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选择聚合函数和MySQL中的所有其他列

2024-04-30 00:07:06 376

让我们首先创建一个表-

mysql> create table DemoTable1621
    -> (
    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
    -> StudentName varchar(20),
    -> StudentMarks int
    -> );

使用插入命令在表中插入一些记录-

mysql> insert into DemoTable1621(StudentName,StudentMarks) values('Chris',45);
mysql> insert into DemoTable1621(StudentName,StudentMarks) values('Bob',78);
mysql> insert into DemoTable1621(StudentName,StudentMarks) values('David',89);
mysql> insert into DemoTable1621(StudentName,StudentMarks) values('Adam',87);

使用select语句显示表中的所有记录-

mysql> select * from DemoTable1621;

这将产生以下输出-

+-----------+-------------+--------------+
| StudentId | StudentName | StudentMarks |
+-----------+-------------+--------------+
|         1 | Chris       |           45 |
|         2 | Bob         |           78 |
|         3 | David       |           89 |
|         4 | Adam        |           87 |
+-----------+-------------+--------------+
4 rows in set (0.00 sec)

以下是选择聚合函数的查询-

mysql> select tblData.*,( select max(StudentMarks) from DemoTable1621) as MaximumMarks from DemoTable1621 tblData;

这将产生以下输出-

+-----------+-------------+--------------+--------------+
| StudentId | StudentName | StudentMarks | MaximumMarks |
+-----------+-------------+--------------+--------------+
|         1 | Chris       |           45 |           89 |
|         2 | Bob         |           78 |           89 |
|         3 | David       |           89 |           89 |
|         4 | Adam        |           87 |           89 |
+-----------+-------------+--------------+--------------+
4 rows in set (0.00 sec)

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选择聚合函数和MySQL中的所有其他列

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