> For the complete documentation index, see [llms.txt](https://docs.emobiq.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emobiq.com/emobiq-server/003-database/005-table-structure.md).

# Table Structure

## Create Table Structure

To create a new Table Structure,

1. Highlight the table which you want to add a structure to, then select the **Structure** tab. ![](/files/531UG0te5lJFUNZaGzxj)
2. Press the **Add** button located inside the table structure section. ![](/files/hhrCAmbGQxH9J6ErbK5T)
3. A new table structure will be added with several empty / default value fields inside ![](/files/YDAJN9hM8juR4fouIIti)
   * Available fields:
     * **Primary Key**
     * **Name**
     * **Type**
     * **Length**
     * **Optional**
     * **Auto Increment**

## Modifying Table Structure

To modify a Table Structure,

1. Highlight the table which structure you want to modify, then select the **Structure** tab.
2. Select the field that you want to modify
   * Available fields:
     * **Primary Key**
     * **Name**
     * **Type**
     * **Length**
     * **Optional**
     * **Auto Increment**
3. Modifying the **Primary Key** field ![](/files/V5057rG8Zq3Dd67CTyQM)
   * Check or uncheck the field to modify the **Primary Key** value
   * Notes for **Primary Key** field:
     * One primary key available for every table
     * Once a structure identified as a **Primary Key** (checked), it cannot be deleted unless it has been unchecked again
     * Once a structure identified as a **Primary Key** (checked), it's type cannot be changed unless it has been unchecked again
     * **Auto Increment** field will only be available to modify once a structure identified as a **Primary Key** (checked)
4. Modifying the **Name** field
   * Type on the field to modify the **Name** value
   * Notes for **Name** field:
     * Must be unique, cannot have multiple structure with the same name
     * Cannot be empty
     * Empty by default
5. Modifying the **Type** field
   * Select on the dropdown field to modify the **Type** value
   * Notes for **Type** field:
     * There are 8 types selection:
       * **VARCHAR**
       * **BOOLEAN**
       * **INT**
       * **DATE**
       * **TIME**
       * **DATETIME**
       * **DECIMAL**
       * **BLOB**
     * The detailed information for each supported data type can be found here: [`MariaDB-data-types`](https://mariadb.com/kb/en/data-types/)
     * **VARCHAR** will be selected by default
6. Modifying the **Length** field
   * Type on the field to modify the **Length** value
   * Notes for **Length** field:
     * Some data **Type** cannot have **Length** value
     * Each data **Type** might have a different maximum or minimum **Length** value, refer to: [`MariaDB-data-types`](https://mariadb.com/kb/en/data-types/) for the detailed information
7. Modifying the **Optional** field
   * Select on the dropdown field to modify the **Optional** value
   * Notes for **Optional** field:
     * True by default
8. Modifying the **Auto Increment** field
   * Select on the dropdown field to modify the **Auto Increment** value
   * Notes for **Auto Increment** field:
     * Only applicable if the type of the structure is an **INT**
     * Only applicable if the structure is a **Primary Key** (checked)
9. Save the project to make the structure usable in the **Content** tab

## Delete Table Structure

To delete a Table Structure,

1. Highlight the table which structure you want to delete, then select the **Structure** tab.
2. Press the **Delete** button on the right side of a structure that need to be removed. ![](/files/9WwFy9ygmpy2HjkM0vMP)
3. Take note that if a structure is a **Primary Key** (checked) it cannot be deleted, and need to be unchecked first if you want to remove it.
4. Save the project to see the structure change in the **Content** tab.