Diagrams How To

Online Data Modeler offers easy to use diagraming tool with drag & drop support. Number of diagrams is limited by your user plan.

Create new diagram

Select page "Database/Diagram", choose command "Add New Diagram". Choose descriptive name, you can change it later.

Adding and editing tables to diagram

Go to "Tables" tab, check tables, which you want to have in diagram. You can remove tables from diagram by unchecking in this list, or using context menu of table.

Adding relationship (foreign key) to diagram

Online Data Modeler shows all relationships between tables, which are added to diagram. You can edit or remove existing relationship using context menu (right mouse click on relationship). When adding new relationship, drag column in master table and drop it on column in child table. You can also drop column on child table name, than ODM lets you to create new child column with the same data type as dragged master column.

Cardinality and optionality

Online Data Modeler can work with 1:1 and 1:N cardinalities. Cardinality N:N is not directly supported, you have to manually create mapping table.

• Master cardinality is allways 1
• Master relationship is mandatory, if all child relationship columns are marked as NOT NULL
• Child cardinality is by default N, you can change it in foreign key settings
• Child optionality is by default optional, you can change it in foreign key settings