# Column

**Column Decorator**

The `Column` decorator is used to describe columns in the database within your ORM system. It takes one parameter — an object of type `ColumnDecoratorInterface`, which contains options for configuring the column.

**Parameters of `ColumnDecoratorInterface`**

* **name:**
  * Type: `string`
  * Description: Specifies the name of the column in the database. If not provided, the property name in the class is used.
* **options:**
  * Type: `ColumnOptionsDecoratorInterface`
  * Description: An object containing additional options for configuring the column.

**Parameters of `ColumnOptionsDecoratorInterface`**

* **dataType:**
  * Type: `PostgresqlDataTypes | MysqlDataTypes`
  * Description: Specifies the data type of the column depending on the database type (PostgreSQL or MySQL).
* **nullable:**
  * Type: `boolean`
  * Description: Defines whether the column can contain NULL values. Defaults to `false`.
* **length:**
  * Type: `number`
  * Description: Specifies the length of the data in the column. Applies to data types such as VARCHAR.
* **defaultValue:**
  * Type: `string | number | boolean`
  * Description: The default value for the column.
* **unique:**
  * Type: `boolean`
  * Description: Indicates whether the values in the column should be unique.

**PostgreSQL-Specific:**

* **check:**
  * Type: `string`
  * Description: Condition for a CHECK constraint. Specified only for PostgreSQL.
* **nameOfCheckConstraint:**
  * Type: `string`
  * Description: Name of the CHECK constraint. Applies only to PostgreSQL.
* **nullsNotDistinct:**
  * Type: `boolean`
  * Description: Indicates whether NULL values should be treated as distinct. Used only in PostgreSQL.
* **precision:**
  * Type: `number`
  * Description: Precision for numeric data. Applies only to PostgreSQL.
* **scale:**
  * Type: `number`
  * Description: Number of digits after the decimal point. Applies only to PostgreSQL.

**MySQL-Specific:**

* **totalNumberOfDigits:**
  * Type: `number`
  * Description: Total number of digits for numeric data. Applies only to MySQL.
* **numberOfDigitsAfterPoint:**
  * Type: `number`
  * Description: Number of digits after the decimal point for numeric data. Applies only to MySQL.
* **displayWidth:**
  * Type: `number`
  * Description: Display width for numeric data. Applies only to MySQL.
* **isUnsigned:**
  * Type: `boolean`
  * Description: Indicates whether the numeric data is unsigned. Applies only to MySQL.
* **isZerofill:**
  * Type: `boolean`
  * Description: Determines whether zeros should be added before the number to fill the width. Applies only to MySQL.
* **isAutoIncrement:**
  * Type: `boolean`
  * Description: Indicates whether the column should automatically increment its value for each new record. Applies only to MySQL.