QBE Queries: Get Answers for RADL DB

[mathmari]

Hey! :giggle:

Give QBE-queries as for the RADL-database.
1. Give a QBE-expression that lists the names of the employees that accepted the orders from the company Maier Ingrid.
2. Give a QBE-expression that gives the order numbers for each individual customer.
3. Give a QBE-expression that lists all orders, the supervising employees and the total volume.I have done the following :

1. In SQL we had the query :

SELECT p.name
FROM personal p, auftrag a, kunde k
WHERE (p.persnr = a.persnr) AND (a.kundnr = k.nr) AND (k.name = 'Maier Ingrid')

So is the QBE-query then :

:unsure:2. Do we write :

Or do we need only the first table? Or do we need also a condition with GROUP BY in case that one costumer has more than one order?

:unsure:3. Do we do that as follows?

:unsure:

To check if we have the correct expressions can nwe check that somehow? Do we maybe write it inside "Afrage" ?

:unsure:

 

[I like Serena]

Hey mathmari!

Unfortunately I'm not familiar with QBE queries, and the wiki article does not seem to contain enough information. (Worried)

 

[mathmari]

Unfortunately I'm not familiar with QBE queries, and the wiki article does not seem to contain enough information. (Worried)

I uploaded https://docdro.id/G2SyjbL the notes that I am looking at. From page 39 (on the pdf from page 65) there is about QBE. As I understand it, we write on the tables the columns that we want and if there are specific conditions. :unsure:

 

[I like Serena]

I've examined your notes. And it seems that the variables you introduced should be preceded by an underscore.
So it should be for instance _PNR instead of PNR.

Additionally we should mark the fields that we are interested in by a keyword followed by a dot.
At this time I'm not entirely sure what they mean by a keyword, but by their examples it should be like "P.".
So for question 1 I think we should have "P." in the column "name" in the table personal.

 

[mathmari]

I've examined your notes. And it seems that the variables you introduced should be preceded by an underscore.
So it should be for instance _PNR instead of PNR.

Additionally we should mark the fields that we are interested in by a keyword followed by a dot.
At this time I'm not entirely sure what they mean by a keyword, but by their examples it should be like "P.".
So for question 1 I think we should have "P." in the column "name" in the table personal.

So do we have for question 1 :

and for question 3 :

? :unsure:At question 2 I noted now that the original statement is : "Geben Sie einen QBE-Ausdruck an, der die Auftragssummen je einzelnem Kunden ausgibt.". I thought that it were " Auftragsnummern" instead of " Auftragssummen". Can it be " Auftragssummen" ? Or is it a typo? Does it mean to count all orders or all costs of each costumer? Or is it a typo and we should give all order numbers? :unsure:

 

[I like Serena]

Looks about right. (Nod)

It makes sense to me to want to see the sum of the prices of all orders per customer. That would be the sum of all gesamtpreis'es per customer.

 

[mathmari]

It makes sense to me to want to see the sum of the prices of all orders per customer. That would be the sum of all gesamtpreis'es per customer.

So do we use the same tables as in question 3 ? Or do you mean an other gesamtpreis? :unsure:

 

[I like Serena]

So do we use the same tables as in question 3 ? Or do you mean an other gesamtpreis?

I think so yes.

And in question 3 we need the "total volume", which I'd actually interpret as the sum of all anzahls. :unsure:

 

[mathmari]

I think so yes.

And in question 3 we need the "total volume", which I'd actually interpret as the sum of all anzahls. :unsure:

So do we have have for question 2 :

and for question 3 :

? :unsure:

 

[I like Serena]

Looks about right to me. (Nod)