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How do you use script variables in psql?
...t myvariable value
... and can then be substituted, for example, as ...
SELECT * FROM :myvariable.table1;
... or ...
SELECT * FROM table1 WHERE :myvariable IS NULL;
edit: As of psql 9.1, variables can be expanded in quotes as in:
\set myvariable value
SELECT * FROM table1 WHERE column1 ...
Unioning two tables with different number of columns
...
Add extra columns as null for the table having less columns like
Select Col1, Col2, Col3, Col4, Col5 from Table1
Union
Select Col1, Col2, Col3, Null as Col4, Null as Col5 from Table2
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Get index of selected option with jQuery
I'm a little bit confused about how to get an index of a selected option from a HTML <select> item.
7 Answers
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How to determine the number of days in a month in SQL Server?
...er of days in the month.
DECLARE @ADate DATETIME
SET @ADate = GETDATE()
SELECT DAY(EOMONTH(@ADate)) AS DaysInMonth
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Convert a JSON string to object in Java ME?
...Node", "width":200, "height":100}
You can easily do so, without having to cast (keeping nimcap's comment in mind ;) ), with the following code:
Gson gson = new Gson();
final User user = gson.fromJson(jsonString, User.class);
Where jsonString is the above JSON String.
For more information, plea...
Retrieving the last record in each group - MySQL
...x, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;
Below is the original answer I wrote for this question in 2009:
I write the solu...
what is the difference between GROUP BY and ORDER BY in sql
... SUM, COUNT, AVG, etc).
TABLE:
ID NAME
1 Peter
2 John
3 Greg
4 Peter
SELECT *
FROM TABLE
ORDER BY NAME
=
3 Greg
2 John
1 Peter
4 Peter
SELECT Count(ID), NAME
FROM TABLE
GROUP BY NAME
=
1 Greg
1 John
2 Peter
SELECT NAME
FROM TABLE
GROUP BY NAME
HAVING Count(ID) > 1
=
Peter
...
Why doesn't java.util.Set have get(int index)?
...tem, I can
use set.iterator().next(), but
otherwise it seems I have to cast to
an Array to retrieve an item at a
specific index?
What are the appropriate ways of
retrieving data from a set? (other
than using an iterator)
You should also familiarise yourself with the SortedSet inte...
twitter bootstrap autocomplete dropdown / combobox with Knockoutjs
...
Have a look at Select2 for Bootstrap. It should be able to do everything you need.
Another good option is Selectize.js. It feels a bit more native to Bootstrap.
s...
Implement paging (skip / take) functionality with this query
...
In SQL Server 2012 it is very very easy
SELECT col1, col2, ...
FROM ...
WHERE ...
ORDER BY -- this is a MUST there must be ORDER BY statement
-- the paging comes here
OFFSET 10 ROWS -- skip 10 rows
FETCH NEXT 10 ROWS ONLY; -- take 10 rows
If we want...