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Are there disadvantages to using a generic varchar(255) for all text-based fields?
...ould always store 255 characters.
But since you tagged this question with MySQL, I'll mention a MySQL-specific tip: as rows are copied from the storage engine layer to the SQL layer, VARCHAR fields are converted to CHAR to gain the advantage of working with fixed-width rows. So the strings in mem...
MySQL Results as comma separated list
...
The intent is fine and MySQL will allow this, but be careful (generally) with your use of GROUP BY. The items in the select list need to be valid aggregates in the context of the GROUP BY clause. In this case, p.name is not strictly valid. Any d...
Can you get DB username, pw, database name in Rails?
...%
require 'parseconfig'
c=ParseConfig.new('../../.my.cnf') %>
mysqlevn: &mysql
adapter: mysql
username: <%= c.params['client']['user'] %>
password: <%= c.params['client']['password'] %>
host: localhost
socket: <%= [
'/var/run/mysqld/mysqld.sock',
'/va...
Table is marked as crashed and should be repaired
...
Run this from your server's command line:
mysqlcheck --repair --all-databases
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How do I modify a MySQL column to allow NULL?
MySQL 5.0.45
6 Answers
6
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SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column
... Having a problem with a similar situation in PhpMyAdmin over MySQL. In my case, the source and destination columns are in the same table, but record selection is based on the other table. The "SELECT" version of the query works, but the UPDTATE statement throws a syntax error at "FRO...
How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
...
The fastest MySQL solution, without inner queries and without GROUP BY:
SELECT m.* -- get the row that contains the max value
FROM topten m -- "m" from "max"
LEFT JOIN topten b -- "b" from "...
How can I get the SQL of a PreparedStatement?
...
This also depends on the implementation. In MySQL -- at least the version I was using a few years ago -- the JDBC driver actually built a conventional SQL query from the template and bind variables. I guess that version of MySQL didn't support prepared statements nativ...
Upgrading PHP in XAMPP for Windows?
...
Take a backup of your htdocs and data folder (subfolder of MySQL folder), reinstall upgraded version and replace those folders.
Note:
In case you have changed config files like PHP (php.ini), Apache (httpd.conf) or any other, please take back up of those files as well and replace th...
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!";
}...