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postgres default timezone
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Choose a timezone from:
SELECT * FROM pg_timezone_names;
And set as below given example:
ALTER DATABASE postgres SET timezone TO 'Europe/Berlin';
Use your DB name in place of postgres in above statement.
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How do you count the number of occurrences of a certain substring in a SQL varchar?
...mparing the lengths
Declare @string varchar(1000)
Set @string = 'a,b,c,d'
select len(@string) - len(replace(@string, ',', ''))
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Convert string[] to int[] in one line of code using LINQ
...you would need the extra ToArray call to get an array:
int[] myInts = arr.Select(int.Parse).ToArray();
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Generating a UUID in Postgres for Insert statement?
...d to run psql -d dbname -f SHAREDIR/contrib/module.sql and now it works!!! select uuid_generate_v1(); returns 1 now now. Thanks so much!
– anon58192932
Sep 29 '12 at 22:13
5
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Inner join vs Where
... for the query using the inner join:
-- with inner join
EXPLAIN PLAN FOR
SELECT * FROM table1 t1
INNER JOIN table2 t2 ON t1.id = t2.id;
SELECT *
FROM TABLE (DBMS_XPLAN.DISPLAY);
-- 0 select statement
-- 1 hash join (access("T1"."ID"="T2"."ID"))
-- 2 table access full table1
-- 3 table access ful...
Eclipse copy/paste entire line keyboard shortcut
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Ctrl-Alt-Down: copies current line or selected lines to below
Ctrl-Alt-Up:: copies current line or selected lines to above
Ctrl-Shift-L: brings up a List of shortcut keys
See Windows/Preference->General->Keys.
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How to create your own library for Android development to be used in every program you write?
...uide focuses on creating Android libraries.
Give your library a name and select a minimum SDK version for the code in the library, then click Finish.
Once the Gradle project sync completes, the library module appears in
the Project panel on the left. If you don't see the new module
fol...
Comparing date ranges
... range_start, here's some simple SQL to retrieve all the matching rows:
SELECT *
FROM periods
WHERE NOT (range_start > @check_period_end
OR range_end < @check_period_start)
Note the NOT in there. Since the two simple rules finds all the non-matching rows, a simple NOT will reve...
How to check if field is null or empty in MySQL?
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Either use
SELECT IF(field1 IS NULL or field1 = '', 'empty', field1) as field1
from tablename
or
SELECT case when field1 IS NULL or field1 = ''
then 'empty'
else field1
end as field1
from tablename
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how to check the dtype of a column in python pandas
...know this is a bit of an old thread but with pandas 19.02, you can do:
df.select_dtypes(include=['float64']).apply(your_function)
df.select_dtypes(exclude=['string','object']).apply(your_other_function)
http://pandas.pydata.org/pandas-docs/version/0.19.2/generated/pandas.DataFrame.select_dtypes.h...