jsp实现简单增删改查
时间: 2023-07-08 13:35:33 浏览: 84
以下是使用 JSP 实现简单增删改查的示例:
1. 添加数据
```jsp
<%
// 获取表单传递的参数
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
String gender = request.getParameter("gender");
// 将数据插入数据库
Connection conn = null;
PreparedStatement ps = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
String sql = "INSERT INTO user(name, age, gender) VALUES (?, ?, ?)";
ps = conn.prepareStatement(sql);
ps.setString(1, name);
ps.setInt(2, age);
ps.setString(3, gender);
ps.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
%>
```
2. 查询数据
```jsp
<%
// 从数据库查询数据
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
String sql = "SELECT * FROM user";
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
while (rs.next()) {
String name = rs.getString("name");
int age = rs.getInt("age");
String gender = rs.getString("gender");
// 输出数据
out.println("Name: " + name + ", Age: " + age + ", Gender: " + gender + "<br>");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (rs != null) {
rs.close();
}
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
%>
```
3. 修改数据
```jsp
<%
// 获取表单传递的参数
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
String gender = request.getParameter("gender");
// 修改数据库中的数据
Connection conn = null;
PreparedStatement ps = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
String sql = "UPDATE user SET age=?, gender=? WHERE name=?";
ps = conn.prepareStatement(sql);
ps.setInt(1, age);
ps.setString(2, gender);
ps.setString(3, name);
ps.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
%>
```
4. 删除数据
```jsp
<%
// 获取表单传递的参数
String name = request.getParameter("name");
// 从数据库删除数据
Connection conn = null;
PreparedStatement ps = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "123456");
String sql = "DELETE FROM user WHERE name=?";
ps = conn.prepareStatement(sql);
ps.setString(1, name);
ps.executeUpdate();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
%>
```
注意:以上代码只是示例,实际应用中需要根据具体情况进行适当的修改和完善,例如添加数据时需要进行参数校验,查询数据时可能需要分页查询等。