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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 ('' !== $ertom['YOURROWNAME']) {
//do your action
echo "It was filled";
} else {
echo "it was empty!";
}...
那些我印象深刻的建议和教诲 - 杂谈 - 清泛网 - 专注C/C++及内核技术
...负有心人”和“蠢”之间可能连窗户纸都没有，只看个人如何面对了。
多用Google吧
我工作的第一天，项目经理把我叫去说：给你们讲讲JUnit, SVN，Ant, JBuilder的用法，明天开始用。这四样东西我以前都没有接触过，第一反应就是...
Get top n records for each group of grouped results
...g this: The version is the variables is close to being correct. However, MySQL does not guarantee the order of evaluation of expressions in the SELECT (and, in fact, sometimes evaluates them out-of-order). The key to the solution is to put all the variable assignments in a single expression; here...
How do I check if an index exists on a table field in MySQL?
...
Use SHOW INDEX like so:
SHOW INDEX FROM [tablename]
Docs: https://dev.mysql.com/doc/refman/5.0/en/show-index.html
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Windows: XAMPP vs WampServer vs EasyPHP vs alternative [closed]
...o, but I want to open it up further to include all possible Windows/Apache/MySQL/PHP stacks.
5 Answers
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MySQL JOIN the most recent row only?
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For anyone who must work with an older version of MySQL (pre-5.0 ish) you are unable to do sub-queries for this type of query. Here is the solution I was able to do and it seemed to work great.
SELECT MAX(d.id), d2.*, CONCAT(title,' ',forename,' ',surname) AS name
FROM cust...
Is it possible to roll back CREATE TABLE and ALTER TABLE statements in major SQL databases?
...tive.
Is DDL transactional according to this document?
PostgreSQL - yes
MySQL - no; DDL causes an implicit commit
Oracle Database 11g Release 2 and above - by default, no, but an alternative called edition-based redefinition exists
Older versions of Oracle - no; DDL causes an implicit commit
SQL ...
Best Practices: Salting & peppering passwords?
...e that someone with some security experience supports this method. Would a MySQL AES_ENCRYPT($passwordHash, $serverSideKey) call also be an appropriate way of implementing this?
– foochow
Jun 27 '13 at 19:40
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MySQL CONCAT returns NULL if any field contain NULL
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mysql has IFNULL(arg, default) instead COALESCE with the same syntax
– Vasilii Suricov
Feb 19 '19 at 17:58
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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...