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Below we give many of the advanced search options available with the two fields description and
comment. The example I give are all aimed at the description field, but apply to either. The key
thing to note is that matches need only match part of the string--so a search using just 2 in the
description field will match a prime with a 2 anywhere in its description.
- An expression may begin with the word
NOT (uppercase) to negate a search
- Example:
NOT [2345] will match the primes without the digits 2, 3, 4 or 5 in their
descriptions
- Example:
NOT .^ will match primes without the exponentiation operator
- An expression may contain the word
OR (uppercase) to allow a boolean search
- Example:
3^ OR 5^ will match the primes like Phi(3,-163195^8192) and 343372*3^178255-1
- Example:
2^ OR 3^ OR 5^ will return mostly primes like 3*2^478785+1 (which greatly outnumber the previous
types)
- An expression may begin with the character
^ (carat) which will only match at the beginning
of the prime description. (Using ^ anywhere else in the description field will simply match the exponentiation
operator.)
- Example:
^2 will match prime descriptions that begin with the digit 2.
Example: .^2 will match prime descriptions that have an exponent that begins with the digit 2.
- An expression may end with the character
$ (dollar sign) which will only match at the end of the prime
description.
- Example:
2$ will match prime descriptions that end with the digit 2.
Example: $2 can not match any prime (how can 2 occur after the end?)
- The character
. (period) will match any single character
- Example:
(..) will match primes with two characters in a pair of parenthesis (e.g., 43013#*R(23)^11+1)
Example: .. will match everything on the list (as there are no one-character descriptions)
Example: ^......$ will match every description with exactly six-characters.
Example: ^.?3 will match description whose first or second character is 3.
(The couplet .? matches any 0 or 1 characters).
- The character
% (percent sign) will match any (0 or more) characters.
- Example:
^2%1$ will match descriptions beginning with the digit 2 and ending
with the digit 1 (with anything else in between)
Example: % will match everything on the list.
Many, GRE constructs will
work. The fact that +, *, ( and ) are quoted (to make
searching for algebraic expressions easy) eliminates many, but you can get around this by being creative and
using the fact MySQL represents many GRE expressions using [, ], {, }, >, < and :.
Example: ^[123]{3,}[[:digit:]]{3,}* will match those beginning with at least
three digits from the set {1,2,3} followed by at least three more digits (0 through 9).
Example: ^[[:alpha:]]{1,2}( will match those beginning with one or two
letters followed by a parenthesis.
Internally % is translated to the GRE '.*'.
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