如何在不使用聚合函数的情况下在MySQL中添加列值？

  • Z时代
  • 2024-01-10
  • 分类：综合

您可以添加列值，而无需使用聚合函数sum()。为此，语法如下-

SELECT *,(yourColumnName1+yourColumnName2+yourColumnName3,....N) as
anyVariableName from yourTableName;

为了理解上述语法，让我们创建一个表。创建表的查询如下-

mysql> create table AddingColumnDemo
   -> (
   -> StudentId int,
   -> StudentName varchar(20),
   -> MathMarks int,
   -> PhysicsMarks int,
   -> ChemistryMarks int
   -> );

使用insert命令在表中插入记录。查询如下-

mysql> insert into AddingColumnDemo values(1,'John',35,45,76);
mysql> insert into AddingColumnDemo values(2,'Bob',67,76,88);
mysql> insert into AddingColumnDemo values(3,'Carol',45,56,43);
mysql> insert into AddingColumnDemo values(4,'Mike',82,75,71);
mysql> insert into AddingColumnDemo values(5,'Sam',92,89,88);

使用select语句显示表中的所有记录-

mysql> select *from AddingColumnDemo;

以下是显示表记录的输出-

+-----------+-------------+-----------+--------------+----------------+
| StudentId | StudentName | MathMarks | PhysicsMarks | ChemistryMarks |
+-----------+-------------+-----------+--------------+----------------+
|         1 | John        |        35 |           45 |             76 |
|         2 | Bob         |        67 |           76 |             88 |
|         3 | Carol       |        45 |           56 |             43 |
|         4 | Mike        |        82 |           75 |             71 |
|         5 | Sam         |        92 |           89 |             88 |
+-----------+-------------+-----------+--------------+----------------+
5 rows in set (0.00 sec)

现在让我们实现查询以在MySQL中添加列值-

mysql> select *,(MathMarks+PhysicsMarks+ChemistryMarks) as TotalResult from AddingColumnDemo;

以下是显示TotalResult列中列值总和的输出-

+-----------+-------------+-----------+--------------+----------------+-------------+
| StudentId | StudentName | MathMarks | PhysicsMarks | ChemistryMarks | TotalResult |
+-----------+-------------+-----------+--------------+----------------+-------------+
|         1 | John        |        35 |           45 |             76 |         156 |
|         2 | Bob         |        67 |           76 |             88 |         231 |
|         3 | Carol       |        45 |           56 |             43 |         144 |
|         4 | Mike        |        82 |           75 |             71 |         228 |
|         5 | Sam         |        92 |           89 |             88 |         269 |
+-----------+-------------+-----------+--------------+----------------+-------------+
5 rows in set (0.00 sec)

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