Chemical entity relationship diagram

Reading the diagram

Each box is a database table and lists its mapped columns. Columns marked FK hold a relationship to another entity. The text beside a connecting line is the Doctrine association name; 1, 0..1, and 0..* indicate required single, optional single, and zero-or-more relationships respectively. This focused diagram omits the target tables for shared references such as users, projects, and locations; their foreign-key columns remain visible.

Main relationships

• chemical_chemical is the chemical definition. A definition can optionally be grouped under a chemical_main_chemical record, and can have many CMR classifications, safety icons, and safety statements.

• chemical_container represents an individual container of a chemical. Each container belongs to one chemical and can be classified by container type, method of use, and purpose.

• Container lifecycle and traceability are recorded through chemical_container_changelog, chemical_container_scanned, chemical_container_user, and the optional one-to-one external label.

• chemical_chemical_role assigns a chemical role to a user for a chemical; the role definition itself is stored in chemical_role.

Use this view when tracing chemical or container persistence. Follow an FK into the full ERD when the relationship crosses into another domain.