1. How to cheat at Scrabble An intro to regular expressions

2. Who is Brian Rawlings? Data Architect @ Intermountain Healthcare
Database professional since 1994
B.S. degree in Computer Science
NOT an Oracle employee
NOT selling anything
twitter.com/BrianRawlings

3. Pattern Matching
Scrabble is played by forming letter tiles into patterns
Data can be like scrabble tiles
Regular expressions are used to match patterns
Learning to cheat at Scrabble can help you query data

4. Dictionary Table
CREATE TABLE TRAIN.WORD_LIST ( WORD VARCHAR2(50 BYTE) ); Table populated with a dictionary from the internet. Various sets are available.

5. Concept: REGEXP Functions
LIKE
Very simple pattern matching
REGEXP_LIKE
Does a pattern exist
REGEXP_COUNT
How many times does a pattern exist
Other Functions
REGEXP_REPLACE – Search and Replace
REGEXP_SUBSTR – Returns a substring
REGEXP_INSTR – Returns the position

6. Start Simple Use “Like” to find words starting with ‘M’ Like ‘%melt’
SELECT *
FROM train.word_list
WHERE word like 'M%';
Like ‘%melt’
Like ‘%melt%’

7. Limitations of LIKE
I've got four Ts. What words can I make with four Ts?
I've got a Q but no U. What words have a Q not followed by a U?
What words can I make with these 7 letters?

8. Start of a word Use REGEXP_LIKE to find words starting with ‘M’
SELECT *
FROM train.word_list
WHERE regexp_like(word, '^M');
^ represents the start of a word

9. Concept: Anchors Anchors allow you to specify where a match is allowed
^ Beginning of the string
$ End of a string

10. End of a word Use REGEXP_LIKE to find words ending with ‘MELT’
SELECT *
FROM train.word_list
WHERE regexp_like(word,'MELT$');
$ represents the end of a word

11. Concept: Dot What if there is only room for one character?
SELECT *
FROM train.word_list
WHERE regexp_like
(word, '^.MELT$');
‘.’ represents one character

12. Quiz How many two letter words are in the training dictionary?
How many two letter words start with Q?
How many words end with Q?
How many four letter words start with “T” end in “R”?

13. Concept: REGEX_COUNT Show words that have at least four Ts? SELECT *
FROM train.word_list
WHERE regexp_count(word, 'T') >= 4

14. Concept: Character Class[]
List words ending in a 'q' or a 'u'
SELECT *
FROM train.word_list
WHERE regexp_like(word, '[qu]$');

15. Concept: Repetition
List the words can be made with only the letters A and N
SELECT *
FROM train.word_list
WHERE regexp_like(word, '^[AN]+$')
The + means repeat this pattern 1 or more times

16. Anagrams
How many words can you make from the letters that make up your name?
SELECT word FROM train.word_list WHERE regexp_like (word,'^[BRIAN]+$')
[] brackets create a set
+ plus mean set repeat set one or more times

17. Anagrams
How many words can you make from the letters that make up your name only once?
SELECT word FROM train.word_list WHERE regexp_like(word, '^[BRIAN]+$') AND regexp_count(word, 'B') <= 1 AND regexp_count(word, 'R') <= 1 AND regexp_count(word, 'I') <= 1 AND regexp_count(word, 'A') <= 1 AND regexp_count(word, 'N') <= 1

18. Scrabble Scramble Scrabble equivalent to “Best Ball” in golf
Everyone plays at the same time
Use queries to find your best answer
60 seconds between rounds
Score your best word. Write down your score on the side of paper
Best score will choose next tiles.
Compare your best against the group best

19. Questions
I created this presentation. You are welcome to use this presentation to train your own team. But if you would like to package it and sell it for millions of dollars, let's talk. Twitter.com/BrianRawlings