From d56c40d08e9537dda38edc00106c84f72dffc688 Mon Sep 17 00:00:00 2001 From: wks20050721 <2568429394@qq.com> Date: Wed, 29 May 2024 12:31:29 +0800 Subject: [PATCH] =?UTF-8?q?feat=EF=BC=9A=E6=8F=90=E4=BA=A4=E4=BD=9C?= =?UTF-8?q?=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../QueryAllTeachers.java" | 66 +++++++++++++++++++ .../QueryTeacherByIdAndAge.java" | 56 ++++++++++++++++ .../UpdateTeacherName.java" | 61 +++++++++++++++++ 3 files changed, 183 insertions(+) create mode 100644 "work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryAllTeachers.java" create mode 100644 "work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryTeacherByIdAndAge.java" create mode 100644 "work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/UpdateTeacherName.java" diff --git "a/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryAllTeachers.java" "b/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryAllTeachers.java" new file mode 100644 index 0000000..33afffe --- /dev/null +++ "b/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryAllTeachers.java" @@ -0,0 +1,66 @@ +package com.java.minxi.java_20240524.java_2302_王开社_2344310220; + +import java.sql.*; + +public class QueryAllTeachers { + public static void main(String[] args) { + // JDBC 驱动名和数据库 URL + final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver"; + final String DB_URL = "jdbc:mysql://localhost:3306/student"; + + // 数据库用户名和密码 + final String USER = "username"; + final String PASS = "password"; + + Connection conn = null; + Statement stmt = null; + + try{ + // 注册 JDBC 驱动 + Class.forName(JDBC_DRIVER); + + // 打开连接 + conn = DriverManager.getConnection(DB_URL,USER,PASS); + + // 执行查询 + stmt = conn.createStatement(); + String sql = "SELECT id, teacher_name, teacher_age FROM teacher_info"; + ResultSet rs = stmt.executeQuery(sql); + + // 提取数据 + while(rs.next()){ + // 通过字段检索 + int id = rs.getInt("id"); + String teacherName = rs.getString("teacher_name"); + int age = rs.getInt("teacher_age"); + + // 输出数据 + System.out.print("ID: " + id); + System.out.print(", 名称: " + teacherName); + System.out.println(", 年龄: " + age); + } + + // 清理环境 + rs.close(); + stmt.close(); + conn.close(); + }catch(SQLException se){ + // 处理 JDBC 错误 + se.printStackTrace(); + }catch(Exception e){ + // 处理 Class.forName 错误 + e.printStackTrace(); + }finally{ + // 关闭资源 + try{ + if(stmt!=null) stmt.close(); + }catch(SQLException se2){ + } + try{ + if(conn!=null) conn.close(); + }catch(SQLException se){ + se.printStackTrace(); + } + } + } +} diff --git "a/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryTeacherByIdAndAge.java" "b/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryTeacherByIdAndAge.java" new file mode 100644 index 0000000..ca614db --- /dev/null +++ "b/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/QueryTeacherByIdAndAge.java" @@ -0,0 +1,56 @@ +package com.java.minxi.java_20240524.java_2302_王开社_2344310220; + +import java.sql.*; + +public class QueryTeacherByIdAndAge { + public static void main(String[] args) { + final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver"; + final String DB_URL = "jdbc:mysql://localhost:3306/student"; + + final String USER = "username"; + final String PASS = "password"; + + Connection conn = null; + PreparedStatement pstmt = null; + + try{ + Class.forName(JDBC_DRIVER); + + conn = DriverManager.getConnection(DB_URL,USER,PASS); + + String sql = "SELECT id, teacher_name, teacher_age FROM teacher_info WHERE id = ? AND teacher_age = ?"; + pstmt = conn.prepareStatement(sql); + pstmt.setInt(1, 1); + pstmt.setInt(2, 35); + ResultSet rs = pstmt.executeQuery(); + + while(rs.next()){ + int id = rs.getInt("id"); + String teacherName = rs.getString("teacher_name"); + int age = rs.getInt("teacher_age"); + + System.out.print("ID: " + id); + System.out.print(", 名称: " + teacherName); + System.out.println(", 年龄: " + age); + } + + rs.close(); + pstmt.close(); + conn.close(); + }catch(SQLException se){ + se.printStackTrace(); + }catch(Exception e){ + e.printStackTrace(); + }finally{ + try{ + if(pstmt!=null) pstmt.close(); + }catch(SQLException se2){ + } + try{ + if(conn!=null) conn.close(); + }catch(SQLException se){ + se.printStackTrace(); + } + } + } +} diff --git "a/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/UpdateTeacherName.java" "b/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/UpdateTeacherName.java" new file mode 100644 index 0000000..3779e0e --- /dev/null +++ "b/work/com/java/minxi/java_20240524/java_2302_\347\216\213\345\274\200\347\244\276_2344310220/UpdateTeacherName.java" @@ -0,0 +1,61 @@ +package com.java.minxi.java_20240524.java_2302_王开社_2344310220; + +import java.sql.Connection; +import java.sql.DriverManager; +import java.sql.PreparedStatement; +import java.sql.SQLException; + +public class UpdateTeacherName { + public static void main(String[] args) { + // JDBC 驱动名和数据库 URL + final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver"; + final String DB_URL = "jdbc:mysql://localhost:3306/student"; + + // 数据库用户名和密码 + final String USER = "username"; + final String PASS = "password"; + + Connection conn = null; + PreparedStatement pstmt = null; + + try { + // 注册 JDBC 驱动 + Class.forName(JDBC_DRIVER); + + // 打开连接 + conn = DriverManager.getConnection(DB_URL, USER, PASS); + + // 更新操作 + String sql = "UPDATE teacher_info SET teacher_name = ? WHERE id = ?"; + pstmt = conn.prepareStatement(sql); + pstmt.setString(1, "小严"); + pstmt.setInt(2, 3); + + int rowsAffected = pstmt.executeUpdate(); + if (rowsAffected > 0) { + System.out.println("执行成功"); + } + + // 清理环境 + pstmt.close(); + conn.close(); + } catch (SQLException se) { + // 处理 JDBC 错误 + se.printStackTrace(); + } catch (Exception e) { + // 处理 Class.forName 错误 + e.printStackTrace(); + } finally { + // 关闭资源 + try { + if (pstmt != null) pstmt.close(); + } catch (SQLException se2) { + } + try { + if (conn != null) conn.close(); + } catch (SQLException se) { + se.printStackTrace(); + } + } + } +} -- Gitee