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MySQL: Insert record if not exists in table
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if you need to get warning message you can afterwards do mysql> show warnings\G
– fiorentinoing
Oct 20 '16 at 18:59
2
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How to generate .json file with PHP?
...t * from Posts limit 20";
$response = array();
$posts = array();
$result=mysql_query($sql);
while($row=mysql_fetch_array($result)) {
$title=$row['title'];
$url=$row['url'];
$posts[] = array('title'=> $title, 'url'=> $url);
}
$response['posts'] = $posts;
$fp = fopen('results.json...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...doesn't have to sort the output, and GROUP BY by default does. However, in MySQL even a DISTINCT+ORDER BY might still be faster than a GROUP BY due to the extra hints for the optimizer as explained by SquareCog.
– rustyx
Jan 25 '15 at 15:03
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Get table names using SELECT statement in MySQL
In MySQL, I know I can list the tables in a database with:
12 Answers
12
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Auto Generate Database Diagram MySQL [closed]
...elect specific tables and then create a database diagram for me based on a MySQL database? Preferably it would allow me to edit the diagram afterward since none of the foreign keys are set...
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How big can a MySQL database get before performance starts to degrade
At what point does a MySQL database start to lose performance?
15 Answers
15
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MySQL order by before group by
...pand on my comments about using a subquery to accurate return this data.
MySQL does not force you to GROUP BY every column that you include in the SELECT list. As a result, if you only GROUP BY one column but return 10 columns in total, there is no guarantee that the other column values which bel...
How to get UTF-8 working in Java webapps?
...s" those characters.
To get UTF-8 working under Java+Tomcat+Linux/Windows+Mysql requires the following:
Configuring Tomcat's server.xml
It's necessary to configure that the connector uses UTF-8 to encode url (GET request) parameters:
<Connector port="8080" maxHttpHeaderSize="8192"
maxThreads...
How do I add more members to my ENUM-type column in MySQL?
The MySQL reference manual does not provide a clearcut example on how to do this.
7 Answers
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log messages appearing twice with Python Logging
...g is left set to True. A
common scenario is to attach handlers only to the root logger, and to
let propagation take care of the rest.
So, if you want a custom handler on "test", and you don't want its messages also going to the root handler, the answer is simple: turn off its propagate flag:
logger...