Joe Celko's SQL Puzzles and Answers

PUZZLE 01: FISCAL YEAR TABLES <br>PUZZLE 02: ABSENTEES<br>PUZZLE 03: THE ANESTHESIA PUZZLE<br>PUZZLE 04: SECURITY BADGES <br>PUZZLE 05: ALPHA DATA <br>PUZZLE 06: HOTEL RESERVATIONS<br>PUZZLE 07: KEEPING A PORTFOLIO <br>PUZZLE 08: SCHEDULING PRINTERS <br>PUZZLE 09: AVAILABLE SEATS PUZZLE <br>PUZZLE 10: WAGES OF SIN:<br>PUZZLE 11: WORK ORDER <br>PUZZLE 12: CLAIMS STATUS <br>PUZZLE 13: TEACHERS <br>PUZZLE 14: TELEPHONE<br>PUZZLE 15: FIND THE LAST TWO SALARIES<br>PUZZLE 16: MECHANICS <br>PUZZLE 17: EMPLOYMENT AGENCY<br>PUZZLE 18: JUNK MAIL <br>PUZZLE 19: TOP SALESMEN<br>PUZZLE 20: TEST RESULTS<br>PUZZLE 21: AIRPLANES AND PILOTS<br>PUZZLE 22: LANDLORD<br>PUZZLE 23: MAGAZINE <br>PUZZLE 24 ONE IN TEN<br>PUZZLE 25: MILESTONE <br>PUZZLE 26: DATAFLOW DIAGRAMS<br>PUZZLE 27: FINDING EQUAL SETS<br>PUZZLE 28: CALCULATE THE SINE FUNCTION <br>PUZZLE 29: FIND THE MODE COMPUTATION <br>PUZZLE 30: AVERAGE SALES WAIT <br><br>PUZZLE 31: BUYING ALL THE PRODUCTS <br>PUZZLE 32: COMPUTING TAXES<br>PUZZLE 33: COMPUTING DEPRECIATION <br>PUZZLE 34: CONSULTANT BILLING <br>PUZZLE 35: REQUISITIONS<br>PUZZLE 36: DOUBLE DUTY<br>PUZZLE 37: MOVING AVERAGE <br>PUZZLE 38: JOURNAL UPDATING <br>PUZZLE 39: INSURANCE LOSSES <br>PUZZLE 40: PERMUTATIONS:<br>PUZZLE 41: BUDGETING <br>PUZZLE 42: COUNTING FISH <br>PUZZLE 43: GRADUATION <br>PUZZLE 44: PAIRS OF STYLES<br>PUZZLE 45: PEPPERONI PIZZA <br>PUZZLE 46: SALES PROMOTIONS<br>PUZZLE 47: BLOCKS OF SEATS <br>PUZZLE 48: UN-GROUPING<br>PUZZLE 49: WIDGET COUNT<br>PUZZLE 50: TWO OF THREE<br>PUZZLE 51: BUDGET VERSUS ACTUAL<br>PUZZLE 52: PERSONNEL PROBLEM<br>PUZZLE 53: COLLAPSING A TABLE BY COLUMNS<br>PUZZLE 54: POTENTIAL DUPLICATES <br>PUZZLE 55: PLAYING THE PONIES<br>PUZZLE 56: HOTEL ROOM NUMBERS<br>PUZZLE 57: GAPS - 1 <br>PUZZLE 58: GAPS - 2 <br>PUZZLE 59: MERGING TIME PERIODS <br>PUZZLE 60: BARCODES <br>PUZZLE 61: SORTING A STRING <br>PUZZLE 62: REPORT FORMATTING <br>PUZZLE 63: CONTIGUOUS GROUPINGS <br>PUZZLE 64: BOXES <br>PUZZLE 65: AGE RANGES FOR PRODUCTS<br>PUZZLE 66: FOUR CONSECUTIVE ABSENCES <br>PUZZLE 67: STABLE MARRIAGES PROBLEM<br>PUZZLE 68: CATCHING THE NEXT BUS <br>PUZZLE 69: LIFO-FIFO INVENTORY<br>PUZZLE 70: STOCK TRENDS<br>PUZZLE 71: CALCULATIONS <br>PUZZLE 72: SCHEDULING SERVICE CALLS<br>PUZZLE 73: A LITTLE DATA SCRUBBING<br>PUZZLE 74: DERIVED TABLES OR NOT?<br>PUZZLE 75: FINDING A PUB