java数据库增删改查
时间: 2023-10-02 12:10:19 浏览: 47
Java 中操作数据库的增删改查通常使用 JDBC(Java Database Connectivity)连接数据库。下面是一个简单的示例:
1. 导入 JDBC 驱动程序
```java
Class.forName("com.mysql.jdbc.Driver");
```
2. 建立数据库连接
```java
String url = "jdbc:mysql://localhost:3306/test";
String user = "root";
String password = "123456";
Connection conn = DriverManager.getConnection(url, user, password);
```
3. 执行 SQL 语句
a. 查询数据
```java
String sql = "SELECT * FROM student";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println(id + "\t" + name + "\t" + age);
}
```
b. 插入数据
```java
String sql = "INSERT INTO student (name, age) VALUES ('Tom', 18)";
Statement stmt = conn.createStatement();
int result = stmt.executeUpdate(sql);
if (result > 0) {
System.out.println("插入成功!");
} else {
System.out.println("插入失败!");
}
```
c. 更新数据
```java
String sql = "UPDATE student SET age = 20 WHERE name = 'Tom'";
Statement stmt = conn.createStatement();
int result = stmt.executeUpdate(sql);
if (result > 0) {
System.out.println("更新成功!");
} else {
System.out.println("更新失败!");
}
```
d. 删除数据
```java
String sql = "DELETE FROM student WHERE name = 'Tom'";
Statement stmt = conn.createStatement();
int result = stmt.executeUpdate(sql);
if (result > 0) {
System.out.println("删除成功!");
} else {
System.out.println("删除失败!");
}
```
4. 关闭数据库连接
```java
rs.close();
stmt.close();
conn.close();
```
以上就是一个简单的 Java 数据库增删改查的示例。需要注意的是,这里的代码仅供参考,实际应用中还需要进行错误处理等操作。