Java-JDBC (java realizes the addition, deletion, modification, and batch processing in the database)

JDBC operation database

Remarks: To undertake java-JDBC (connect to the database) blog post
1. First of all, create a data table

in the database 2. Add data to the database in java

• First define a method in the interface

 //添加信息
public int AddUser(UserInfo ui);

//修改信息
public int UpdateUser(UserInfo ui);

//删除信息
public int deleteUser(int id);

// 批处理添加数据
public int [] addBatchUser(List<UserInfo> list);

Then add a method to the implementation class of the interface

//添加信息
@Override
public int AddUser(UserInfo ui) {
    
    
    //数据库连接对象
    Connection conn = DBtest.getConn();
    String sql = "insert into emp values(?,?,?,?,?,?,?,?)";
    int result = 0;
    try {
    
    
        PreparedStatement ps = conn.prepareStatement(sql);
        ps.setInt(1,ui.getEmpno());
        ps.setString(2,ui.getEname());
        ps.setString(3,ui.getJob());
        ps.setInt(4,ui.getMgr());
        ps.setString(5,ui.getHiredate());
        ps.setInt(6,ui.getSal());
        ps.setInt(7,ui.getComm());
        ps.setInt(8,ui.getDeptno());

        result = ps.executeUpdate();

    } catch (SQLException e) {
    
    
        e.printStackTrace();
    }
    return result;
}

//更新数据
@Override
public int UpdateUser(UserInfo ui) {
    
    
    //数据库连接对象
    Connection conn = DBtest.getConn();
    String sql = "update emp set ename=?,job=?,mgr=?,hiredate=?,sal=?,comm=?,deptno=? where empno = ?";
    int result = 0;
    try {
    
    
        PreparedStatement ps=conn.prepareStatement(sql);

        ps.setString(1,ui.getEname());
        ps.setString(2,ui.getJob());
        ps.setInt(3,ui.getMgr());
        ps.setString(4,ui.getHiredate());
        ps.setInt(5,ui.getSal());
        ps.setInt(6,ui.getComm());
        ps.setInt(7,ui.getDeptno());
        ps.setInt(8,ui.getEmpno());
        result = ps.executeUpdate();
    } catch (SQLException e) {
    
    
        e.printStackTrace();
    }
    return result;
}

//删除信息
@Override
public int deleteUser(int id) {
    
    
    int result = 0;
    Connection conn = DBtest.getConn();
    String sql = "delete  from emp Where empno = ?";
    try {
    
    
        PreparedStatement pps = conn.prepareStatement(sql);
        pps.setInt(1,id);
        result = pps.executeUpdate();
    } catch (SQLException e) {
    
    
        e.printStackTrace();
    }
    return result;
}

//批处理
@Override
public int[] addBatchUser(List<UserInfo> list) {
    
    
    Connection conn = DBtest.getConn();
    int [] result = null;
    try {
    
    
        conn.setAutoCommit(false);
        String sql = "insert into emp value(?,?,?,?,?,?,?,?)";
        //预编译语句
        PreparedStatement pps = conn.prepareStatement(sql);
        Iterator<UserInfo> iter = list.iterator();
        while (iter.hasNext()){
    
    
            UserInfo ui = iter.next();
            pps.setInt(1,ui.getEmpno());
            pps.setString(2,ui.getEname());
            pps.setString(3,ui.getJob());
            pps.setInt(4,ui.getMgr());
            pps.setString(5,ui.getHiredate());
            pps.setInt(6,ui.getSal());
            pps.setInt(7,ui.getComm());
            pps.setInt(8,ui.getDeptno());
            pps.addBatch();
        }
        result = pps.executeBatch();
        conn.commit();
    } catch (SQLException e) {
    
    
        e.printStackTrace();
    }
    return new int[0];
}