Berechnete Felder in MySql
Wie kann ich berechnete Felder in einem MySql SELECT Ausdruck weiterverwenden?
ich habe:
<pre>
SELECTE tabelle.*,
IIF([Spalte1]='mitte',3,0) AS WertSpalte1,
WertSpalte1 * 2 AS DoppelterWert
FROM tabelle
</pre>
Stamms (author)
Author, followers, and translators associated with this PostIt.
| Thumbnail | Username | Role | Balance | Deadline | Emailed | Closed | |
|---|---|---|---|---|---|---|---|
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KAT Author | kathrin@nulllogic.de | Author | $0.00 | 2005-07-09 | Yes | Yes |
Codes (Descriptions)
| Comment | Status | Scanned | Receivers | |
|---|---|---|---|---|
| Code von KAT\ | - | No | 4 | view |
Angler (Matching)
| Angler | Status | Matched Time | Read Time | |
|---|---|---|---|---|
| Developer | - | 2014-10-24 22:35 | - | view |
| Kath & Comp | - | 2012-10-01 00:53 | - | view |
| ComputerMaus | - | 2005-06-29 03:08 | - | view |
| super supporterin | - | 2005-06-29 03:08 | - | view |
TopLabs (Answers)
| Thumbnail | TopLab | Author | Date | Reward |
|---|---|---|---|---|
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Siehe MySQL Referenzhandbuch 7.1.4
<pre>select @t1:=(@t2:=1)+@t3:=4,@t1,@t2,@t3; +----------------------+------+------+------+ | @t1:=(@t2:=1)+@t3:=4 | @t1 | @t2 | @t3 | +----------------------+------+------+------+ | 5 | 5 | 1 | 4 | +----------------------+------+------+------+ </pre> |
Frederic | 2005-06-29 | $0.93 |