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How to get the max of two values in MySQL?
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Use GREATEST()
E.g.:
SELECT GREATEST(2,1);
Note: Whenever if any single value contains null at that time this function always returns null (Thanks to user @sanghavi7)
s...
MySQL join with where clause
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You need to put it in the join clause, not the where:
SELECT *
FROM categories
LEFT JOIN user_category_subscriptions ON
user_category_subscriptions.category_id = categories.category_id
and user_category_subscriptions.user_id =1
See, with an inner join, putting a claus...
In Ruby on Rails, what's the difference between DateTime, Timestamp, Time and Date?
...ave DATE, DATETIME, TIME and TIMESTAMP column data types; just as you have CHAR, VARCHAR, FLOAT and INTEGER.
So, you ask, what's the difference? Well, some of them are self-explanatory. DATE only stores a date, TIME only stores a time of day, while DATETIME stores both.
The difference between DATE...
SQL standard to escape column names?
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For MySQL, use back ticks `.
For instance:
SELECT `column`, `column2` FROM `table`
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Converting PKCS#12 certificate into PEM using OpenSSL
...the above example, I get the following: "TypeError: initializer for ctype 'char' must be a bytes of length 1, not str" Is there something wrong with my password
– getaglow
Nov 29 '18 at 15:29
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How to use the “required” attribute with a “radio” input field
...buttons they must all have the same name value. This allows only one to be selected at a time and applies required to the whole group.
<form>
Select Gender:<br>
<label>
<input type="radio" name="gender" value="male" required>
Male
</label><b...
NoClassDefFoundError - Eclipse and Android
...t; Java Build Path -> "Order and Export" (it was listed before, but not selected)
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What is a “batch”, and why is GO used?
...add a column to a table, then it should be in its own batch.
If you try to SELECT the new column in the same batch it fails because at parse/compile time the column does not exist.
GO is used by the SQL tools to work this out from one script: it is not a SQL keyword and is not recognised by the eng...
What is the difference between square brackets and parentheses in a regex?
...nt, you would code (?:7|8|9) to make it a non capturing group.
[abc] is a "character class" that means "any character from a,b or c" (a character class may use ranges, e.g. [a-d] = [abcd])
The reason these regexes are similar is that a character class is a shorthand for an "or" (but only for singl...
What is the difference between localStorage, sessionStorage, session and cookies?
...e Mozilla source code we can see that 5120KB (5MB which equals 2.5 Million chars on Chrome) is the default storage size for an entire domain. This gives you considerably more space to work with than a typical 4KB cookie.
The data is not sent back to the server for every HTTP request (HTML, images, J...