USE-CASES-AND-EXAMPLES.md

Clarification on usage of ILIKE, CONTAINS, IS_CONTAINED_BY, DATE_OVERLAPS and some other operator-like functions

Error: Expected =, <, <=, <>, >, >=, !=, got 'ILIKE'" (or similar) is probably one of the most common DQL errors you may experience when working with this library. The cause for is that when parsing the DQL Doctrine won't recognise ILIKE as a known operator. In fact ILIKE is registered as a boolean function. Doctrine doesn't provide easy support for implementing custom operators. This may change in the future but for now it is easier to trick the DQL parser with a boolean expression.

Example intent with DQL:

SELECT e
FROM EmailEntity e
WHERE e.subject ILIKE 'Test email'

Boolean expression that will parse and is equavelnt to teh above DQL:

SELECT e
FROM EmailEntity e
WHERE ILIKE(e.subject, 'Test email') = TRUE