我在CMD里运行这个程序
import *;
import java.sql.*;

public class sqlBean{///

public Connection conn=null;

public ResultSet rs=null;

private String DatabaseDriver="sun.jdbc.odbc.JdbcOdbcDriver";
//DataSource 数据源名称DSN
private String DatabaseConnStr="jdbc:odbc:ClassDB2";

//定义方法
/*setXxx用于设置属性值;getXxx用于得到属性值*/
public void setDatabaseDriver(String Driver){
this.DatabaseDriver=Driver;
}
public String getDatabaseDriver(){
return (this.DatabaseDriver);
}

public void setDatabaseConnStr(String ConnStr){
this.DatabaseConnStr=ConnStr;
}
public String getDatabaseConnStr(){
return (this.DatabaseConnStr);
}

public sqlBean(){/////构造函数
try{


Class.forName(DatabaseDriver);
}
catch(java.lang.ClassNotFoundException e){
System.err.println("加载驱动器有错误:"+e.getMessage( ));
System.out.print("执行插入有错误:"+e.getMessage());//输出到客户端
}
}

                     
public int executeInsert(String sql){
int num=0;
try{
conn = DriverManager.getConnection("jdbc:odbc:ClassDB","limq","123");
Statement stmt=conn.createStatement( );
num=stmt.executeUpdate(sql);
}
catch(SQLException ex){
System.err.println("执行插入有错误:"+ex.getMessage() );
System.out.print("执行插入有错误:"+ex.getMessage());//输出到客户端
}

CloseDataBase();
return num;
}
// display data
 
public ResultSet executeQuery(String sql){
rs=null;
try{
conn = DriverManager.getConnection("jdbc:odbc:ClassDB","limq","123");
Statement stmt=conn.createStatement( );
rs=stmt.executeQuery(sql);
}
catch(SQLException ex){
System.err.println("执行查询有错误:"+ex.getMessage() );
System.out.print("执行查询有错误:"+ex.getMessage()); //输出到客户端
}

return rs;
}
// delete data
public int executeDelete(String sql){
int num=0;
try{

conn = DriverManager.getConnection("jdbc:odbc:ClassDB","limq","123");
Statement stmt=conn.createStatement( );
num=stmt.executeUpdate(sql);
}
catch(SQLException ex){
System.err.println("执行删除有错误:"+ex.getMessage() );
System.out.print("执行删除有错误:"+ex.getMessage()); //输出到客户端
}
CloseDataBase();
return num;
}
//////////////////
public void CloseDataBase(){
try{
conn.close();
}
catch(Exception end){
System.err.println("执行关闭Connection对象有错误："+end.getMessage( ) );
System.out.print("执行执行关闭Connection对象有错误：有错误:"+end.getMessage()); //输出到客户端
}
}
}
可出来的结果却是Exception in thread "main" java.lang.NoSuchMethodError: main
帮我看看是那出错了

不懂， 错误提示是没有main() 方法。

正如楼上所说 没main方法