# Calculated Columns

The '**Calculated Columns**' editor can be used to create a custom function for a particular field. 

### :clipboard: *Steps to Create a Calculated Columns*

1. **Click** on ![](https://791683593-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MVN38pxrmSRWq3e_Evi%2Fuploads%2FLmt2wHPMYncMKCcsVUsb%2Fimage.png?alt=media\&token=7b22d51c-cae3-4beb-9ecc-a01fb84021b9) columns
2. **Click** on the '**Add** **Custom Column**' icon.

<figure><img src="https://791683593-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MVN38pxrmSRWq3e_Evi%2Fuploads%2FhKF1Lay1S1CH3hF9FXG6%2Fimage.png?alt=media&#x26;token=d03362ba-b7b4-439e-a0f5-79128c6b8f2c" alt=""><figcaption></figcaption></figure>

3. &#x20;**Click** on '**Calculated Columns**'
4. **Enter** the field name in the respective space provided.
5. **Click** on the blank space below to write a **custom function**. The function needs to be written in **PostgreSQL.**

{% hint style="info" %}
**Note:** Click on **Show Documentation** to view various functions that you can use. It is recommended to use this feature with basic knowledge of **PostgreSQL.**
{% endhint %}

{% hint style="info" %}
**Hint:** Type a keyword for the field to receive suggestions to add t the editor.
{% endhint %}

{% tabs %}
{% tab title="String" %}
These are the commands available under the **'String'** format along with its Syntax.

* Character Length&#x20;

  ```
  char_length([field_name])
  ```
* All characters in Lower Case

  ```
  lower(string)
  ```
* All letters in Upper Case

  ```
  upper(string)
  ```
* String Concatenation 2

  ```
  'String: ' || integer
  ```

{% endtab %}

{% tab title="Numbers" %}
These are the commands available under the **'Number'** format along with its Syntax.

* Adding two or more field values

  ```
  [field_name1] + [field_name2]
  ```
* Subtracting two or more field values

  ```
  [field_name1] - [field_name2]
  ```
* Multiplying two or more field values

  ```
  [field_name1] * [field_name2]
  ```
* Dividing two field values

  ```
  [field_name1] / [field_name2]
  ```
* **Limit** or **Truncate** the decimal values to 'n' number of decimal places.

  ```
  trunc([field_name],n)
  ```

{% endtab %}

{% tab title="Boolean" %}

* Greaater Than **( > ) :** Returns 'true' if first condition is greter than second condition, else return 'false'&#x20;

  ```
  [field_name1] > [field_name2]
  ```
* Lesser Than **( < ) :**  Returns 'true' if the first condition is greter than the second condition, else return 'false'

  ```
  [field_name1] < [field_name2]
  ```
* Greater than or Equal to **( >= ) :** Returns 'true' if the first condition is greater than or equal to the second condition, else return 'false'

  ```
  [field_name1] >= [field_name2]
  ```
* Lesser than or Equal to **( <= ) :** Returns 'true' if the first condition is less than or equal to the second condition, else return 'false'

  ```
  [field_name1] <= [field_name2]
  ```
* Equal to **( = )** : Returns 'true' if the first condition is equal to the second condition, else return 'false'

  ```
  [field_name1] = [field_name2]
  ```
* Not Equal to **( != ) :** Returns 'true' if both conditions are not equal else, return 'false'

  ```
  [field_name1] !=[field_name2]
  ```

{% endtab %}

{% tab title="Date & Time" %}

* Display Current date

  ```
  current_date
  ```
* Extracts only Day from Order Date

  ```
  extract (day from [Order Date])
  ```
* Extracts only Month from Order Date

  ```
  extract (month from [Order Date])
  ```
* Extracts only Year from Order Date

  ```
  extract (year from [Order Date])
  ```

{% endtab %}

{% tab title="Other custom fields " %}
Trunc: Trunc removes the fractional part of the number and rounds numbers down to the nearest integer based on the value of the fractional part of the number.

```
trunc(([fieldnme])::numeric, 2)
```

Round: The round() function rounds a number to a specified number of decimal places.

```
round(([fieldnme])::numeric, 2)
```

Float: Float is used to store approximate values, not exact values. It has a precision from 1 to 53 digits.

```
float(([fieldnme])::numeric, 2)
```

Concat:  Concat() function adds two or more expressions together.

```
concat([field_1],' ',[field_2],' ',[field_3])
```

{% endtab %}
{% endtabs %}