Breast cancer may cause swollen axillary lymph nodes since the lymph vessels of the breast drain into the lymph nodes of the armpit. These nodes become enlarged when cancer cells spread beyond the breast tissue.
Relational database. (Redirected from Database constraints) A relational database is a digital database whose organization is based on the relational model of data, as proposed by E. F. Codd in 1970. The various software systems used to maintain relational databases are known as a relational database management system (RDBMS).
A database management system (DBMS) is a software system that enables users to define, create and maintain the database and which provides controlled access to this database. Database Concepts and Definition of Terms. Table Naming Conventions (cont.) Each cell of the table contains exactly one atomic (single) value. Since each cell should contain only one value, it is illegal to store two year levels for a single student in a single cell (year).