1. Advanced Queries in MS Access
Hele-Mai Haav:
CSC230-Spring*03
Advanced Queries in MS Access

2. Criteria This is a constraint based on Boolean Algebra Truth Table
A B A and B A or B
T T T T
T F F T
F T F T
F F F F

3. Boolean Algebra
The Database System uses Boolean algebra to evaluate conditions that consist of multiple clauses.
The clauses are connected by these operators: AND, OR, NOT

4. Examples
a= 3, b=-1,c=2
(a > 4) and (b < 0) (a > 4) or (b < 0)
F T F T
F T
Not (b < 0) T F

5. QBE (Category= “Dog”) AND
(Color Like “*Yellow*”) AND (DateBorn>#6/1/98#)

6. Complex Queries
All dogs that are yellow or white and born after June 1 ?
(dogs AND yellow) OR (white AND born after June 1)
(dogs) AND (yellow OR white) AND (born after June 1)

7. Totals and subtotals Aggregation functions (Sum, Avg; Min..)
They operate across several rows of data and return one value

8. Totals and subtotals
Combining row-by-row calculations with aggregation
Use Where to limit the rows used for the total (e.g. Sum). Only the final total will be displayed in the result
Subtotals for each category can be created using Group By

9. Cross Tabulation
Crosstab (in MS Access) is Group By operation that works with two groups