Tag: mysql

Emptying a databases involves dropping (deleting) all its tables. The easiest way to do this is to drop and recreate a database: Depending on the system you are working, the…

If you don’t already have MySQL installed, install it with the following commands (mac only): Run the following commands to start or stop mysql. Start MySQL before proceeding: To see…

Character: set of symbols and encodings Encoding: set of values assigned to characters Collation: set of rule for comparing a character set Suppose you have the following characters, that are assigned the following values: sequentially.…

The Following SQL query will list all tables in a MySQL database and also list the row counts for each. where mydatabase is the name or your database. The output…

Emptying a databases involves dropping (deleting) all its tables. If you have a hundred tables in your database, the task becomes cumbersome. The easiest way to do this is to…

Problem: You are building a database and you have a field that can accept only certain responses. For example, there is a Gender column which accepts only M or F…

Oracle’s VirtualBox is a very solid and stable virtual machine but it isn’t the simplest to work with. So I abandoned it a week after I started working with. Recently,…

JavaScript Object Notation (JSON) is a lightweight standard for data interchange. It offers several advantages over XML for data interchange such as it can be used for serializing and transmitting…

Recently, I had to copy a large database from one server to another. I had 100G free on the source server. Unfortunately, the server would run out of memory before…

In the following query, we list all lastname held by 2 or more employees. If you want a value to be unique, you should add a unique constraint to the…