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 is any collection of data, it can be words you write on a piece of paper or a digital file. A DataBase Management System (DBMS) is a piece of software that manages databases and lets you create, edit and delete databases, their tables and their data. Examples of a DBMS are MySQL, MS SQL Server, Oracle, PostgreSQL and SQLite.