retrieve a row of data from documentum via DQL

问题

I have a list of users in my list view which is populated by retrieving data from documentum . If I click on any row of this least (each row represent one user) I should be able to see all of their information listed down .(This is my problem )

public void selectedItemFromListView(){
     selected = lwAllUserGrp.getSelectionModel().getSelectedItem();
     System.out.println(selected);
     String query =" select * from dm_user where user_name = '@aclName'" ;
     String test = query.replace("@aclname", selected);

     GetDataWithDqlProfile(_session , query , "user_login_name" , "user_address" , "user_state" );
     System.out.println(user.getAddress());
     System.out.println(user.getState());
     System.out.println(user.getUsername());

}

if I click on a row of list view I can successfully see who is selected and I need to retrieve all the other attributes of that username (same person) from documentum via DQL .

private void GetDataWithDqlProfile(IDfSession session, String Query, String username , String address , String state ) {

    try {
        IDfQuery UpdateQuery = new DfQuery();
        UpdateQuery.setDQL(Query);
        IDfCollection col = UpdateQuery.execute(_session, IDfQuery.DF_QUERY);


            user.setAddress(col.getString(username));
            user.setUsername(col.getString(address));
            user.setState(col.getString(state));

        col.close();
    } catch (Exception e) {
        Alert alert = new Alert(Alert.AlertType.ERROR, e.getMessage());
        alert.showAndWait();
        Logs.WriteLog(LoginController.Repository + ",User:" + LoginController.Username, "DQL Query", e.toString());
        e.getStackTrace();
    }

and my output is :

User's name 
null
null 
null

I've tried the DQL query in DQL tester and it works well

回答1:

In order to fetch rows from IDfCollection you have to call next() on the collection object. This method both advances to the next row and returns a boolean if successful. Use a boolean test (e.g., while or if) to iterate, like this:

IDfCollection col = UpdateQuery.execute(_session, IDfQuery.DF_QUERY);

if (col.next()) {
    user.setAddress(col.getString(username));
    user.setUsername(col.getString(address));
    user.setState(col.getString(state));
}

col.close();

The iteration is necessary even if the collection contains only one row. In other words, you need to manually advance to the first row.

回答2:

1) As @eiviamu already mentioned, you have to call IDfCollection.next() to get the next row.
2) Your code, among other problems, has one documentum-related: closing of collection must happen always in finally block.
Otherwise you can get unclosed collection which might lead to memory leaks and weird application behavior (e.g. if I'm not mistaken there are 9 simultaneous open collections are allowed for one DCTM session by default, and if you exceed this limit an exception will be thrown)

回答3:

For those of you referring to this question later here is how I solved the problem :

public ArrayList<User> GetDataWithDqlpro(IDfSession session, String Query, String username , String state , String address) {

    try {
        IDfQuery UpdateQuery = new DfQuery();
        UpdateQuery.setDQL(Query);
        IDfCollection col = UpdateQuery.execute(_session, IDfQuery.DF_QUERY);

        while (col.next()) {
            list.add( new User(col.getString(username),col.getString(address) , col.getString(state)));

        }
        col.close();

    }catch (Exception e) {
            Alert alert = new Alert(Alert.AlertType.ERROR, e.getMessage());
            alert.showAndWait();
            Logs.WriteLog(LoginController.Repository + ",User:" + LoginController.Username, "DQL Query", e.toString());
            e.getStackTrace();
}
        return (ArrayList<User>) list;

}



public void selectedItemFromListView(){
     selected = lwAllUserGrp.getSelectionModel().getSelectedItem();
     System.out.println(selected);
     String Query = "select user_login_name , user_state , user_address from dm_user where user_login_name ='@aclname'";
     Query = Query.replace("@aclname",selected );
     ArrayList<User> allUserNames = GetDataWithDqlpro(_session, Query, "user_login_name","user_address","user_state");
     for (int i = 0 ; i <= allUserNames.size()-1 ; i++ ){
         if (selected.compareToIgnoreCase(allUserNames.get(i).getUsername() ) == 0){
                System.out.println(allUserNames.get(i).getState() );
                System.out.println(allUserNames.get(i).getAddress() );
                System.out.println(allUserNames.get(i).getUsername() );

         }

     }

}

Worth mentioning that I have a class called User with constructor and get and set methods

I hope it will help some one :)

来源：https://stackoverflow.com/questions/38891674/retrieve-a-row-of-data-from-documentum-via-dql

标签

javafx

dql

documentum