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Fastest way to count exact number of rows in a very large table?
I have come across articles that state that SELECT COUNT(*) FROM TABLE_NAME will be slow when the table has lots of rows and lots of columns.
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How do I check if a Sql server string is null or empty
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I think this:
SELECT
ISNULL(NULLIF(listing.Offer_Text, ''), company.Offer_Text) AS Offer_Text
FROM ...
is the most elegant solution.
And to break it down a bit in pseudo code:
// a) NULLIF:
if (listing.Offer_Text == '')
temp := nu...
SQL Server - Return value after INSERT
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No need for a separate SELECT...
INSERT INTO table (name)
OUTPUT Inserted.ID
VALUES('bob');
This works for non-IDENTITY columns (such as GUIDs) too
share
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What is a word boundary in regex?
...oundary, in most regex dialects, is a position between \w and \W (non-word char), or at the beginning or end of a string if it begins or ends (respectively) with a word character ([0-9A-Za-z_]).
So, in the string "-12", it would match before the 1 or after the 2. The dash is not a word character.
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Kill a postgresql session/connection
...user to use this function. This works on all operating systems the same.
SELECT
pg_terminate_backend(pid)
FROM
pg_stat_activity
WHERE
-- don't kill my own connection!
pid <> pg_backend_pid()
-- don't kill the connections to other databases
AND datname = 'database...
Force CloudFront distribution/file update
...Click on Blank Function (custom)
Step 3
Click on empty (stroked) box and select S3 from combo
Step 4
Select your Bucket (same as for CloudFront distribution)
Step 5
Set an Event Type to "Object Created (All)"
Step 6
Set Prefix and Suffix or leave it empty if you don't know what it is.
Step ...
“Inspect” a hover element?
...if this is just a problem on my PC or not, but I can't see the menu option selected via keyboard and the shortcut key (ctrl-shift-I) doesn't work while the dropdown menu is visible, so since inspect element is the last option on the dropdown, I used up-arrow key to wrap-around to the last item and h...
XPath: How to select elements based on their value?
...st thing is when using [], there are only two types of data:
[number] to select a node from node-set
[bool] to filter a node-set from node-set
In this case, the value is evaluated to boolean by function boolean(), and there is a rule:
Filters are always evaluated with respect to a context.
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How to select label for=“XYZ” in CSS?
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The selector would be label[for=email], so in CSS:
label[for=email]
{
/* ...definitions here... */
}
...or in JavaScript using the DOM:
var element = document.querySelector("label[for=email]");
...or in JavaScript using...
Get table name by constraint name [duplicate]
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SELECT owner, table_name
FROM dba_constraints
WHERE constraint_name = <<your constraint name>>
will give you the name of the table. If you don't have access to the DBA_CONSTRAINTS view, ALL_CONSTRAINTS or US...