How mysql converts data to mongodb

* ** Check whether the user name is registered * @ paramloginname * @ return * @ throwsSQLException * handle (Stringloginname) throwsSQLException {Stringsql & quot; selectcount (1) fromt_userwhereloginname? & Quot; Numbernumber (Number) qr. que mysqlmongodb

/**
* Check whether the user name is registered
* @ Param loginname
* @ Return
* @ Throws SQLException
*/
Public boolean ajaxValidateLoginname (String loginname) throws SQLException {
String SQL = "select count (1) from t_user where loginname =? ";
Number number = (Number) qr. query (SQL, new ScalarHandler (), loginname );
Return number. intValue () = 0;
}

/*** Check whether Email is registered * @ param email * @ return * @ throws SQLException */public boolean ajaxValidateEmail (String email) throws SQLException {String SQL = "select count (1) from t_user where email =? "; Number number Number = (Number) qr. query (SQL, new ScalarHandler (), email); return number. intValue () = 0;}/*** User name registration verification * @ param loginname * @ return */public boolean ajaxValidateLoginname (String loginname) {try {return userDao. ajaxValidateLoginname (loginname);} catch (SQLException e) {throw new RuntimeException (e );}} /*** Email verification * @ param email * @ return */public boolean ajaxValidateEmail (String email) {try {return userDao. ajaxValidateEmail (email);} catch (SQLException e) {throw new RuntimeException (e) ;}} this is written in mysql syntax. If mongo is used, how should I write it?