how do I find a primary key using a QSqlRelationalTableModel?

jdent

if all I have is a QSqlRelationalTableModel, and want to retrieve a record with primary key X, how can I do it?

Regards,
Juan Dent

Christian Ehrlicher

@jdent said in how do I find a primary key using a QSqlRelationalTableModel?:

how can I do it?

By looking in the documentation and finding QSqlTableModel::primaryKey()

jdent

@Christian-Ehrlicher No I wasn't clear. I know what the primary key of a table is. I need to find a record in that table with primary key == 5, for instance, using the model QSqlRelationalTableModel.
I can always do a loop:

	int located_row = -1;
	for( int row =0; row < model->rowCount(); ++row)
	{
		auto id = model->record(row).value(0).toInt();
		if(id == 2)
		{
			located_row = row;
			break;
		}
	}

but there must be a method!

JonB

@jdent
You have to iterate through the rows looking for the value you want.
If you use a QSortFilterProxyModel you can take advantage of binary search for speed if you sort by primary key. QSqlRelationalTableModel is not important here, all that gives is a "lookup" on one field to map e.g. an integer value to a corresponding string from a related table for display.