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In SQL, what's the difference between count(column) and count(*)?
...a values(null,1)
insert #bla values(1,null)
insert #bla values(null,null)
select count(*),count(id),count(id2)
from #bla
results
7 3 2
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MySQL Data - Best way to implement paging?
...e LIMIT clause can be used to constrain the number of rows returned by the SELECT statement. LIMIT takes one or two numeric arguments, which must both be nonnegative integer constants (except when using prepared statements).
With two arguments, the first argument specifies the offset of the first ro...
IntelliJ - Convert a Java project/module into a Maven project/module
...
Right-click on the module, select "Add framework support...", and check the "Maven" technology.
(This also creates a pom.xml for you to modify.)
If you mean adding source repository elements, I think you need to do that manually–not sure.
Pre-Inte...
Is having an 'OR' in an INNER JOIN condition a bad idea?
... a MERGE JOIN.
It can be expressed as a concatenation of two resultsets:
SELECT *
FROM maintable m
JOIN othertable o
ON o.parentId = m.id
UNION
SELECT *
FROM maintable m
JOIN othertable o
ON o.id = m.parentId
, each of them being an equijoin, however, SQL Server's optimiz...
What is the fastest method for selecting descendant elements in jQuery?
As far is I know, there are a number of ways of selecting child elements in jQuery .
3 Answers
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Copying the GNU screen scrollback buffer to a file (extended hardcopy)
...e empty - it won't copy the entire scrollback buffer, just the portion you selected using Ctrl+A [
– Roshan
May 5 '11 at 20:33
...
How to filter logcat in Android Studio?
...ter on. Using this method you also save the filters and can re-use them by selecting them in the dropdown.
Screenshot:
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How to check existence of user-define table type in SQL Server 2008?
...y. You can't use OBJECT_ID to search for a table type by name -- check out SELECT name FROM sys.objects WHERE type = 'TT'
– NReilingh
Nov 29 '15 at 9:17
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How do I add a foreign key to an existing SQLite table?
...n step 8 below. One way to
do this is to run a query like the following: SELECT type, sql FROM
sqlite_master WHERE tbl_name='X'.
Use CREATE TABLE to construct a new table "new_X" that is in the
desired revised format of table X. Make sure that the name "new_X"
does not collide with any exi...
How can I add comments in MySQL?
...es of commenting are supported
Hash base single line commenting using #
Select * from users ; # this will list users
Double Dash commenting using --
Select * from users ; -- this will list users
Note : Its important to have single white space just after --
3) Multi line commenting using ...