CS 3430 Lecture Notes - Lecture 16: Unique Key, Referential Integrity, Data Integrity

• School: App State
• Department: Computer Science
• Course: CS 3430
• Professor: Mohammad Mohebbi

Document Summary

Used in most of relational databases, i. e. databases based on rm model. It is a language; set of commands or statements. It is a comprehensive language, is both ddl and dml. Table, row, and column used for terms relation, tuple, and attribute in relational models. Set of relations with a constraint set of ic. Create database db_name : on a multiuser dbms, you need to specify which user owns this database. Create table table_name ( col1_name col1_datatype col1_properties, col2_name col2_datatype col2_properties, coln_name coln_datatype coln_properties. Integer numbers: smallint, int, and bigint; 2, 4 and 8 bytes respectively. Components are year, month, and day in the form yyyy-mm-dd. Multiple mapping functions available in rdbmss to change date formats. Timestamp automatically set itself to the current date and time. Blob (binary large object) for storing images, files, etc. You can also specify your own data type or domain, and then use it for defining table columns;