MySQL Functions - Function Examples Tutorial

Practice Using String Functions

Write a query that concatenates first and last names, converts the result to uppercase, and trims any extra spaces.

Expected output: A column showing uppercase full names without leading or trailing spaces.

Hint: Use CONCAT(), UPPER(), and TRIM() functions together.

Calculate Average Salary

Write a query to calculate the average salary of employees in each department.

Expected output: A list of departments with their average salaries.

Hint: Use AVG() with GROUP BY department_id.

Format Dates

Write a query that shows the hire date formatted as 'Month Day, Year' (e.g., January 1, 2020).

Expected output: A column with formatted hire dates.

Hint: Use DATE_FORMAT() with appropriate format specifiers.

String functions operate on individual string values to manipulate text, while aggregate functions perform calculations on multiple rows and return a single summarized value.

CONCAT() joins two or more strings into one continuous string. If any argument is NULL, it returns NULL unless CONCAT_WS() is used.

Using functions on indexed columns can prevent MySQL from using the index efficiently, leading to slower query performance.