HHH-19215 Extends Dialect#addQueryHints to support straight_join syntax

[hogeunchung]

The goal is to expand the coverage of the query pattern as both MySQL and SingleStore support straight_join syntax, and their dialect classes rely on Dialect class to add index hints.

Example use case:

Session session = entityManager.unwrap(Session.class);
String query = "select * from table1 straight_join table2 on table1.column1 = table2.column1 where table1.column2 = 'value1' and table1.column3 = 'value2'";

List result = session
       .createNativeQuery(query, Table1.class)
       .addQueryHint("index_column3")
       .getResultList();

While there may be cases where this is useful, it could be considered a relatively unique situation.
If this change conflicts with the original intent, I understand if it is not accepted.

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https://hibernate.atlassian.net/browse/HHH-19215

[beikov]

It looks like the pattern might benefit from being more explicit about necessary whitespace:

Suggested change

	"^\\s*(select\\b.+?\\bfrom\\b.+?)(\\b(?:(?:natural )?(?:left |right |full )?(?:inner |outer |cross )?join |straight_join).+?\\b)?(\\bwhere\\b.+?)$");
	"^\\s*(select\\s.+?\\sfrom\\s.+?)(\\s(?:(?:natural\\s+)?(?:left\\s+|right\\s+|full\\s+)?(?:inner\\s|outer\\s|cross\\s)?join\\s|straight_join\\s).+?\\b)?(\\swhere\\s.+?)$");

[hogeunchung]

Thank you for the suggestion.
You're right; the original regex can't handle some queries with new lines.

Based on your suggestion, I've modified the regex as follows:

1. \\b -> \\s for improved robustness
2. (?:A\\s|B\\s|C\\s)? -> (?:A|B|C)?\\s* for better readability