MIS 325 Lecture Notes - Lecture 12: Aggregate Function, Result Set, Foreign Key

• School: UT-Austin
• Department: Management Information Systems
• Course: MIS 325
• Professor: Ayvaci

Document Summary

Scalar functions: operate on a single value and return and single value. Operate on a series of values (typically values in columns) Summary query: a query that contains one or more aggregate functions. Min: can result in numeric, date, or string value. Max: can result in numeric, date, or string value. Count: can result in numeric, date, or string value. Determines how the selected rows are grouped. Determines which groups are included in the final results. Like the where clauses, but in a group level. After group by clause and before order by. Having can include aggregate function; where cannot. Having can only refer to columns in the select statement; where can refer to any column in the base table. Vector aggregate: calculating the aggregate for each group rather than for the entire result set. Scalar aggregate: aggregate functions that return a single value for all the rows in a result set.