,0)) AS net_payable, 
     sum(COALESCE(r.reg_fee,0) + COALESCE(r.tut_fee,0) + COALESCE(r.other_fee,0)) AS net_recieved, 
     (COALESCE(sum(s.open_bal), 0) + sum(COALESCE(i.reg_fee,0) + COALESCE(i.tut_fee,0) + COALESCE(i.other_fee,0)) - sum(COALESCE(i.discount,0))) - (sum(COALESCE(r.reg_fee,0) + COALESCE(r.tut_fee,0) + COALESCE(r.other_fee,0))) AS balance_due 
     FROM batches b 
     LEFT JOIN students s on s.batch = b.id 
     LEFT JOIN invoices i on i.student_id = s.id 
     LEFT JOIN recipts r on r.student_id = s.id 
     WHERE s.inactive = 0 
     GROUP BY b.name, b.id;

我是因爲sum（open_bal）結果是錯誤的，所以做錯了。

樣品結果...

| batch_name | total_students | open_bal | gross_fee | discount | net_payable | net_recieved | due_balance | 
+------------+-----------------+----------+-----------+----------+-------------+--------------+-------------+ 
| MS  | 6    | 10000 | 0   | 0  | 10000  | 101000  | -91000  | 
+------------+-----------------+----------+-----------+----------+-------------+--------------+-------------+

以上結果是錯誤的，請檢查下面的表結構

學生表

| id | open_bal | batch | 
+-----+----------+-------+ 
| 44 | -16000 | 9  | 
+-----+----------+-------+ 
| 182 | 9000  | 9  | 
+-----+----------+-------+ 
| 184 | -36000 | 9  | 
+-----+----------+-------+ 
| 185 | 19000 | 9  | 
+-----+----------+-------+ 
| 186 | 9000  | 9  | 
+-----+----------+-------+ 
| 187 | 4000  | 9  | 
+-----+----------+-------+

發票表

| id | student_id | reg_fee | tut_fee | other_fee | net_payable | discount | 
+------+------------+---------+---------+-----------+-------------+----------+ 
|  |   |   |   |   |    |   | 
+------+------------+---------+---------+-----------+-------------+----------+

沒有發票可用於以上學生ID。

Recipts表

| id | student_id | reg_fee | tut_fee | other_fee | status  | 
+------+------------+---------+---------+-----------+------------+ 
| 8 | 44   | 0  | 0  | 1500  | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 277 | 44   | 0  | 50000 | 0   | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 26 | 182  | 0  | 0  | 1500  | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 424 | 182  | 0  | 15000 | 0   | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 468 | 182  | 0  | 15000 | 0   | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 36 | 185  | 0  | 0  | 1500  | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 697 | 185  | 0  | 15000 | 0   | confirmed | 
+------+------------+---------+---------+-----------+------------+ 
| 66 | 187  | 0  | 0  | 1500  | confirmed | 
+------+------------+---------+---------+-----------+------------+

使用上面的SQL查詢和表格預期結果...

| batch_name | total_students | open_bal | gross_fee | discount | net_payable | net_recieved | due_balance | 
+------------+-----------------+----------+-----------+----------+-------------+--------------+-------------+ 
| MS  | 6    | -11000 | 0   | 0  | 10000  | 101000  | -112000  | 
+------------+-----------------+----------+-----------+----------+-------------+--------------+-------------+

請檢查並回復，謝謝。

來源

2011-10-12 seoppc

精確轉貼。請不要轉發您近期詢問的問題，@seoppc。謝謝。 –

@Jordan是的，我創造了新的問題。我真的很困惑，請幫助。 – seoppc

您必須將student_id添加到GROUP BY表達式中。

您正在創建多個外連接，這意味着所有數據將用於查詢中，但收據表中的某些學生也有多行，因此它們的金額會被複制（因爲會有與該s.id幾行）。

採取以下加入一看：

 r.id  s.id  open_bal 
     -------------------------- 
     8  | 44 | -16000 
     277  | 44 | -16000 
     26  | 182 | 9000 
     424  | 182 | 9000 
     468  | 182 | 9000 
     36  | 185 | 19000 
     697  | 185 | 19000 
     66  | 187 | 4000 
     null | 184 | -36000 
     null | 186 | 9000

概括起來，你會被前面的問題（以上）的同一用戶獲得10萬

來源

2011-10-12 11:39:44 Relja

可以請你發佈sql查詢嗎？如果我寫GROUP BY r.student_id，b.name，b.id然後我得到的所有數據由r.id分組而不是b.name – seoppc

MySQL查詢幫助需要

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