Category: Category: MySQL

Totalling column values with MySQL SUM The SUM() aggregate function calculates the total of values in a column. You […]

MySQL allows you to name the displayed columns. So instead of f_name or l_name etc. you can use more […]

The COUNT() aggregate functions counts and displays the total number of entries. For example, to count the total number […]

To list the average salary of employees in different departments (titles), we use the GROUP BY clause, as in: […]

The MySQL SELECT command is something like a print or write command of other languages. You can ask it […]

In addition to the four basic arithmetic operations addition (+), Subtraction (-), Multiplication (*) and Division (/), MySQL also […]

The SQL UPDATE command updates the data in tables. Its format is quite simple. UPDATE table_name SET column_name1 = […]

Till now we've dealt with text (varchar) and numbers (int) data types. To understand date type, we'll create one […]

Using Date to sort data select e_id, birth_date from employee_per ORDER BY birth_date; +——+————+ | e_id | birth_date | […]

The NULL column type is special in many ways. To insert a NULL value, just leave the column name […]