| From: | LALIT KUMAR <lalit(dot)jss(at)gmail(dot)com> |
|---|---|
| To: | pgsql-novice(at)postgresql(dot)org |
| Subject: | compare date in two rows |
| Date: | 2011-06-17 10:17:43 |
| Message-ID: | BANLkTi=gZbJW7+bNHPQnTPRPNnMGC2UucA@mail.gmail.com |
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| Lists: | pgsql-novice |
Hi,
I have a table with following sample data.
Village_name Date Label
A 1991-01-31 0
A 1991-04-28 0
A 1991-07-15 0
B 2000-02-15 0
B 2000-04-13 0
B 2001-09-13 0
C 1995-07-12 0
C 1995-10-13 0
I need to update the label to 1 when the number of days between two
dates(when compared with previous date) is greater than 120 for each
village.
Illustration:
For village A: row 1 date will not be compared to any date.
row 2 date will be compared to row 1 date and if
satisfies the condition label will be made 1.
row 3 compare to row 2 and continue this till last row
for village A.
Similarly first date for village B,C.
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| Next Message | Oliveiros d'Azevedo Cristina | 2011-06-17 11:10:33 | Re: compare date in two rows |
| Previous Message | Jean-Yves F. Barbier | 2011-06-17 07:56:43 | change p/w hashing |