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Select data from date range between two dates
I have a table Named Product_Sales and it holds data like this
19 Answers
19
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What's wrong with nullable columns in composite primary keys?
...keys is not clean relational database design.
If there are two entities A and B where A can optionally be related to B, the clean solution is to create a resolution table (let's say AB). That table would link A with B: If there is a relationship then it would contain a record, if there isn't then i...
INSERT IF NOT EXISTS ELSE UPDATE?
... the ID column: In the replacement case the statement would set it to NULL and then a fresh ID would be allocated.
This approach can also be used if you want to leave particular field values alone if the row in the replacement case but set the field to NULL in the insert case.
For example, assumin...
The definitive guide to form-based website authentication [closed]
...tion. The sections below will deal with patterns for sound practical auth, and how to avoid the most common security pitfalls.
To HTTPS or not to HTTPS?
Unless the connection is already secure (that is, tunneled through HTTPS using SSL/TLS), your login form values will be sent in cleartext, which al...
What XML parser should I use in C++? [closed]
I have XML documents that I need to parse and/or I need to build XML documents and write them to text (either files or memory). Since the C++ standard library does not have a library for this, what should I use?
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How can I remove a character from a string using Javascript?
...ing.replace(/\/r/g, '/');
EDIT:
Since everyone's having so much fun here and user1293504 doesn't seem to be coming back any time soon to answer clarifying questions, here's a method to remove the Nth character from a string:
String.prototype.removeCharAt = function (i) {
var tmp = this.split(...
How can I sort arrays and data in PHP?
... sorts low-to-high or reverse ("r"), whether it sorts values or keys ("k") and how it compares values ("nat" vs. normal). See http://php.net/manual/en/array.sorting.php for an overview and links to further details.
Multi dimensional arrays, including arrays of objects
$array = array(
array('foo'...
What are the pros and cons of performing calculations in sql vs. in your application
...ed to access/aggregate a lot of data, doing it at the db server will save bandwidth, and disk io if the aggregates can be done inside indexes)
convenience (sql is not the best language for complex work - especially not great for procedural work, but very good for set-based work; lousy error-handling...
How to randomize (or permute) a dataframe rowwise and columnwise?
...,]
> df2
a b c
3 0 1 0
4 0 0 0
2 1 0 0
1 1 1 0
By default sample() randomly reorders the elements passed as the first argument. This means that the default size is the size of the passed array. Passing parameter replace=FALSE (the default) to sample(...) ensures that sampling is done withou...
WatiN or Selenium? [closed]
... tests of our presentation soon. It seems that everyone recommends WatiN and Selenium . Which do you prefer for automated testing of ASP.NET web forms? Which of these products work better for you?
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