package database; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.swing.JOptionPane; public class Adduser { public static Boolean adduser(String user, String studentid, String name, String password) { Connection con = ConnectDatabase.connectDB(); PreparedStatement preSql; String sqlStr=null; if(userlist()) { sqlStr = "insert into usertable values (?,?,?,?,0)"; }else { sqlStr = "insert into usertable values (?,?,?,?,1)"; } try { preSql = con.prepareStatement(sqlStr); preSql.setString(1, user); preSql.setString(2, studentid); preSql.setString(3, name); preSql.setString(4, password); int ok = preSql.executeUpdate(); con.close(); return true; } catch (SQLException e) { JOptionPane.showMessageDialog(null, "用户名已存在", "警告", JOptionPane.WARNING_MESSAGE); return false; } } //判断用户是否存在 public static boolean userlist() { Connection con = ConnectDatabase.connectDB(); PreparedStatement preSql; ResultSet rs; String sqlStr = "select * from usertable"; try { preSql = con.prepareStatement(sqlStr); rs = preSql.executeQuery(); boolean flag = false; while(rs.next()) { flag = true; return true; } if(!flag) { return false; } con.close(); return false; } catch (SQLException e) { return false; } } }