The SQL can be directly executed on a database to create the tables and their relationships. Now that our ERD is ready, we can export it to DDL SQL. Once it is saved, you can see the relationship between the table on the canvas. Select appropriate columns as below and save it. It will open the one to many relationship dialog. To add the relation, select the employee table node and click on the “1M” button of the toolbar. We can add a one to many relationship with one employee having multiple addresses. The “employee_address” table will have employee addresses. Let's add one more table “employee_address” with columns 'id' (primary key), 'emp_id', 'addr1', 'addr2'. You can also reorder the columns using the drag handle on the column row. You can double click the table to open the dialog again and make changes. Once you save, you will see something like the screenshot below. Add the name as “table1” and then add the columns 'id' (primary key), 'name' and save it. Now we have opened the ERD tool, click on the Add button(with plus icon) on the toolbar and it will open a create table dialog. You can customise the level of depth for the relation traversing from File -> Preferences -> ERD Tool -> Options -> Table Relation Depth. pgAdmin will generate an ERD for the table including tables depending on it as well as the tables which it depends on. If you wish to start with a table, you can simply right click on the table and select the “ERD for table” option. You can right click on a database, select “ERD for database” option to generate an ERD from the database. PgAdmin allows you to create an ERD using an existing database or table as well. You will get a blank canvas to create your ERD from scratch. To open the ERD canvas, you can simply select a database and select ERD Tool from the Tools menu. The video was recorded long ago and since then the pgAdmin 4 team has introduced many improvements and features based on users feedback. The video demo here - is very useful to get a brief introduction of the ERD tool in pgAdmin 4. An ERD can give sufficient information for the database administrator to follow when developing and maintaining the database. The Entity-Relationship Diagram (ERD) tool is a database design tool that provides a graphical representation of database tables, columns, and inter-relationships.

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