One column to multiple columns based on constraints?
| От | Davor J. |
|---|---|
| Тема | One column to multiple columns based on constraints? |
| Дата | |
| Msg-id | hkp8lk$2ls2$1@news.hub.org обсуждение исходный текст |
| Ответы |
R: One column to multiple columns based on constraints?
Re: One column to multiple columns based on constraints? |
| Список | pgsql-general |
Let's say you have a table: CREATE TABLE t ( time date, data integer ) Suppose you want a new table that has columns similar to the following: "(x.time, x.data, y.time, y.data, z.time, z.data)" where x.time, y.time and z.time columns are constrained (for example x.time >2007 AND x.time <2008, y.time >2008 AND y.time < 2009, z.time > 2010) How would you do this. Note that you can not use JOIN as there is no relationship. Currently I came up with something like this: SELECT X.*, (SELECT Y.time, Y.data FROM t AS Y WHERE Y.time = X.time + 1), (SELECT Z.time .) FROM t AS X WHERE X.time >2007 AND X.time <2008 But it's somewhat awkward. I thought maybe someone has better idea's. Any input is welcome.
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