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2024年3月19日发(作者:设计模式 菜鸟)

数据库记录查询删除与修改的核心算法Java代码

下面是一个示例的数据库记录查询、删除和修改的核心算法的Java

代码:

```java

import .*;

public class DatabaseOperations

private Connection conn;

private Statement stmt;

//连接数据库

public void connect( throws SQLException

String url = "jdbc:mysql://localhost:3306/mydb";

String user = "root";

String password = "password";

conn = nection(url, user, password);

}

//查询记录

public void queryRecords(String tableName) throws

SQLException

stmt = Statement(;

String sql = "SELECT * FROM " + tableName;

ResultSet result = eQuery(sql);

//遍历结果集并输出记录

while (()

int id = ("id");

String name = ing("name");

int age = ("age");

n("ID: " + id + ", Name: " + name + ", Age:

" + age);

}

(;

}

//删除记录

public void deleteRecord(int id) throws SQLException

stmt = Statement(;

String sql = "DELETE FROM records WHERE id = " + id;

eUpdate(sql);

n("Record deleted successfully.");

(;

}

//修改记录

public void updateRecord(int id, String name, int age)

throws SQLException

stmt = Statement(;

String sql = "UPDATE records SET name = '" + name + "', age

= " + age + " WHERE id = " + id;

eUpdate(sql);

n("Record updated successfully.");

(;

}

//关闭数据库连接

public void closeConnection( throws SQLException

(;

}

public static void main(String[] args)

try

DatabaseOperations db = new DatabaseOperations(;

t(;

//查询记录

n("Querying records:");

ecords("records");

//删除记录

int recordIdToDelete = 1;

n("Deleting record with ID " +

recordIdToDelete + ":");

Record(recordIdToDelete);

ecords("records");

//修改记录

int recordIdToUpdate = 2;

String updatedName = "John";

int updatedAge = 30;

n("Updating record with ID " +

recordIdToUpdate + ":");

Record(recordIdToUpdate, updatedName, updatedAge);

ecords("records");

onnection(;

} catch (SQLException e)

tackTrace(;

}

}

```

上面的代码包含了一个`DatabaseOperations`类,该类封装了与数据

库的连接和操作。在`main`方法中,我们通过创建一个

`DatabaseOperations`对象来执行以下操作:

1.连接数据库

2.查询记录

3.删除记录

4.修改记录

5.关闭数据库连接

你可以根据自己的需求来修改和扩展这个类,例如添加插入记录的方

法等。请注意,上述代码仅作为示例,你需要根据你的数据库结构和需求

进行相应的修改。同时,你需要根据实际情况修改数据库连接URL、用户

名和密码。


本文标签: 记录 修改 数据库 连接 删除