q SQL Functions : COUNT(), AVG() and SUM() - codingstreets
Search

SQL Functions : COUNT(), AVG() and SUM()

##### In This Article, You Will Know About SQL Functions.

SQL Functions – Before moving ahead, let’s know a bit about SQL MIN() and MAX() Functions.

### SQL COUNT() Function

The COUNT() function returns the number of records after matching the specified condition.

Syntax

```				```
SELECT COUNT(column_name)
FROM table_name
WHERE condition;
```
```

### SQL AVG() Function

The AVG() function returns the average value of a numerical value’s column.

Syntax

```				```
SELECT AVG(column_name)
FROM table_name
WHERE condition;
```
```

### SQL SUM() Function

The SUM() function returns the total value of a selected numerical value’s column.

Syntax

```				```
SELECT SUM(column_name)
FROM table_name
WHERE condition;
```
```

### Example Database

Below is the example of a database table named “details.”

 Id Name Class section_id 1 Alex 5 1 2 Rolex 6 2 3 Salex 7 2 4 Lelex 8 3 5 Kelex 9 5

### SQL COUNT()

Example: Use COUNT() function to return the total number of ‘Class’.

```				```
SELECT COUNT(class)
FROM details;
```
```

Example: Use COUNT() function to return the total number of ‘Class’ for a specified condition.

```				```
SELECT COUNT(class)
FROM details
WHERE section_id = 2;
```
```

### SQL AVG()

Example: Use AVG() function to return the average value of ‘Class’.

```				```
SELECT AVG(class)
FROM details;
```
```

As a result, it returns the average value of ‘Class’ column.

Example: Use AVG() function to return the average value of ‘Class’.

```				```
SELECT AVG(class)
FROM details
WHERE section_id = 2;
```
```

As a result, it returns the average value of ‘Class’ column with a specified condition.

### SQL SUM()

Example: Use SUM() function to return the SUM value of ‘Class’.

```				```
SELECT SUM(class)
FROM details;
```
```

As a result, it returns the sum of ‘Class’ column.

Example: Use SUM() function to return the SUM value of ‘Class’.

```				```
SELECT SUM(class)
FROM details
WHERE section_id = 2;
```
```

As a result, it returns the SUM value of ‘Class’ column with a specified condition.

If you find anything incorrect in the above-discussed topic and have further questions, please comment below.

Connect on:

Share on