1602020040

SQL aggregate functions are inbuilt functions that are used for performing various operations in data. Aggregate Functions are used for performing operations on multiple rows of a particular column and result in a single value. An aggregate function allows you to perform the calculation on a set of values to return the single scalar value.

We often use the aggregate functions with the GROUP BY and HAVING clauses of the SELECT statement.

Aggregate Functions are:

- AVG()
- COUNT()
- MAX()
- MIN()
- SUM()
- STDDEV()
- VARIANCE()

Let’s understand all this function with examples.

The **avg()** function is used to return an average value after the calculation performed in a numeric column.

#sql #sql aggregate

1594369800

**SQL** stands for Structured Query Language. SQL is a scripting language expected to store, control, and inquiry information put away in social databases. The main manifestation of SQL showed up in 1974, when a gathering in IBM built up the principal model of a social database. The primary business social database was discharged by Relational Software later turning out to be Oracle.

Models for SQL exist. In any case, the SQL that can be utilized on every last one of the major RDBMS today is in various flavors. This is because of two reasons:

1. The SQL order standard is genuinely intricate, and it isn’t handy to actualize the whole standard.

2. Every database seller needs an approach to separate its item from others.

Right now, contrasts are noted where fitting.

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1602020040

SQL aggregate functions are inbuilt functions that are used for performing various operations in data. Aggregate Functions are used for performing operations on multiple rows of a particular column and result in a single value. An aggregate function allows you to perform the calculation on a set of values to return the single scalar value.

We often use the aggregate functions with the GROUP BY and HAVING clauses of the SELECT statement.

Aggregate Functions are:

- AVG()
- COUNT()
- MAX()
- MIN()
- SUM()
- STDDEV()
- VARIANCE()

Let’s understand all this function with examples.

The **avg()** function is used to return an average value after the calculation performed in a numeric column.

#sql #sql aggregate

1594786380

The SQL `min()`

function is used to find the **minimum/lowest** value in the given column. The syntax for using the function is given below.

1

2

3

`**SELECT**`

`**MIN**``(``**column**``)`

`**FROM**`

`**Table**`

`**WHERE**`

`condition;`

Where, `column`

and `Table`

are the column name and table name respectively for which we need to find the minimum value. The `[WHERE](https://www.journaldev.com/18411/sql-where-clause)`

condition is used to narrow down the set of values on the basis of the `condition`

.

Let us look at an example to get a better understanding.

**Example**: The table below contains the score of 3 different students in 3 different subjects(Maths, Science, and English) out of 100.

RollNameMathsScienceEnglish1John9589902Kate7890913Alex879289

Table – Marks

Now, let us try to get the minimum marks that a student scored at **Maths**.

1

2

`**SELECT**`

`**MIN**``(Maths)`

`**FROM**`

`Marks;`

**Output:**

1

**Example –** To calculate the overall minimum marks that a student scored out of 300.

1

2

`**SELECT**`

`**MIN**``(Maths + Science + English)`

`**FROM**`

`Marks;`

**Output:**

1

`259`

We get the desired output as **Roll 2** got the lowest total marks(78 + 90 + 91 = **259**).

The SQL `max()`

function on the other hand is used to find the **maximum/highest** value in the given column. The syntax for using the function is given below.

1

2

3

`**SELECT**`

`**MAX**``(``**column**``)`

`**FROM**`

`**Table**`

`**WHERE**`

`condition;`

Similar to the `min()`

function, here too `column`

and `Table`

are the column name and table name respectively for which the maximum value is to be calculated. The `[WHERE](https://www.journaldev.com/18411/sql-where-clause)`

condition is used to narrow down the set of values on the basis of the `condition`

.

**Example –** Considering the same `Marks`

table used for the `min()`

function, let us this time try to calculate the maximum marks that a student scored in **English**.

1

2

`**SELECT**`

`**MAX**``(English)`

`**FROM**`

`Marks;`

**Output:**

1

**Example –** To calculate the maximum marks that a student scored out of 300 in **all **the subjects.

1

2

`**SELECT**`

`**MAX**``(Maths + Science + English)`

`**FROM**`

`Marks;`

**Output:**

1

`274`

From the table Marks it is clear that **Roll 1** has the highest total marks(95 + 90 + 89 = **274**). Hence, the output is justified.

#sql #functions #max #min

1598258580

In database management, an aggregate function or aggregation function, according to Wikipedia, is a function where the values of multiple rows are grouped to form a single summary value.

There are different aggregate functions, such as SUM, COUNT, MAX, MIN, AVG, etc. In this tutorial, we’ll cover the most used aggregate function in detail.

Basically an aggragate function performs a calculation on a set of values, and returns a single value.

Consider the table of `author`

that we usually use in our SQL tutorials. For illustration we added `salary`

column.

Author Tabl

Let’s see how it works.

#mysql #snippets #mysql aggregate functions #function

1618814160

In database systems in general and in SQL Server in particular, functions are pieces of code that take zero or one input and return a single output or an array.

Table-Valued Functions which are typically user-defined can return an array, but in-built SQL Server functions are typically Scalar-Valued Functions. The third class of functions in SQL Server are Aggregate-Valued Functions. The MIN and MAX SQL Server functions are Aggregate-Valued Functions.

Window Functions are a relatively new class. They perform calculations like aggregate functions but do it over a set of rows related to the current row. While an aggregate function is likely to yield a single result by working on a column, a Window Function is more likely to yield a result for each row.

The SQL Server Functions classification can also ground on data type – String Functions, Numeric Functions, and Date Functions. We can deduce that String Functions operate on string values, e.g., LENGTH().

#sql server #sql functions #sql