Quick start guide for PostgreSQL database design in Moon Modeler.
1. New project
To create a new project, click New on the main toolbar and select the PostgreSQL project type.
2. Add tables
Basic database objects can be added to your project/diagram by clicking the appropriate icon on the main toolbar.
Then click the diagram area. A new graphical object will appear on the diagram.
Edit properties in Right Side panel:
Alternatively, you can double click the graphics or right-click the item and choose Edit.
Table properties
Basic type settings can be specified in the section Details.
Columns
In section Columns, you can add new table columns. Specify new column name, datatype, enum, domain or JSON and click Add.
- PK indicates primary key.
- NN represents Not Null column.
Detailed column specifics can be defined in a collapsible/expandable area.
- Sample data will appear in the diagram if the Sample data mode is activated.
3. JSON and composite types
One of the key, unique features of Moon Modeler is the visualization of JSON structures. PostgreSQL supports JSON data type and you can either set the basic JSON datatype for a column or prepare a new JSON object in the diagram and then pick the newly defined JSON structure as a datatype for your table column.
Compare the following:
- table customer_basic contains column contact and the datatype is defined as JSON.
- table customer_nested also contains column contact, but instead of JSON datatype, the contact JSON object is used.
When you look at the generated script, the customer_nested table contains a basic definition of the datatype, however, in the diagram, the structure is fully visualized.
How to add JSON to diagram
To create a JSON object:
- Click the JSON icon on the main toolbar and then click the diagram.
- Define fields for the JSON object, in the example above the fields are phone, email, address.
- And then assign the object to the table column datatype in the desired table, in our case customer_nested.
4. Views, enums, procedures, functions, domains, rules, policies and other objects
All other supported objects can be added to the diagram either by clicking the Other icon on the main toolbar, selecting the object type and then clicking the diagram area or, by right-clicking the diagram area and selecting the desired object type.
Enum used in the diagram:
5. Relationships
Relationships can be created between parent and child tables (for other visual references you can use Lines and connect two graphical objects).
To add a new relationship to the diagram, click the Relationship icon, then click the parent table and then the child table. If the primary key is defined in the parent table, a new column will be added to the child table and marked as a foreign key.
Example: relationship drawn from table customer to table cart. Foreign key column customer_id was added to the child table automatically.
Read more about one-to-many relationships and many-to-many relationships.
6. Code generation
To generate an SQL script, click the SQL Script icon on the main toolbar.
How to execute the script? Use another tool, for example, PG Admin:
7. Other features and visual elements
Notes, lines and other information that can be displayed in a diagram will help you keep the structure well documented. You can also display descriptions instead of columns in the visualisations.
8. Reverse engineering and visualization of existing database structures
You can establish a connection to your PostgreSQL database and load the existing structure, incl. all supported PostgreSQL objects.
To reverse engineer a database, create a new connection:
and then click Connect and reverse engineer the existing database.
Enjoy!
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