idea连接数据库步骤详解

package com.company;
import java.sql.*;
public class Main {public static void main(String[] args) {Student student = new Student();try {SqlOperation.main();ResultSet resultSet = ScoreSql.selectScoreSql();//输出所有行操作while(resultSet.next()){System.out.println(resultSet.getString("name"));System.out.println(resultSet.getFloat("score"));}}catch(Exception e) {e.printStackTrace();System.out.println("连接数据库失败！");}}SqlOperation.close();
}

连接数据库并创建操作对象

package com.company;import java.sql.*;public class SqlOperation {public static Connection connection = null;//定义连接数据库的对象（桥梁）public static String url = "jdbc:sqlserver://localhost:1433;DatabaseName=Studentinfo";public static Statement statement = null;//定义静态操作对象public static PreparedStatement preparedStatement = null;//定义动态操作对象public static void main() {try{//第一步加载驱动Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");System.out.println("加载驱动成功！");//第二步建立连接connection = DriverManager.getConnection(url,"sa","shejiashuai");System.out.println("连接数据库成功！");//第三步建立操作对象statement = connection.createStatement();}catch (Exception e){e.printStackTrace();System.out.println("连接数据库失败！");}}public static void close(){//关闭对象try{statement.close();connection.close();}catch (Exception e){e.printStackTrace();}}
}

package com.company;import java.sql.ResultSet;
//创建操作成绩数据库的类
class ScoreSql {public static ResultSet selectScoreSql()throws Exception{return SqlOperation.statement.executeQuery("select * from Score");//调用SqlOperation.statement并使用其函数}public static void insertScoreSql(Score score)throws Exception{SqlOperation.statement.executeUpdate("insert into Score values ("+score.getName()+","+score.getScore()+")");}public static void createScoreSql()throws Exception{SqlOperation.statement.executeUpdate("create table Score(name char(10),score float)");}public static void deleteScoreSql(String name)throws Exception{SqlOperation.statement.executeUpdate("delete from Score where name = " +name);}public static void updateScoreSql(Score score)throws Exception{SqlOperation.statement.executeUpdate("update Score set score = " +score.getScore() + "where name = " +score.getName());}public static void statisticScoreSql(float score)throws Exception{//统计大于此分数的人SqlOperation.statement.executeUpdate("select * from Score where score > " +score);}
}
//下面是成绩类可省略不看
public class Score{String name;float score;public void setName(String name) {this.name = name;}public void setScore(float score) {this.score = score;}public String getName() {return name;}public float getScore() {return score;}
}

package com.company;import java.sql.ResultSet;class StudentSql{public static ResultSet selectStudentSql()throws Exception{return SqlOperation.statement.executeQuery("select * from Student where age > 18");}
}
//下面是学生类可省略不看
public class Student{private String name;private String sex;private String age;public String getName() {return name;}public String getSex() {return sex;}public String getAge() {return age;}public void setName(String name) {this.name = name;}public void setSex(String sex) {this.sex = sex;}public void setAge(String age) {this.age = age;}
}