• JDBC 操作mysql 实现增删查改


    package com.eduk.demo;

    import com.mysql.jdbc.Connection;
    import com.mysql.jdbc.PreparedStatement;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;


    public class JDBCOperation {
        private static  Connection conn = null;//声明数据库回话对象,Connection 这是用来维护数据库连接信息
        private static  Statement sts = null;// Statement   用来操作数据,也是执行SQL语句(父类)
        
        
        static class Student {
            private String Id;
            private String Name;
            private String Sex;
            private String Age;
            private String Course;
            private String Time;

           Student(String Id, String Name, String Sex, String Age,String Course,String Time) {
                this.Id = Id; //default
                this.Name = Name;
                this.Sex = Sex;
                this.Age = Age;
                this.Course = Course;
                this.Time = Time;
            }

            public String getCourse() {
                return Course;
            }

            public void setCourse(String course) {
                Course = course;
            }

            public String getTime() {
                return Time;
            }

            public void setTime(String time) {
                Time = time;
            }

            public void setAge(String age) {
                Age = age;
            }

            public String getId() {
                return Id;
            }

            public void setId(String Id) {
                this.Id = Id;
            }

            public String getName() {
                return Name;
            }

            public void setName(String Name) {
                this.Name = Name;
            }

            public String getSex() {
                return Sex;
            }

            public void setSex(String Sex) {
                this.Sex = Sex;
            }

            public String getAge() {
                return Age;
            }

            public void setage(String Age) {
                this.Age = Age;
            }
    }
        
        
        private static Connection getConn() {
            String driver = "com.mysql.jdbc.Driver";
            String url = "jdbc:mysql://localhost:3306/uus";
            String username = "root";
            String password = "root";
            Connection conn = null;
            try {
                Class.forName(driver); //classLoader,加载对应驱动
                conn = (Connection) DriverManager.getConnection(url, username, password);
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            return conn;
        }
        
        
        
        private static int CreateDatabase(String database) {
            Connection conn = getConn();
            int i = 0;
            String sql = "CREATE DATABASE "+database;
            //String sql = "DROP DATABASE "+database;
            PreparedStatement pstmt;
            try {
                pstmt = (PreparedStatement) conn.prepareStatement(sql);
                i = pstmt.executeUpdate();
                System.out.println("resutl: " + i);
                System.out.println("创建数据库" + database + "成功!");
                pstmt.close();
                conn.close();
            } catch (SQLException e) {
                System.out.println("创建数据表失败!");
                e.printStackTrace();
            }
            return i;
        }
        
        
        
        private static int CreateTable() {
            Connection conn = getConn();
            int i = 0;
            //        UPDATE students set age="23" where name="Achilles";
            //        UPDATE users SET age = 24, name = 'Mike' WHERE id = 123;
              String sql = "CREATE TABLE student " +
              "(sid INTEGER(20) not NULL, " +
              " name VARCHAR(255) not NULL, " +
              " sex VARCHAR(255), " +
              " age INTEGER(4), " +
              " course FLOAT(8), " +
              " time VARCHAR(32), " +
              " PRIMARY KEY ( sid ))ENGINE=InnoDB DEFAULT CHARSET=UTF8; ";
           // String sql = "update student set name='" + student.getName() + "' where sid=" + student.getId();
            //String sql = "update student set name='送终极' where sid=12;";
                try {

                    sts = conn.createStatement();//初始化statement
                    int f = sts.executeUpdate(sql);
            
                    System.out.println("创建数据表成功!");
                } catch (SQLException e) {
                    System.out.println("创建数据表失败!");
                    e.printStackTrace();
                }
                finally {
                    try {
                    //    res.close();//可写可不写
                        sts.close();//可写可不写
                        conn.close();//一定要写
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
                return 0;
        }
        
        
        
        private static int insert(Student student) {
            Connection conn = getConn();
            int i = 0;
            String sql = "insert into student (SID,Name,Sex,Age,Course,Time) values(?,?,?,?,?,?)";
            PreparedStatement pstmt;
            try {
                pstmt = (PreparedStatement) conn.prepareStatement(sql);
                pstmt.setString(1, student.getId());
                pstmt.setString(2, student.getName());
                pstmt.setString(3, student.getSex());
                pstmt.setString(4, student.getAge());
                pstmt.setString(5, student.getCourse());
                pstmt.setString(6, student.getTime());
                i = pstmt.executeUpdate();
                pstmt.close();
                conn.close();
                System.out.println("插入成功!");
            } catch (SQLException e) {
                System.out.println("插入失败!");
                e.printStackTrace();
            }
            return i;
        }
        
        
        private static int update(Student student) {
            Connection conn = getConn();
            int i = 0;
            //        UPDATE students set age="23" where name="Achilles";
            //        UPDATE users SET age = 24, name = 'Mike' WHERE id = 123;
           String sql = "update student set Name='" + student.getName() + "',sex='" + student.getSex() + "', age = '" +
            student.getAge() + "',course = '" + student.getCourse() + "', time = '" + student.getTime()   + "' where sid='" + student.getId() + "'";
           // String sql = "update student set name='" + student.getName() + "' where sid=" + student.getId();
            //String sql = "update student set name='送终极' where sid=12;";
            PreparedStatement pstmt;
            try {
                pstmt = (PreparedStatement) conn.prepareStatement(sql);
                i = pstmt.executeUpdate();
                System.out.println("resutl: " + i);
                pstmt.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            return i;
        }

        
        private static Integer getAll() {
            Connection conn = getConn();
            String sql = "select * from student order by sid desc";
            PreparedStatement pstmt;
            try {
                pstmt = (PreparedStatement)conn.prepareStatement(sql);
                ResultSet rs = pstmt.executeQuery();
                int col = rs.getMetaData().getColumnCount();
                System.out.println("============================");
                while (rs.next()) {
                    for (int i = 1; i <= col; i++) {
                        System.out.print(rs.getString(i) + " ");
                        if ((i == 2) && (rs.getString(i).length() < 8)) {
                            System.out.print(" ");
                        }
                     }
                    System.out.println("");
                }
                    System.out.println("============================");
            } catch (SQLException e) {
                e.printStackTrace();
            }
            return null;
        }
        
        
        private static int delete(String name) {
            Connection conn = getConn();
            int i = 0;
            String sql = "delete from students where Name='" + name + "'";
            PreparedStatement pstmt;
            try {
                pstmt = (PreparedStatement) conn.prepareStatement(sql);
                i = pstmt.executeUpdate();
                System.out.println("resutl: " + i);
                pstmt.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            return i;
        }
        
        
        
        
        
        public static void main(String args[]) {
        //    JDBCOperation.CreateDatabase("uus");
        //    JDBCOperation.CreateTable();
            JDBCOperation.insert(new Student("8","阳春白雪", "女", "23","95",""));
           // JDBCOperation.getAll();
          //  JDBCOperation.update(new Student("12","JAC", "Femail","26", "90",""));
         //   JDBCOperation.update(new Student("4","欧阳春","男","29", "90",""));
           // JDBCOperation.delete("Achilles");
            JDBCOperation.getAll();
        }
    }

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  • 原文地址:https://www.cnblogs.com/youxianyen/p/5646731.html
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