DiFY

Just pet project.

Stack:

• .NET 8
• Angular 17 (planning to migrate to Vue 3)

Existing functionality:

• custom entity creator on backend
• video calls

Dify Entity

Overview of creating tables

This documentation describes the configuration for creating tables in a database, using a JSON-based schema. Below is a detailed explanation of the properties required to define tables and columns, along with examples.

JSON structure example

The following JSON is an example of how to define a table and its columns:

{
  "id": "65a93638-295f-4e3a-81e2-4bb13f27edc7",
  "name": "contact",
  "caption": "Contact",
  "columns": [
    {
      "id": "835540ca-e156-4aab-9136-40e215360b9b",
      "name": "id",
      "caption": "Id",
      "type": 11,
      "isPrimaryKey": true
    },
    {
      "id": "ec787866-d762-4622-8e80-00009fabdbca",
      "name": "name",
      "caption": "Name",
      "type": 16,
      "size": 250,
      "isNullable": false
    },
    // Other columns...
  ]
}

Properties description

Table properties

• id: A unique identifier for the table (UUID format).
• name: The name of the table in the database.
• caption: A human-readable name for the table, often used in UI.
• columns: An array of column definitions that describe the structure of the table.

Column properties

• id: A unique identifier for the column (UUID format).
• name: The name of the column in the database.
• caption: A human-readable name for the column.
• type: Specifies the data type for the column (see Data Types section).
• isPrimaryKey: Indicates if the column is the primary key (optional, default: false).
• isNullable: Defines if the column allows null values (optional, default: true).
• size: Used for character & decimal types to define the maximum length (optional).
• precision: Used decimal type to define the scale (optional).
• referenceEntityId: If the column is a foreign key, this specifies the referenced entity's ID (optional).

Data types

The following table describes the available data types for columns:

Type Code	Data Type	PostgreSQL Value	Additional properties	Behavior description
8	Double	double precision (float8)	none	Type can be changed to other numeric types.
15	Single	real (float4)	none	Type can be changed to other numeric types.
10	Int16	smallint	none	Type can be changed to other numeric types.
11	Int32	integer	none	Type can be changed to other numeric types.
12	Int64	bigint	none	Type can be changed to other numeric types.
7	Decimal	decimal	size (max: 1000, default: 19), precision (default: 5, should be less than size)	Type can be changed to other numeric types, size can be modified but only to greater value, precision can be modified to any other value.
4	Currency	money	none	Type can be changed to other numeric types.
3	Boolean	boolean	none	Type cannot be changed.
16	String	text or varchar(size)	size - varchar($size)	size can be modified but only to greater value and if it was present before (if it wasn’t text)
6	DateTime	timestamp	none	Type cannot be changed.
27	DateTimeOffset	timestamptz	none	Type cannot be changed.
5	Date	date	none	Type cannot be changed.
17	Time	time	none	Type cannot be changed.
1	Binary	bytea	none	Type cannot be changed.

Best practices

• Primary key: Always define a primary key column to uniquely identify each row.
• Foreign keys: Use the referenceEntityId to establish relationships between tables.
• Nullable columns: Ensure that isNullable is set appropriately, depending on the data requirements.
• Data type changes: Follow the behavior guidelines to avoid issues when altering column types.

Dify Entity Query

to be described...