Blog

How to Use Functions in SQL

In today’s world, data is everything, and every major organisation survives on data. With the correct data and information, they can take a significant decision, whether it is financial or operational.

Thus the importance of Database management is enormous in today’s world & which is why engineers learn SQL and need Programming Homework help. If you are one of those who are looking for SQL queries, assignments & others, go through this blog post, where we will discuss SQL Functions.

What is SQL & its function?

SQL is a type of programming language that helps in managing the relational database & also performs different types of functions within data in the database.

Note: Relational databases are databases that include columns, rows & tables. For example, any business with a database includes tables describing the phone number, address, name and other details.

In terms of use, it is used in the following cases:

  • Helps in modifying the database table
  • It is also used in index structures.
  • Help in updating, adding & deleting rows of data.
  • It was also retrieving various types of information within different database management systems. Such information is used for multiple things like analytics applications, transaction processing & applications that require communication within the relational database. Get Programming Assignment Help to understand it more.

The queries of SQL & its function take the shape of commands which are noted as statements & are divided into programs that allow the users to modify & change the data from the tables & rows in a particular database.

In this database, a table is the unit of a particular database that consists of different columns & rows of data. A table in the database has many records & each record is stored in a row of the particular table. Tables are the most used types of objects in the data, which hold enormous data. Get Programming Homework Help to know it better.

There are other types of database objects as well. Some of these are given below:

  • Views represent data in the logical form assembled from different types of databases.
  • Indexes are lookup tables that increase the speed of lookup functions in a particular database.
  • Reports are used to recover from more than one table.

So, we already understand SQL and its function; now, let’s talk about its type & position in the database.

Types of Function in SQL Server

A function is a set of SQL statements that performs a special type of task. Functions help in the reusability of the code. If you are writing large SQL scripts for performing the same type of action, then you can create a function for it.

So, next time there is no need to rewrite the SQL query or command. You need to call that function. It accepts the input command in the form of parameters & returns the value. It also comes with an inbuilt function that performs a variety of tasks. In the SQL Server, there are two types of operations. Let’s define these functions one by one:

1. Scalar Defined Function:

All the functions in the SQL server are defined for different purposes. These functions which are determined by the system are called “Scalar defined functions”. Using this function SQL can save much of your time during specific tasks.

Such functions are used for calculating the values & manipulation of data. It also has two -subtypes. To know more, get the best Programming Assignment Help to learn more about it.

  1. Scalar FunctionSuch type of function always operates on a single value & also returns it.

Methods of Creating Scalar Function

For creating the scalar function, you need to use the statement given below:

Scalar Function Image

Let’s define its Syntax: 

  • First, you have to describe the name of the function. The name of the Schema is non-compulsory here. It will use the do by default if you do not set it explicitly.
  • 2ndly, you have to specify the parameters after the function name.
  • In the 3rd step, you need to specify the return value in the returns statement.
  • At last, write the RETURN statement for returning the value inside the particular function.
  • Seek the best Programming Homework Help to know more about it.

Now, what if you want to change the scalar function? For this, you can always use the ALTER command instead of CREATE. The remaining statement is the same:

Scalar Function Remaining Image

Now to remove the Scalar function, use the DROP function statement, like:

  • DROP FUNCTION [ Schema_name.] function _name;

2. Aggregate Function

Such types of functions always work on the values which are collected. This function also returns the value. To know more, you need to ask for Programming Homework Help.

Aggregate Function Description
Count() This function returns the number of counts from all the collected values.
AVG() Returns the average of all the values in
Max () & Min() Returns the max & min of all the values from the collection of values.

2. User Defined Function

These are the server functions that the developer uses in the database. Such types of user-defined functions are also known as “user-defined functions”. Such functions may accept many parameters and perform specific actions which are helpful, and it also helps in returning the data.

These types of custom functions always help simplify database development by adding different kinds of complex logic & also making it available for reusing whenever any similar functionality is required.

Such functions also hold the code which is needed to query the data. It improves the accessibility, functionality & readability of any query in the SQL. The user in the database makes such types of functions. There are three types of subtypes of this function which the Programming Assignment Help will explain much better.

  • Scalar Function: As discussed above, the scalar function returns the value from the system’s database.
  • Inline-Tabled Value Function: This function always returns the table variable execute by the process. Here, the table variable value is procured from the single select statement. You can always take programming homework help to understand this function properly.
  • Multi-Statement Function: In this function, the user returns the table variable. Also the table – variable is always explicitly declared & defined; its values are derived from multiple SQL statements.

All these are major sub-sets of user-defined functions. Now we will discuss some other aspects of Structured Query Language.

SQL Command Types & Syntax

As discussed above, SQL language is used for accessing, extracting & changing relational databases. Due to its programming nature, it has various commands as well as Syntax like:

These commands are divided into various types. Some of them are given below:

  • Data Definition Language (DDL): It is also called data definition command because it is used to define the data – tables. Seek the top Programming homework Help to know more about it.
  • Data Manipulation Language (DML): They help in manipulating the data in existing tables by adding, subtracting & changing data. DDL Commands are used to define data storage; on the other hand, DML commands perform in the tables that the DDL Commands determine.
  • Data Query Language: This type of command is used to make queries in the information system. It is used to get specific data from the tables. Such kinds of orders are also assembled with the DML commands many times.
  • Data Control Language: Such commands are used to repeal user access. You can also grant user access privileges. You need to ask for programming homework help to know better about this command.
  • Transaction Control Language: Such types of commands in the SQL are used to modify the data.

SQL Syntax

They are the set of rules which explain how these commands are written & formatted. This makes it similar to other programming languages. Let’s define some components of the SQL.

  • SQL statements always start with their command but end with the semicolon. For eg:

SELECT * From CUSTOMERS;

Here extract all the information in the table.

  • These commands are case-sensitive, which means they are written in uppercase, lowercase & also their combination.
  • These commands can also add many flows of control programs, which means they can incorporate row selection & incorporate tables. Get the top programming assignment help in Canada to know more about such orders.

Now we have discussed various things about SQL. If you need assignment assistance, go for the Assignments Help Lite platform. Already thousands of students in Canada are taking their services. Due to this, many call them the best Programming Homework Help in Canada.

Frequently Asked Questions

1. What is a Unique & Foreign Key?

Unique keys identify each record in a particular database & providing uniqueness in every row & column. On the other hand, a foreign key is like a table related to a different table’s primary key.

2. Define the term Normalisation.

It is the process of minimising dependency by organising tables & fields in a particular database.

3. What is the cursor in the database?

It is an identifier that is associated with a group of rows. A pointer to the current row in a buffer can also be called a pointer.