cpsdb=# SELECT * FROM FRAGMENT WHERE anchor_id = 4 and attributes->>'lang' like 'en';
Code Block
title
Json Response
collapse
true
{
"lang": "en",
"price": 699,
"title": "The Golden Compass",
"authors": [
"Philip Pullman"
],
"pub_year":1995
}
2.Using SIMILAR TO Regular Expression Keyword :
The only difference between like and similar to is to pattern matches the given string. It is similar toLIKE, except that it interprets the pattern using the SQL standard's definition of a regular expression
SIMILAR TOsupports these pattern-matching metacharacters borrowed from POSIX regular expressions:
|denotes alternation (either of two alternatives).
*denotes repetition of the previous item zero or more times.
+denotes repetition of the previous item one or more times.
?denotes repetition of the previous item zero or one time.
{m}denotes repetition of the previous item exactlymtimes.
{m,}denotes repetition of the previous itemmor more times.
{m,n}denotes repetition of the previous item at leastmand not more thanntimes.
Parentheses()can be used to group items into a single logical item.
A bracket expression[...]specifies a character class, just as in POSIX regular expressions.
#
Query
Output
1
cpsdb=# SELECT * FROM FRAGMENT WHERE anchor_id = 3 and attributes->>'pub_year'similar to '%(94|95)%';
Performance wise : As we are not making much changes for query , the performance is similar to existing query will not effect much
Implementation of Contains Operator
1.Update antlr parser to recognize this pattern 2.Implement required (native) query 3.Add Integration tests for a.filter on string leaf-value b.filter on Integer leaf-value 4.Update documentation 5.demo to team
Limitations
1. contains condition is case sensitive. 2. Only leaves can be used, leaf-list are not supported. 3. Only string and integer values are supported, boolean and float values are not supported. 4. When empty value is passed with contains it returns all the nodes that has given leaf element.