MySQL 查詢來找到具有相同列值欄位的總和?
為此使用 GROUP BY 子句。我們首先建立一個表 -
mysql> create table sumOfFieldsDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> ClientSerialNumber varchar(100), -> ClientCost int -> ); Query OK, 0 rows affected (0.50 sec)
以下是使用 insert 命令在表中插入一些記錄的查詢 -
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('1111',450);
Query OK, 1 row affected (0.16 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('2222',550);
Query OK, 1 row affected (0.15 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('3333',150);
Query OK, 1 row affected (0.64 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('3333',250);
Query OK, 1 row affected (0.12 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('2222',1000);
Query OK, 1 row affected (0.10 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('1111',1000);
Query OK, 1 row affected (0.16 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('1111',500);
Query OK, 1 row affected (0.17 sec)
mysql> insert into sumOfFieldsDemo(ClientSerialNumber,ClientCost) values('4444',100);
Query OK, 1 row affected (0.17 sec)以下是使用 select 語句從表中顯示所有記錄的查詢 -
mysql> select * from sumOfFieldsDemo;
將生成以下輸出 -
+----+--------------------+------------+ | Id | ClientSerialNumber | ClientCost | +----+--------------------+------------+ | 1 | 1111 | 450 | | 2 | 2222 | 550 | | 3 | 3333 | 150 | | 4 | 3333 | 250 | | 5 | 2222 | 1000 | | 6 | 1111 | 1000 | | 7 | 1111 | 500 | | 8 | 4444 | 100 | +----+--------------------+------------+ 8 rows in set (0.00 sec)
以下是查詢具有相同列值的欄位總和的查詢 -
mysql> select Id,ClientSerialNumber,SUM(ClientCost) AS TotalSum -> from sumOfFieldsDemo -> group by ClientSerialNumber;
將生成以下輸出 -
+----+--------------------+----------+ | Id | ClientSerialNumber | TotalSum | +----+--------------------+----------+ | 1 | 1111 | 1950 | | 2 | 2222 | 1550 | | 3 | 3333 | 400 | | 8 | 4444 | 100 | +----+--------------------+----------+ 4 rows in set (0.00 sec)
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