basicdao.java

来自「C语言小型分析器实验报告1） 待分析的简化C语言的词法说明； 2） 单词符号的」· Java 代码 · 共 61 行

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class BasicDao {
	private Connection conn;
	private Statement st;
	private ResultSet result;
	public BasicDao(){

	}
	
	public Connection getConnection(){
		try {
			Class.forName("com.mysql.jdbc.Driver");
			String url = "jdbc:mysql://localhost:3306/student?user=root&password=jake";
			conn = DriverManager.getConnection(url);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return conn;
	}
	
	public ResultSet queryString(String sql) throws SQLException{
		if(null == conn || conn.isClosed()){
			conn = getConnection();
		}
		st = conn.createStatement();
		result = st.executeQuery(sql);
		return result;
	}
	
	public int executeString(String sql) throws SQLException{
		if(null == conn || conn.isClosed()){
			conn = getConnection();
		}
		st = conn.createStatement();
		return st.executeUpdate(sql);
	}
	
	public void closeAll(){
		try {
			if(null != result)
				result.close();
			if(null != st)
				st.close();
			if(null != conn)
				conn.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
}