A database modeling tool for creating entity relationship diagrams, relational schemas, star schemas, and SQL DDL statements. ERDPlus is a web-based database modeling tool that lets you quickly and easily create Entity Relationship Diagrams (ERDs). Works with most contemporary RDBMS tools including Oracle, MySQL, Microsoft SQL Server, PostgreSQL, Teradata, IBM DB2, Microsoft Access, and others. The notation supports drawing regular and weak entities, various types of attributes (regular, unique, multi-valued, derived, composite, and optional), and all possible cardinality constraints of relationships (mandatory-many, optional-many, mandatory-one, and optional-one). The tool supports the quick creation of foreign keys and referential integrity lines by simple click-point-connect actions. This simplifies and quickens the process of creating relational schemas. The notation distinguishes fact tables from dimension tables by using a thicker frame around fact tables.