The following are just examples of the use date offsets;
SET @timeframe=now()-interval 2 year;
SELECT ...
WHERE o.doe >= @timeframe
SET @timeframe = DATE_SUB(CURDATE(), interval 1 day);
SELECT ...
WHERE o.doe >= @timeframe and o.doe <= @timeframe
The former will deal with the full date/time stamp, while the latter will consider only the date and is good for when we need to find results for a particular day for example.
This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)
When using Visual Studio (recent versions), with vdproj files, you may get an error or warning that the file is incompatible or unable to open.
-eq
is equal to
if [ "$a" -eq "$b" ]
-ne
is not equal to
if [ "$a" -ne "$b" ]
-gt
is greater than
if [ "$a" -gt "$b" ]
-ge
is greater than or equal to
if [ "$a" -ge "$b" ]
-lt
is less than
if [ "$a" -lt "$b" ]
-le
is less than or equal to
if [ "$a" -le "$b" ]
==
is equal to
if [ "$a" == "$b" ]
!=
is not equal to
if [ "$a" != "$b" ]
[source]
Detecting the screen size in php, is not something that can be done with php alone but the following is what I use to kind of get around it.
SELECT AUTO_INCREMENT as 'next_id' FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'db_name' AND TABLE_NAME = 'table_name';
Following a recent change to GitHub, username and passwords would no longer work with Netbeans and others when interacting with repositories. Other IDE's such as Jetbrains are able to use Tokens but Netbeans proved to be a little more stubborn.
Continuous data is data obtained by measurement whereas discrete data is data obtained by counting.
To mount a vhd file under Linux (tested with Debian buster), firstly get the following;
A reminder...
Any networking services should be handles by rc.init2 and simply requires making the appropriate script in /etc/rc.d executable.
But if we add our own custom script, then we can add the following to rc.local
# Start MCR Monitor
if [ -x /etc/rc.d/rc.mcr_monitor ]; then
echo "Starting MCR Monitor..."
. /etc/rc.d/rc.mcr_monitor start
fi
Generally to use sed, we would do;
sed -i 's/old-text/new-text/g' file.txt
where file.txt is the file containing old-text and new-text.
If we want to ensure that our search term is at the beginning of the line, we add the ^ as follows;
sed -i 's/^old-text/new-text/g' file.txt
Use the following to provide debugging information while developing in visual Studio;
System.Diagnostics.Debug.WriteLine("something of interest...");
Issue: Application that should not have been running had been started using monit and then stopped using monit.
I go this error while trying to configure gnucobol but I have seen it before somewhere, just cant for the life of me remember where. anyway, a solution is to install the following;
libdb-dev
If we want to save the output from a MySQL session to a file, we can do this by adding the following to the end of the query;
INTO OUTFILE '/tmp/myresults.csv';
To execute a shell command from php, typically do the following;
<?php
$output = shell_exec('sudo -u root monit summary');
echo "<pre>$output</pre>";
?>
In the above scenario, we want to run something as root, so we need to modify our /etc/sudoers file;
Firstly, assuming the user is www-data then we can add the following line to /etc/sudoers
www-data ALL = NOPASSWD: /usr/sbin/monit
where /usr/sbin/monit is the command that we wish to allow the user www-data to run without the need to enter a password.
This works on Slackware
Create or edit your /home/user/.vimrc file, adding the following;
:set background = dark
If we have an svn url which we backup and restore to a new url, then we can update existing source to point to the new url as below;
If we want to ensure that we are always running the most recent version of a script, then we can use curl as below;
curl -s http://192.168.254.198/stuff/scripts/myscript.sh | bash -s arg1 arg2 arg3
where http://192.168.254.198/stuff/scripts/myscript.sh is the location of the script, reachable from the target machine and arg1, arg2, arg3 are optional parameters that would be applicable if the script was run from the command line as ./myscript.sh arg1 arg2 arg3
tunefs -l name /dev/sda1
where name is the name we wish to use and /dev/sda1 is the target partition.
ALT + [LEFT SHIFT] + [NUM LOCK]
Then we can use the cursor keys or mouse keys with ENTER being a LEFT CLICK
To open Chrome with Developer Tools all the time, you simply open in with the following arguments;
--args --auto-open-devtools-for-tabs
To have this done in PhpStorm goto Tools>Web Browsers and edit Chrome, adding in the above to the Command Line Options field.
If we've deleted or messed up a configuration file, then we can restore by doing the following;
If we want to read an option group within a my.cnf config file for MySQL, then we can do so as follows;
my_print_defaults --config-file=/etc/mysql/my.cnf mysqld2
The following works quite well;
my_print_defaults mysqld1
this will read from all configuration files (assuming they are included), where mysqld1 is the group
Resources;
https://dev.mysql.com/doc/refman/8.0/en/multiple-servers.html
https://mariadb.com/kb/en/running-multiple-mariadb-server-processes/#systemd
https://www.percona.com/blog/2014/08/26/mysqld_multi-how-to-run-multiple-instances-of-mysql/
Master-Slave
https://www.toptal.com/mysql/mysql-master-slave-replication-tutorial this one rocks
https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-in-mysql
See also https://stackoverflow.com/a/2896718
and my previous post here
For an overview of Replication specific Filters, see here https://mydbops.wordpress.com/2021/09/24/replication-filters-in-mysql-an-overview/
See here for copies of my 3 cnf files from a working configuration on a Slackware box.
I had trouble building mesllink using Netbeans but note that it did build correctly from the original source on the box, from the command line by running make.
This is similar to a problem I had with mesdb detailed here. (worth reading first).
