Finally, we are going to start SQL aggregate functions in this article. As well as, we define all types of aggregate functions Max, Min, Count, Avg, and Sum. So, this is a simple topic for learning aggregate functions in SQL.
Firstly, we define the complex queries in which we need aggregate functions. Therefore, we have some relative topics to describe aggregate functions with the example.
Also, implement SQL aggregate functions string as well as, group by example. So, that how to implement in SQL syntax all theses example of aggregate functions list in DBMS.
SQL Aggregate Functions
In this paragraph, we find out all types of SQL aggregate functions with a single SQL query. So, When have to used aggregate function when any complex query will need used group by.
Rather than, we use the core query than include aggregate functions in SQL. Therefore, Where we used these functions in SQL will be defined in the SQL table.
Here, Find the following type of aggregate functions List.
MAX – To find the number of the maximum values in the SQL table.
MIN – Number of the minimum values in the table.
COUNT – Get the number of count values in the SQL table.
AVG – Find average values in the SQL table.
SUM – Return the summation of all non-null values in the SQL table.
All the above, I have to define the aggregate function list to consider its namely with return values in the SQL table. As well as, I am going to start to implement an example of a table.
SQL Aggregate Functions Example
Similarly, it’s an important whole function that is cover in this example. Also, you can see how aggregate functions work in SQL in this example.
Firstly, you have a table in SQL Server which we apply this function for return tables values. So, when you have a table in the database then apply in the SQL query code likewise as you want.
So, We have to show a table, for example, a table name is the employee table to find and check it. Also, learn a similar topic it is the most important point for the basic concept Relational Algebra
( Employee )
Over there, some rows in the employee table and has three column id, name, and salary. In short, one by one we give you aggregate function types example.
SQL Aggregate Functions List
Usually, as we discuss aggregate function in SQL list inn the above section but here, show the step by step with the example. As well as, we show the table for each aggregate type. Here, all aggregate functions list follow these steps.
So, let’s start with ‘Max‘ values query from the employee table.
SELECT max( salary ) FROM Employee;
As a result, return maximum value in the employee table 4,000. so, as you know that on the above table gave a salary column which has a maximum value of show that is the solution.
Now, ‘Min‘ value query of the employee table.
SELECT min( salary ) FROM Employee;
As a result, the return minimum value of a salary in employee table 1,000. So, in the above section, we define a table in which the table has minimum table values 1000.
Therefore, we get a result for harry salary because the whole salary column gets one value. So, if there have the same multiple values in this salary column than the result shows two times.
Also, there have multiple two or more values available there then the return comes to a number of times minimum same values in the salary column. As well as, there has a null value but null values can be called empty it is not acceptable value.
SQL Aggregate Functions First
Here, ‘COUNT‘ value query from the employee table.
SELECT count( * ) FROM Employee;
As a result, in the employee table number of rows, 5 then results must get 5 counts. So, as you know ‘*’ symbol show for all select values. More find the best topic SQL Insert Multiple Row
Therefore, when got this result whole table number of rows. Also, if we want result only salary column than apply these queries.
SELECT count ( salary ) FROM Employee;
Therefore, the only salary column got count 4. So, why we got 4 because there has a null value in the salary column which is empty it is not value denoted only show null.
Next, ‘AVG’ value query from the employee table.
SELECT avg( Salary ) FROM Employee;
As a result, the whole salary column got an average result of how SQL used formula for average values. Otherwise, this is the formula of return average value.
Avg( salary ) = SUM( salary ) / count ( salary )
Similarly, ‘SUM’ value query from the employee table.
SELECT sum( salary ) FROM Employee;
As a result, the return of the value of the sum 10,000. In this case, all numbers of total values in the column summation.
likewise, above the employee table in the salary column 5 rows 1,000+2,000+3,000+4,000 = 10,000. Therefore, we got the result 10,000 of the sum. In this case, you can see the last row of the salary column its value has NULL.
After that, the sum functions not calculate the last rows because there has an empty value they do not add.
Aggregate Functions String
Here, we can get the string values from the using STRING_AGG() and ignore the null value it does not the added value separator.
STRING_AGG ( expression, separator ) [ <order_clause> ]
SELECT STRING_AGG( name ) FROM Employee;
Similarly, as we know it string function when we use want string value only. Likewise, I have many emails there are add many other separators and special characters in the string then ignore all types of characters exist string.
Thus, they have many the function of another type of string will describe another article. As well as, we can be implemented conditions like group by, and another select set with the string gives an example below.
SELECT salary, STRING_AGG( name ) FROM Employee Group by salary;
Group by in SQL
In this paragraph, we have to describe and the use of the group by class. So, we are using some aggregate functions. Thus, you want to get a salary by name in the employee table.
SELECT name, sum( salary ) From Table_name Group by name;
Above the selection from the employee table in the SQL server database, we describe these points and return the value from that table.
SELECT COUNT( * ), salary FROM Table_name GROUP BY salary;
So, when seeing the result show count of salary and also showing the salary from the employee table. Also, Is HTML a Programming Language
Order by in SQL
Similarly, as we define above the sections some queries for aggregate functions same as these functions. So, there has miner change only we add order by in the query when the value retrieved from the table.
Aa an example, we have seen many results our all sections. Also, declare an employee table to give an example like that order by added in this query.
Here, Order by query
SELECT COUNT( name ), salary FROM Employee GROUP BY salary ORDER BY COUNT( name ) ASC;
Thus, you saw above is the section order by query of the SQL server database. Also, there are we used to count for select and also, using group by in which added salary column.
As well as, order by which is conditions from the name prints on ascending order. So, as the same all query you can implement as wants your to result for your projects.
Aggregate Functions in DBMS
Firstly, we to tell about the function of aggregate in DBMS which is the main specified concept in the SQL server. So, initially, this concept defines in DBMS.
Therefore, there are many data management system concepts is available. As an example, all students have confused when they learn about this subject.
So, we confirm that DBMS is basic for the data management system actually there have many all SQL servers convert that how to manage data from the database.
Here, many specified topics on how to manage your data and applying on the projects. Also, as we know that DBMS provides steps for retrieve queries which we have to learn above sections similarly has the same as more topics.
Finally, as you saw the above sections we cover all topics with the example and as well as provide SQL server queries. Thus, we defined the list of the aggregate functions in this article.
After that. if you have any queries relative to this topic drop your queries in the comment section. Also, you can learn the most important similar topic Primary Key SQL