Compare values from columns of multiple tables. This query can be used to compare two tables in such manner in postgres.
A database is a system intended to organize, store, and retrieve large amounts of data easily.
25 Mar, 2020
This snippet shows you how you can copy a whole table to another one. Useful if you are about to change data in a table and later need to compare it with EXCEPT.
28 Nov, 2019
When you have primary keys generated by the database not by the application, then you might need it to be returned. In postgres you have to use RETURNING function in your sql query in order to have...
6 Jul, 2019
Installing mssql server on Arch Linux is actually quite simple.
20 Feb, 2019
This snippet shows how to create a new database and user with assigning permissions of the newly created database to the user. In this example I use database name as user name for clarity and...
15 Aug, 2018
There are actually two ways of updating in MySQL. This example uses the simpler way. Other way is to define columns and corresponding values sepparately.
16 May, 2018
To insert multiple rows with a single query you can use regular insert with multiple value rows. You can also use update if you have primary key set.
16 May, 2018
Import csv file to MySQL, the fastest way is to use a direct import with query. You have to have the columns created the way you need.
8 May, 2018
Example query for direct csv saving from mysql. Using query to import or export data is the fastest method. You can export your query results as csv with custom syntax. You have to use union to join...
1 Jun, 2017
Got an error while trying to update the system "mtop: installing libmariadbclient (10.1.24-1) breaks dependency 'libmysqlclient'". The package 'libmariadbclient' dropped its provide for '...
27 Jan, 2017
From version 5.7 MySQL stops supporting zeros value in date / datetime. If you have those values in your database you get errors for queries, like group by. Also you are not able to insert zero dates...
21 Sep, 2016
If you need to show user different content whether a table is empty or not. So you would need to count table rows for that. Counting every row will iterate through the table rows and is really slow....
25 Apr, 2016
Group by date when using datetime datatype. In this snippet the grouping is used to pull out monthly statistics. The query is pretty much self explanatory. Group by in mysql can help you to bring...
6 Oct, 2015
Have you ever had to do bigger mysql import? If you do, you probably get annoyed by not being able to know how long it will take to complete. There is a command called "pv". Basically it allows a...
5 Dec, 2014
MySQL configuration that I am using for developing Drupal in localhost. The config file can be found from /etc/mysql/my.cnf under Linux. I would use it for any apache instance tough. You might get...
14 Mar, 2014
Using this the query in this snippet enables you to convert character set to utf8. This works in mysql or mysql like database, drop-in databases like mariadb for an example.
9 Nov, 2013
Snippet showing, how to do string replace in MySQL. In this example we update a field with the same field content except we run it through string replace. This is the same as find...
8 Nov, 2013
This snippet shows you how to drop all tables from database in mysql. Unsing drop database will just delete the database and later you just recreate it with create database query.
22 Jul, 2013
Full guide for MySQL joins. Visual data and query examples should make the subject perfectly clear or you can bookmark it as a good reference. So here it is, the visual representation of sql (mysql)...
15 Jul, 2013
How to import .sql file in MySQL through command line.
15 Jul, 2013
Want to check the databases you have created using the MySQL Command Line Client? Use mysql command to connect to mysql server and list available databases.
10 Jul, 2013
This snippet shows you how to select discinct first letters of titles. After getting the first letters you might want to transliterate the characters, you can do it in mysql by custom function where...
5 May, 2013
Sometimes when you import lines from txt files you might get \r in the end of lines. When you think it's easier to remove trailing carriage returns than reimporting then you can use this query.
21 Mar, 2013
If you have a lot of content with timestamps, you might want to get all the years where the content belongs. For an example created. With this query you can get years when some content was created.
3 Jan, 2013
The MySQL command line client provides you with a means of interacting with your MySQL server from the command line. Open terminal window to connect to MySQL server also you may have to do that via...
17 Feb, 2012
Get MSSQL column information. It includes column data type, lenght, name etc...
14 Dec, 2011
How to get MySQL columns data of a table in PHP. The data includes name, type, null allowed or not, key, default value and extra for auto_increase and such.
24 May, 2011
How to delete all rows of MySQL table. With reseting primary key auto increment and without reseting it.
8 May, 2011
How to turn MySQL query into an array in PHP. Print query results on screen. This is useful for determining contents of a table.
6 May, 2011
This query example shows how to delete rows older than x amount of minutes, hours, days, months or even years. This is a part of MySQL date and time functions.