After i have removed some log entries in a SQLite DB, I found that the database file size stay the same. This is because SQLite will keep the used space and reuse them later.
We can use the VACUUM command to release the empty space.
sqlite3 <your_sqlite_db_file> "VACUUM;"
Assume the table has a column called CREATED_DATE which stores the creation date. The following SQL make use of the DATEADD() function to select records which are created within the recent 10 days.
CREATED_DATE > DATEADD(day, -10, getdate())
We can use different unit in the datepart (The first argument in DATEADD()) as stated in the 2nd reference link below.
After i reboot my OS X, i find that i couldn’t start the MySQL server and it throws the following error:
hatuey:5.6.19 yingkityuen$ mysql.server start
. ERROR! The server quit without updating PID file (/usr/local/var/mysql/hatuey.local.pid).
Go to the above folder and delete the mysql error log which is ended with .err. In my case, i executed the following command:
hatuey:5.6.19 yingkityuen$ rm /usr/local/var/mysql/hatuey.local.err
Where hatuey is my Mac machine name.
This should fix the problem.
Reference: Mahdi Yusuf – MySQL ‘The server quit without updating PID file’
1. Deactivate the virtualenv if there is.
2. Install the required libraries.
sudo apt-get install libpq-dev python-dev
3. Install PostgreSQL.
sudo apt-get install postgresql postgresql-contrib
Continue reading Install and setup PostgreSQL for Django
There is a timezone configuration on PostgreSQL server. If you want to change the default globally, you can edit the postgresql.conf. On Ubuntu, it is located at
# - Locale and Formatting -
datestyle = 'iso, mdy'
#intervalstyle = 'postgres'
#timezone = 'Hongkong'
timezone = 'UTC'
We could also tweak the timezone only in your current PostgreSQL session.
1. Get the current timezone.
Continue reading PostgreSQL – Set and Get Timezone
1. Start the meteor app.
2. Open another shell and connect to the app database which is also called meteor.
- mongo 127.0.0.1:3001/meteor
3. Check if you could find the collections there.
Run the following SQL to get the info of the installed SQL Server.
Continue reading Check if the MSSQL Server is 32-bit or 64-bit
If you have problem on importing the SQL in phpMyAdmin. First, try increasing the following two values in php.ini.
Second, Add the following line in the phpMyAdmin config.inc.php.
$cfg['ExecTimeLimit'] = 0;
Reference: Best way to import large .sql files to PHPmyAdmin via WAMP
Access To MySQL is a freeware which help converting the data in .mdb in Microsoft Access to .sql in MySQL. Check this out.
Bullzip – Access To MySQL
1. Download and install Access To MySQL.
2. Run the Access To MySQL.
Continue reading Export Microsoft Access .mdb to MySQL
Use the following SQL to list out all database users in MySQL.
select host, user from mysql.user;
Reference: Alvin Alexander – MySQL show users – how to show the users in a MySQL database