MySQL-在两行的一列中显示来自两个表的数据

Question

My Problem is the following:

I have two tables with the same datatypes. One is called "rechnung" and one "rechnungarchiv".

Example row:

Rg_ID | Rg_KdID | Rg_Datum | Rg_Summe | Rg_AnzPos
DB5   |4711     |2010-etc. |2500.00   | 5

One table holds up-to-date data, the other one is an archive for old data. Now I have to display eg Rg_ID and RgAr_ID (two ID with the same format) in one column, but in two rows. This is my Query so far:

SELECT 
CONCAT(r.Rg_ID, a.RgAr_RgID) AS RechnungsID, 
CONCAT(r.Rg_KdID, a.RgAr_KdID) AS KundenID, 
CONCAT(r.Rg_Datum, a.RgAr_Datum) AS RechnungsDatum, 
CONCAT(r.Rg_Summe, a.RgAr_Summe) AS RechnungsSumme
FROM rechnung AS r
INNER JOIN rechnungarchiv AS a
ON r.Rg_KdID = a.RgAr_KdID

What I get is this:

DB5DB1  47114711    2010-06-03 00:00:002009-10-11 00:00:00  2500.00003725.0000

I simply want only data from one table at a time to be displayed. How do I do this?

Thanks in advance.

Answer 1

You're looking for the UNION operation:

SELECT 'rechnung' AS type, rechnung.*
  FROM rechnung
 UNION
SELECT 'archiv' AS type, rechnungarchiv.*
  FROM rechnungarchiv;

See this fiddle: http://sqlfiddle.com/#!9/04e31e/12