大约有 42,000 项符合查询结果(耗时:0.0342秒) [XML]
MySQL JOIN the most recent row only?
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For anyone who must work with an older version of MySQL (pre-5.0 ish) you are unable to do sub-queries for this type of query. Here is the solution I was able to do and it seemed to work great.
SELECT MAX(d.id), d2.*, CONCAT(title,' ',forename,' ',surname) AS name
FROM cust...
Windows: XAMPP vs WampServer vs EasyPHP vs alternative [closed]
...o, but I want to open it up further to include all possible Windows/Apache/MySQL/PHP stacks.
5 Answers
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How do I check if an index exists on a table field in MySQL?
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Use SHOW INDEX like so:
SHOW INDEX FROM [tablename]
Docs: https://dev.mysql.com/doc/refman/5.0/en/show-index.html
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MySQL - How to select data by string length
Is there a MySQL function to do this (of course instead of string_length )?
6 Answers
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Is it possible to roll back CREATE TABLE and ALTER TABLE statements in major SQL databases?
...tive.
Is DDL transactional according to this document?
PostgreSQL - yes
MySQL - no; DDL causes an implicit commit
Oracle Database 11g Release 2 and above - by default, no, but an alternative called edition-based redefinition exists
Older versions of Oracle - no; DDL causes an implicit commit
SQL ...
Can a C# class inherit attributes from its interface?
...e = typeof(T);
return type.GetCustomAttributes(attributeType, true).
Union(type.GetInterfaces().
SelectMany(interfaceType => interfaceType.GetCustomAttributes(attributeType, true))).
Distinct().Cast<T>();
}
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How to check if field is null or empty in MySQL?
...uld like to check in PHP , then you should do something like :
$query_s =mysql_query("SELECT YOURROWNAME from `YOURTABLENAME` where name = $name");
$ertom=mysql_fetch_array($query_s);
if ('' !== $ertom['YOURROWNAME']) {
//do your action
echo "It was filled";
} else {
echo "it was empty!";
}...
How do I modify a MySQL column to allow NULL?
MySQL 5.0.45
6 Answers
6
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What does character set and collation mean exactly?
I can read the MySQL documentation and it's pretty clear. But, how does one decide which character set to use? On what data does collation have an effect?
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How to get next/previous record in MySQL?
...ding that a primary key colum is not meant as a column to sort by, because MySQL does not guarantee that higher, auto incremented, values are necessarily added at a later time.
If you don't care about this, and simply need the record with a higher (or lower) id then this will suffice. Just don't us...
