mysql.java

some java class and example

import java.sql.*;
import java.math.*;
//import org.gjt.mm.mysql.*;
public class Mysql {
    public static void main (String [] args) {
        String var1 = "abc";
        String var2 = "def";
        BigDecimal var3 = new BigDecimal("234.56");
                
        Connection con = null;
        Statement stmt = null;
        ResultSet rs = null;
        String sqlStmt = "";
        try {
            Class.forName("org.gjt.mm.mysql.Driver");
            con = DriverManager.getConnection ("jdbc:mysql://127.0.0.1:3306/test","","");
            stmt = con.createStatement();
            //For Insert Records
            sqlStmt = "insert into t1 values('"+var1+"','"+var2+"','"+var3.toString()+"')";
            stmt.executeUpdate(sqlStmt); 
            
            //stmt.executeUpdate("insert into t1 values('abc2','def','123.45')");
            
            //For Update Records                             
            //stmt.executeUpdate("update t1 set f2 = 'bbb' where f1='abc'");            
            
            //For Update Records                 
            //stmt.executeUpdate("delete from t1 where f1='abc'");
            
            //For Retrieve records
            sqlStmt = "select * from t1";
            rs = stmt.executeQuery(sqlStmt);
            while (rs.next()) {
                String a = rs.getString(1);        
                System.out.println(a);        
                System.out.println(rs.getString("F2"));
                BigDecimal c = (BigDecimal) rs.getBigDecimal("f3",2);
                System.out.println(c);
            }
        } catch(Exception e1) {
          System.out.println("Exception : "+e1);
        } finally {
            try {
                rs.close();
                stmt.close();       
                con.close();
            } catch (Exception e2) {
                System.out.println("Exception : "+e2);
            }
        }
    }
}

//mysql command;
//create table t1 (f1 varchar(10) primary key not null, f2 varchar(10),f3 numeric(10,2));