Regular expression to search for the form: word1 * (word2 -word3 -word4) * word5

Question

MySQL

Those. the question is, what would a regular expression look like that should look for consecutive sets of words, excluding a number of words within individual chunks of text?

For example, for a query of the form:

word1 * (word2 -word3 -word4) * word5

Corresponding strings will be:

word1 word99 word2 word98 word97 word5 word1
word2 word5 Inappropriate

:

word1 word99 word2 word98 WORD4 word97 word5
word1 WORD3 word2 word5

The second day I struggle with this problem ...
I would be very grateful if someone could help.

PS This is all written to search the MySQL database using the REGEXP operator. The option using Sphinx is not suitable.

Answer 1

^word1(?=.*word2)(?!.*word3|.*word4).*word5$
A regular expression where the string starts with the word word1 and ends with the word word5 . If there are words word3 or word4 between word1 and word5 , the string does not match the pattern. It is also necessary to meet the word word2 between the words word1 and word5 .

Answer 2

Regular expressions
Look at the block "Looking forward and backward" - there is about the exclusion of words, well, in general, re-read the entire page, everything is very easily painted, if anything - write in a personal.

Answer 3

PHP example:

if(preg_match("#^слово1.*(слово2|слово3|слово4).*слово5$#isU","слово1 слово99 слово2 слово98 слово97 слово5")){
  echo 1;
} else {
  echo 2;
}

if(preg_match("#^слово1.*(слово2|слово3|слово4).*слово5$#isU","слово0 слово99 слово2 слово98 слово97 слово5")){
  echo 1;
} else {
  echo 2;
}

if(preg_match("#(?<!Сергей )Иванов#isU","Игорь Иванов")){
  echo 1;
} else {
  echo 2;
}

if(preg_match("#(?<!Сергей )Иванов#isU","Сергей Иванов")){
  echo 1;
} else {
  echo 2;
}

Answer 4

lookahead, in my opinion, is not supported in mysql
, I still can’t think of how to do this with one expression, but this option may suit:
SELECT * FROM tbl_words
WHERE txt REGEXP “word1.*(word2).*word5”
AND NOT txt REGEXP “word1. *(word3|word4).*word5"

Answer 5

if(preg_match("#^слово1(?!.*слово2|.*слово3|.*слово4).*слово5$#isU","слово1 слово99 слово4 слово98 слово97 слово5")){
  echo 1;
} else {
  echo 2;
}


if(preg_match("#^слово1(?!.*слово2|.*слово3|.*слово4).*слово5$#isU","слово1 слово99 слово54 слово98 слово97 слово5")){
  echo 1;
} else {
  echo 2;
}

As already said - everything works!