#01Beginner5 min

Your First Diagram

Create a project, add your first tables, define columns, and set up relationships. In 5 minutes you'll have a working ER diagram.

In this guide

1Sign up and create a workspace
2Create a data model
3Add your first table
4Define columns and primary keys
5Add a second table and create a relationship
6Arrange tables on the canvas

Step 1: Sign up and create a workspace

Go to app.erflow.io/register and create your free account. After signing up, you'll be prompted to create a workspace. A workspace is where all your data models live — think of it as a folder for your projects.

Give your workspace a name (e.g., "My Company" or "Personal Projects") and you're ready to go.

Step 2: Create a data model

From the workspace dashboard, click "New Data Model". Give it a name like "Blog Database" or "E-Commerce Schema". You can choose the database type (PostgreSQL, MySQL, SQLite, etc.) — this affects the column types available and the generated migrations.

After creating the data model, you'll land on the visual editor — a blank canvas ready for your tables.

Step 3: Add your first table

In the top toolbar, click the Table icon (or press the shortcut). Then click anywhere on the canvas to place your table. A dialog will appear asking for the table name — type users and confirm.

Your table appears on the canvas with a default id column (auto-increment primary key). You can drag it anywhere on the canvas.

Step 4: Define columns and primary keys

Click on the users table to select it. In the sidebar on the left, you'll see the table's columns. Click "Add Column" to add new columns:

name — type: varchar, length: 255
email — type: varchar, length: 255, unique: true
password — type: varchar, length: 255
created_at — type: timestamp, nullable: true
updated_at — type: timestamp, nullable: true

For each column, you can set properties like type, length, nullable, default value, and unique constraint. Click on a column to open its properties popover.

The id column is already marked as the primary key. If you need a composite primary key, you can select multiple columns.

Step 5: Add a second table and create a relationship

Add another table called posts with these columns:

id — auto-increment primary key (created automatically)
user_id — type: bigint, unsigned
title — type: varchar, length: 255
content — type: text
published_at — type: timestamp, nullable: true

Now create a foreign key: click the Link icon in the toolbar (or press the shortcut) to enter "relate" mode. Click on the posts table first, then click on the users table. ER Flow will create a foreign key from posts.user_id → users.id.

A relationship line appears between the two tables, showing the cardinality (one-to-many). You can click on the relationship line to configure cascade rules (ON DELETE, ON UPDATE).