ER-Studio is a visualization tool that helps to design various data structures and logical relationships in the database, and can be used for the design and construction of physical databases on specific platforms. It can generate sql and DM1 files
Toolbar perception
There are 5 kinds of logical relations, from left to right:
- Identifying Relationship: A relationship that must exist. The child entity must have an externally built property, and the foreign key must become the primary key of the parent entity ( not commonly used )
- Non-Identifying, Mandatory Relationship: One -to-many relationship , foreign key is not empty , mandatory constraint, child table data insertion and deletion are constrained by parent table data ( commonly used )
- Non-Identifying, Optional Relationship (): One -to-many relationship , foreign key can be empty , non-mandatory constraint, not subject to parent table data constraints
- One-to-one Relationship: One-to-one relationship ( commonly used )
- Non-Specific Relationship: Many-to-many relationship ( commonly used )
Cognition in the left column
- Create physical model after drawing ER diagram
- Generate the sql file of the database
