SQL Server Full Course for Data Analyst | Day 12 | User Defined Functions | Scalar vs Table Function

Описание: This video focuses on User Defined Functions (UDFs) in SQL Server, explaining how to create, use, and apply them in real-world scenarios. It covers the concept, types, syntax, and practical benefits of UDFs, showing how they help in code reusability, cleaner queries, and advanced data analysis.
The session is especially useful for SQL learners, database developers, and data analysts who want to write modular, reusable, and efficient SQL code.

Timeline Summary

00:00 – 02:45: Introduction to Functions in SQL Server
Explanation of built-in functions (string, mathematical, date & time) and the concept of user defined functions. The importance of using UDFs for data cleaning and manipulation is introduced.

02:45 – 06:15: Functions With and Without Parameters
Difference between functions that accept parameters and those that do not, with clear examples and use cases.

06:15 – 09:15: Scalar vs Table Valued Functions
Introduction to scalar functions (return a single value) and table valued functions (return a table as output).

09:15 – 17:00: Creating a Basic User Defined Function
Step-by-step explanation of UDF syntax with a simple greeting function and how to execute it in SQL Server.

17:00 – 26:50: Parameterized Functions and CONCAT Example
Building functions that accept inputs, generating dynamic output using parameters, and using string functions like CONCAT.

26:50 – 35:50: Using User Defined Functions Across Databases
Demonstration of how a UDF created in one database can be accessed and used in another database in SQL Server.

35:50 – 46:55: Table Valued Function Syntax and Usage
Creating a table valued function that returns filtered data based on input parameters and understanding how to call it using SELECT statements.

46:55 – 55:30: Statistical Analysis Using Functions
Building functions to calculate minimum, maximum, average, count, and other statistical values for analytical reporting.

55:30 – 01:12:00: Temporary Tables and Final Concepts
Using temporary tables within functions to improve readability and structure for statistical and summary reports, followed by a recap of key concepts.

Key Takeaways

User Defined Functions can be parameterized or non-parameterized.

Functions return results in two forms: Scalar (single value) or Table Valued (table output).

UDFs promote code reusability and cleaner SQL queries.

Built-in functions like CONCAT can be used inside UDFs.

Table Valued Functions are called using SELECT * FROM function_name() syntax.

SQL Server supports table-returning functions, which are not available in MySQL.

Temporary tables help in statistical analysis and structured reporting.

UDFs make complex logic easier to manage and maintain in large SQL projects.

Frequently Asked Questions (FAQs)

Q1: What is a User Defined Function in SQL Server?
A User Defined Function is a custom function created by the user to perform specific data processing tasks.

Q2: What is the difference between scalar and table valued functions?
Scalar functions return a single value, while table valued functions return a complete table as output.

Q3: Can a user defined function be used in another database?
Yes, SQL Server allows UDFs to be called across databases.

Q4: Why are temporary tables used in functions?
Temporary tables help store intermediate results and simplify statistical or summary reporting.

Q5: Are table valued functions available in MySQL?
No, MySQL does not support table valued functions; similar behavior is achieved using stored procedures.

Conclusion

This session provides a complete understanding of User Defined Functions in SQL Server, including their types, syntax, and real-world applications. UDFs help developers write modular, reusable, and efficient SQL code, especially for complex data manipulation and analysis tasks.
By mastering scalar and table valued functions, learners can significantly improve their SQL programming skills and prepare for advanced topics like stored procedures, triggers, and enterprise-level SQL development.

#SQLServer
#SQLDay12
#UserDefinedFunction
#UDFinSQL
#SQLFunctions
#ScalarFunction
#TableValuedFunction
#SQLServerTutorial
#LearnSQL
#SQLForBeginners
#SQLDeveloper
#SQLInterviewQuestions
#SQLForDataAnalyst
#DatabaseDevelopment
#TSQL
#SQLProgramming
#DataAnalytics
#CodingAnalyticsWithAnkit