CS 4400 Chapter Notes - Chapter 6: Pattern Matching, Boolean Data Type, Relational Model
Document Summary
Origin of sql is relational predicate calculus/tuple calculus which was initially proposed as square. From sequel to square to structured query language. More recent standards are divided into core specification and specialized extensions. Includes an authorization identifier and descriptors for each element. Each statement in sql ends with a semicolon. Named collection of schemas in an sql environment. Provide name of the table along with attributes, types and initial constraints. Relation and its tuples are actually created and stored as a file by the dmbs. Mapping functions allow you to change date formats. Plus a minimum of six positions for decimal fractions of seconds. Specifies a relative value that can be used to increment/decrement an absolute value of a date, time or timestamp. Date, time, timestamp, interval data types can be cast/converted to string formats for comparison. Makes it easier to change the data type for a domain that is used for numerous attributes.