SQL/MySQL How to query 3 tables with or wihtout a join You can query more than 2 tables with SQL. Below John D K Sep 13, 2018 2 min read
JIRA how to format code python, SQL, Java You have two options of formatting code in JIRA: * using John D K Aug 16, 2018 1 min read
MySQL create, alter and drop table, DB In previous posts we saw some DML(Data Manipulation Language) John D K Mar 22, 2018 1 min read
MySQL coalesce, exists, union and having example Working with SQL requires formatting and filtering of data which John D K Mar 21, 2018 2 min read
MySQL update, insert, delete examples In this post we will cover the rest of the John D K Mar 15, 2018 1 min read
SQL select aggregate functions examples In this post we will cover most used SQL select John D K Mar 14, 2018 1 min read
SQL select examples This is part of tutorial learning SQL from beginners in John D K Mar 13, 2018 1 min read
mysql join simple example for beginners SQL join are explained by Venn diagrams. Venn diagrams are John D K Feb 27, 2018 3 min read
Oracle count null and not null values in column In this article we will post two ways of counting John D K Feb 23, 2018 1 min read
MySQL 5.7 show table columns 3 ways 1 Show MySQL table columns by describe The simplest and John D K Feb 22, 2018 1 min read
MySQL 5.7 alter table add column Adding new table is most common DDL operation that I'm John D K Feb 22, 2018 1 min read
MySQL update embedded select Simple example of update using nested query or in other John D K Feb 6, 2018 1 min read
MySQL 8 embedded update over several tables MySQL update one table embedded select UPDATE table1 t1, ( SELECT John D K Dec 21, 2017 1 min read
Nice article about 10 SQL optimisations: MySQL, Oracle, SQL Server, DB2, PostgreSQL Recently I found a very nice article explaining in great John D K Oct 2, 2017 1 min read
Full back up, update and reinstall of MySQL Ubuntu 16 Back up MySQL manually or by script Manual back up John D K Sep 2, 2017 2 min read
Oracle, MySQL - select max and return multiple values A common problems in SQL are to find the data John D K Aug 31, 2017 5 min read
Oracle indexes - create, rebuild, select, drop Select all indexes by status Check indexes by status by John D K Aug 30, 2017 3 min read
SQL concatenate examples Concatenation basics * concatenation functions: * Oracle - concat * MySQL - concat John D K Aug 29, 2017 1 min read
Frequent SQL commands DML and DDL Frequent SQL commands part 2 Data manipulatiuon language DML -- John D K Jul 6, 2017 1 min read
Frequent SQL commands select Frequent SQL commands This is my SQL cheat-sheet for MYSQL. John D K Jul 5, 2017 3 min read