# One‑to‑Many (1–Many) Module
A **One‑to‑Many (1–Many) Module** is used to display and manage **multiple related records** in the database.\
It is typically used for **detail or child data**, where one parent Entity is associated with many child records.
The 1‑Many Module presents data primarily in **tabular (Grid)** or **Card** layout, making it suitable for handling **large numbers of items and columns** efficiently.
***
### Purpose of 1–Many Module
The 1–Many Module is designed to:
* Manage collections of related records
* Display repeating data in a structured way
* Support business scenarios involving line items or lists
* Allow users to add, edit, and view multiple records under a parent entity
Typical business examples include:
* Order → Order Items
* Invoice → Invoice Lines
* Customer → Address List
***
### Layout Characteristics
A 1‑Many Module supports two primary layout styles:
* **Grid Layout**
* Table‑based presentation
* Suitable for dense data and many columns
* **Card Layout**
* Card‑based visual presentation
* Suitable for mobile‑friendly or summary views
The layout type can be configured via the module settings.
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### 1–Many Module Configuration
The 1–Many Module provides a configuration panel that can be accessed via the **Module Configuration** icon \
This configuration panel allows users to define database mapping, layout behavior, and advanced data retrieval logic.
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#### 1–Many Module Configuration Properties
| Property | Mandatory | Description |
| ---------------------- | ----------- | ----------------------------------------------------- |
| Module ID | Yes | System‑generated unique identifier |
| Module Name | Yes | Name of the module |
| Table Name | Yes | Database table associated with the module |
| Template Code | Yes | UI template (inherits from Entity) |
| Theme Code | Yes | UI theme (inherits from Entity) |
| Show List Layout | Yes | Select **GRID** or **CARD** layout |
| Module Key | Yes | Primary key field of the module |
| Prefix | No | Prefix for auto‑generated keys |
| Postfix | No | Suffix for auto‑generated keys |
| KeyLen | No | Length of key value |
| Sequence | Conditional | Database sequence for key generation |
| SQL Show List | No | Custom SQL to retrieve list data (specific to 1–Many) |
| SQL Duplicate Function | No | Used for duplicate handling logic |
| View Mode Flag | No | Set module to read‑only mode |
| Paging Flag | No | Enable pagination for large datasets |
| Ordering Flag | No | Enable column sorting in grid |
| Multiple Table Flag | No | Reserved for advanced use cases |
> **Note**\
> Properties such as `SQL Show List` are especially useful in 1–Many Modules where data retrieval logic requires joins or custom conditions.
***
### Module Actions
#### Delete Module
* This icon removes the selected 1‑Many Module from the Smart Form layout
* Deleting a module does **not** delete the underlying database table
***
### Usage Guidelines
* Use **1–Many Modules** only for repeating or child records
* Always map one 1–Many Module to **one database table**
* Enable paging and sorting when handling large datasets
* Use Grid layout for data‑dense use cases
* Use Card layout for flat or mobile‑oriented designs
* Use custom SQL only when standard configuration is insufficient
***
### Summary
The **One‑to‑Many (1–Many) Module** is essential for modeling **repeating and detail data** in Smart Forms.
Key points:
* Manages multiple records per parent entity
* Displays data in Grid or Card layouts
* Optimized for large datasets
* Strong integration with database tables
* Supports advanced SQL‑based data retrieval
Proper use of 1–Many Modules ensures Smart Forms are **scalable, structured, and aligned with real‑world master–detail business models**.
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