SQL is a powerful language for managing and analyzing data in relational databases. One of its key features is the ability to perform advanced computations on the data using built-in functions. These functions allow you to manipulate the data in various ways, such as performing mathematical calculations, aggregating values, or extracting specific information from the data. In this blog post, we will explore some of the most commonly used built-in functions for advanced computations in SQL SELECT statements.

1. Mathematical Functions

SQL provides a wide range of mathematical functions that can be used to perform calculations on numeric data. These functions include:

ABS

The ABS function returns the absolute value of a number. It can be used to remove the sign of a negative number, or to return a positive value.

SELECT ABS(-5) AS absolute_value;

ROUND

The ROUND function rounds a numeric value to a specified number of decimal places.

SELECT ROUND(3.14159, 2) AS rounded_value;

SQRT

The SQRT function returns the square root of a numeric value.

SELECT SQRT(25) AS square_root;

2. Aggregation Functions

Aggregation functions are used to perform calculations on a set of values and return a single result. Some commonly used aggregation functions in SQL include:

SUM

The SUM function calculates the total sum of a column or a group of values.

SELECT SUM(price) AS total_price FROM products;

AVG

The AVG function calculates the average value of a column or a group of values.

SELECT AVG(quantity) AS average_quantity FROM orders;

COUNT

The COUNT function returns the number of rows in a table or the number of non-null values in a column.

SELECT COUNT(*) AS total_rows FROM customers;

3. String Functions

SQL provides various string functions that allow you to manipulate and extract information from strings. Some commonly used string functions include:

CONCAT

The CONCAT function is used to concatenate two or more strings together.

SELECT CONCAT(first_name, " ", last_name) AS full_name FROM employees;

SUBSTRING

The SUBSTRING function extracts a substring from a larger string based on a specified starting position and length.

SELECT SUBSTRING(description, 1, 10) AS excerpt FROM posts;

LENGTH

The LENGTH function returns the number of characters in a string.

SELECT LENGTH(email) AS email_length FROM users;

Conclusion

Using built-in functions in SQL SELECT statements allows you to perform advanced computations and manipulate data in various ways. Whether you need to perform mathematical calculations, aggregate values, or extract information from strings, SQL has a wide range of built-in functions to meet your needs. By leveraging these functions, you can enhance your data analysis capabilities and gain deeper insights from your database.

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