Nice article about 10 SQL optimisations: MySQL, Oracle, SQL Server, DB2, PostgreSQL
Recently I found a very nice article explaining in great
MySQL
Learn MySQL by step by step tutorials, best practices and examples. How to install MySQL on Linux, How to change password of user, MySQL and Python, MySQL basics, Joins, CRUD operations, embedded selects, nested update queries, concatenation. MySQL diagrams, MySQL SSH setup, MySQL tools
Full back up, update and reinstall of MySQL Ubuntu 16
Back up MySQL manually or by script
Manual back up
Oracle, MySQL - select max and return multiple values
A common problems in SQL are to find the data
SQL concatenate examples
Concatenation basics
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concatenation functions:
* Oracle - concat
* MySQL - concat