Java implementation of mysql action class share Java connection to mysql

  • 2020-04-01 02:52:23
  • OfStack

Related software and drivers:
Mysql download version: 4.1.11
http://dev.mysql.com/downloads/mysql/4.1.html

JDBC driver download version: 3.1.8
http://dev.mysql.com/downloads/connector/j/3.1.html


 code 
Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->import java.sql.*;
public class mysql {
    public static String url = "jdbc:mysql://localhost:3306/test";//characterEncoding=GBK
    public static String username = "root";
    public static String password = "root";
    public static Connection con;
    public static Statement stmt;
    public static ResultSet rs;

    public static void main(String[] args) throws SQLException {
        connect();
        operation();
        stmt.close();
        con.close();
    }
    public static void test() {
        String sql_select = "select * from tablename where id=1";
        String sql_insert = "insert into tablename (col1,col2..) values('1','2'...)";
        String sql_update = "update tablename set colname='update' where id=1";
        //insert(sql_insert);
        //select(sql_select);
        //update(sql_update);
    }
    public static void connect() {
        //Locate driver
        try {
            Class.forName("com.mysql.jdbc.Driver");
            System.out.println(" Load drive successful !"); 
        } catch (ClassNotFoundException e) {
            System.out.println(" Load driver failed !");
            e.printStackTrace();
        }
        //Establish a connection
        try {
            con = DriverManager.getConnection(url, username, password);
            stmt = con.createStatement();
            System.out.println(" Database connection successful !"); 
        } catch(SQLException e) {
            System.out.println(" Database connection failed !"); 
        }
    }
    public static void select(String sql) {
        try {
            rs = stmt.executeQuery(sql);
            ResultSetMetaData meta_data = rs.getMetaData();//The column name
            for (int i_col = 1; i_col <= meta_data.getColumnCount(); i_col++) {
                System.out.print(meta_data.getColumnLabel(i_col) + "   ");
            }
            System.out.println();
            while (rs.next()) {
                for (int i_col = 1; i_col <= meta_data.getColumnCount(); i_col++) {
                    System.out.print(rs.getString(i_col) + "  ");
                }
                System.out.println();
            }
            rs.close();
        }catch (Exception e) {
            System.out.println(" Data query failed !");
        }
    }
    public static void insert(String sql) {
        try {
            stmt.clearBatch();
            stmt.addBatch(sql);
            stmt.executeBatch();
            System.out.println(" Data insertion successful !");
        }catch (Exception e) {
            System.out.println(" Data insertion failure !");
        }

    }
    public static void update(String sql) {
        try {
            stmt.executeUpdate(sql);
            System.out.println(" Data updated successfully !");
        }catch (Exception e) {
            System.out.println(" Data update failed !");
        }
    }
}


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