sqlstatment.java

java开发的大整数计算器,实现基本的运算,还有sin,cos,tan,cot.

import java.sql.*;

public class SqlStatment
{
	private Connection con;

	public SqlStatment()
	{
		con = new DBConnect().getConnection("config.bin");

	}

	public int RegistUser(String userName,String userPsw)
	{
		String registString = "SELECT * FROM UserInfo WHERE uesrName = '" + userName + "'";
		
		String addString = "INSERT INTO UserInfo VALUES(?,?)";

		Statement registStat;

		try
		{
			registStat = con.createStatement();

			ResultSet registResu = registStat.executeQuery(registString);

			if(registResu.next())
			{
				return -1;
			}
		}
		catch(SQLException e)
		{
			e.printStackTrace();
		}
		
		PreparedStatement coursePreStat;

		try
		{
			coursePreStat = con.prepareStatement(addString);

			coursePreStat.setString(1,userName);
			coursePreStat.setString(2,userPsw);

			coursePreStat.executeUpdate();

			coursePreStat.close();

			con.commit();
		}
		catch(SQLException e)
		{
			System.err.print(e.getMessage());
		}
		
		
		return 0;
	}
	
	public int CheckUser(String userName,String userPsw)
	{
		String checkString = "SELECT * FROM UserInfo WHERE uesrName = '" + userName + "'";
		
		Statement checkStat;

		try
		{
			checkStat = con.createStatement();

			ResultSet checkResu = checkStat.executeQuery(checkString);

			if(!checkResu.next())
			{
				return -1;
			}
			else if(checkResu.getString("userPsw").equals(userPsw));
			{
				return 0;
			}
		}
		catch(SQLException e)
		{
			e.printStackTrace();
		}
		return -1;
	}
}