Differend ID-column and display-column in QCombobox

Mr. Kibu

Hi,

I set a combo like this:

modItem=new QSqlTableModel(this);
modItem->setTable("vuVoucherPosItems");
modItem->select();

ui->cbItem->setModel(modItem);
ui->cbItem->setModelColumn(0);

But I want to display column 2 in the combobox not column 0 (but the value of column 0 should be stored in the corresponding TabelModel).
I know that there is a way using QSqlRelationTableModel and relations, but for different reasons I don't want to use it.

Is there a way to do this?

SGaist

Hi,

One way could be to use a QAbstractItemDelegate to change what is shown.

Out of curiosity, can you explain why you need that special setup ?

Mr. Kibu

Ok, I'll try:

I have got the field "ItemKey" in my parenttable. Here I want to store the ItemKey from a related Query (sqlite) with contains the fields ItemKey and ItemText (say OriginalItems to those Items). That's no problem.

But now I want to collect Items, that are not part of the related Query, and I don't want to store there, because they are very individual. The one possibility would be to store those values in an additional column (e.g. OtherItem). But now I have two imput-widgets (one combo and one lineedit) in my imput-form.

My idea:
Make an virtuall tabel (view) with the OtherItems (selected from the parenttable) and add them with a Union-Query to the related Query. In the fields "ItemKey" and "ItemText" of the OtherItems I have the same String (e.g. "abcde"), and in the fields "ItemKey" and "ItemText" of the OriginalItems I have the Key-Value and the corresponding Text-Value.
Now I want to display this in a combobox. This all will be no problem with an QSqlRelationalTabelModel and a relationship. But with this combobox I also want to add the new individuall items (OtherItems) and here I have got problems using QSqlRelationalTableNModel.
So, I thought it would be better to make it without relations, but here I have got the problem explained above.

conclusion:
I want to store the ItemKey from the related Query in the field "ItemKey" in my "parenttable" and display the ItemText (from the related Query) in the combobox. And I want to have the possibility to insert individuall Items in that combobox.

I hope, the explaination is not to confusing. What is the best way to do that?

Thank's a lot!!

SGaist

Well… I can't say it's really clear. Could you maybe make a picture of what you currently have and what you would like to get in the end ?

Mr. Kibu

I have got a table (sqlite) were I want to store item that I have buyed (=table "Purchase").
Some items (that I need in my database/programm for other calculations) are stored in a separate tabel (I will call them "StoredItems").
This table "StoredItems" have got the columns ItemKey and ItemText. My table "Purchase" contains a column called "ItemKey" were I can store this "StoredItem".

Now I want to have the possibility to store other individuall items, that are not stored in my database. The easiest way would be to add a column in "Purchase" called "OtherItem" and whrite here the items (just a string). In cases were I imput "StoredItems" in my table "Purchase" there will be a key-value in the column "ItemKey" and the column "OtherItem" will be NULL. On imput a "OtherItem" it will be reverse.
I think, that I need two imput widgets in my imput-form for this soulution (or is there an other (easy!!) way???).

So I wanted to combine the two possibilities in one column in the table "Purchase" (e.g. "Item"). If there is a "StoredItem" I will write the "ItemKey" from the related table "StoredItems" and if there is an "OtherItem" I will write the String for the other Item into this column.

For the combobox-model in the imput-form I would create a table that look like this:

ItemKey | ItemText

You see, that I would take the "OtherItems" and put it in the Key-column and in the text-column (I get the OtherItems from a query in my sqlite-database and add them to the "StoredItems" with an Union-query).

Here I want to link my imput-combobox with the column "Item" in the table "Purchcase" and display the value "ItemText" from the table above.

I know that it is a very complex construction, but I don't know how to do it better/easier. Is there a better solution, or how do I display the "ItemText" in my combobox.

Additon:
My above explained construction, will basicly operate with a QSqlRelationalTableModel (I have tried already).
But I also want to add new "OtherItems" with my combobox. On a relation with QSqlRelationTableModel I don't found a possibility to do this.

Thank you in advance for your patience!!!

SGaist

Shouldn't you rather have only one concept of item and then a qualifier ? e.g. a table ItemType which will contain e.g. Store and Other and in your Item table you'd have column which will be a foreign key (potentially with a unique constraint) on the ItemType table. That way you don't have to do funky logic to retrieve the items you are interested in, just standard queries/filers.

Mr. Kibu

I have already such a (working) solution. In the table "Purchase" I have the columns ItemKey, Item and ItemTyp. I map the column Item with my combobox and the data in the table "Purchase" will look like this:

ItemKey |Item |ItemTyp

If the imputed data in the combobox is a StoredItem, the ItemKey is written to the column "ItemKey" otherwise the column "ItemKey" is set NULL.
The column ItemKey in the table "Purchase" has got a foreign key constraint to the column ItemKey in the table "StoredItem".
But now I have to update the column "Item" in the table "Purchase" by myself if the data in the table "StoredItem" changes in the meanwhile.

SGaist

It shouldn't belong to the Purchase table. That table should only contain items whether they come from a store or somewhere else is not something that that table should handle.