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How do MySQL indexes work?
I am really interested in how MySQL indexes work, more specifically, how can they return the data requested without scanning the entire table?
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What is cardinality in MySQL?
What is cardinality in MySQL? Please explain in simple, non-technical language.
8 Answers
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In php, is 0 treated as empty?
...sset($var) && $var != 0){ Do Something} ??
– mysqllearner
Feb 8 '10 at 9:22
1
@mysql For ...
“21天教你学会C++” - 创意 - 清泛网 - 专注C/C++及内核技术
...法（如果你已经会一门类似的语言），但你无法学到多少如何运用这些语法。简而言之，如果你是，比如说一个Basic程序员，你可以学会用C++语法写出Basic风格的程序，但你学不到C++真正的优点（和缺点）。那关键在哪里？Alan Per...
Is there a Max function in SQL Server that takes two values like Math.Max in .NET?
...he "best answer" because:
It doesn't require complicating your code with UNION's, PIVOT's,
UNPIVOT's, UDF's, and crazy-long CASE statments.
It isn't plagued with the problem of handling nulls, it handles them just fine.
It's easy to swap out the "MAX" with "MIN", "AVG", or "SUM". You can use any ...
Which MySQL datatype to use for an IP address? [duplicate]
...on and inet_ntop for conversion:
'INSERT INTO `table` (`ipv6`) VALUES ("'.mysqli_real_escape_string(inet_pton('2001:4860:a005::68')).'")'
'SELECT `ipv6` FROM `table`'
$ipv6 = inet_pton($row['ipv6']);
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Difference between two dates in MySQL
... value can range from "-838:59:59" to "838:59:59". w3schools.com/SQl/func_mysql_timediff.asp
– cREcker
Aug 3 '17 at 12:21
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How to escape apostrophe (') in MySql?
The MySQL documentation says that it should be \' . However, both scite and mysql shows that '' works. I saw that and it works. What should I do?
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MySQL query String contains
I've been trying to figure out how I can make a query with MySQL that checks if the value (string $haystack ) in a certain column contains certain data (string $needle ), like this:
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Get table column names in MySQL?
Is there a way to grab the columns name of a table in mysql?
using php
19 Answers
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