How to Use the MySQL Assignment Operator (:=) in Hibernate Native Queries?

Using MySQL Assignment Operator in Hibernate Native Queries

In Hibernate, executing native SQL queries often requires using specific SQL operators and syntax that may not be natively supported by the ORM framework. One such operator is the MySQL assignment operator (:=) used in the context of subqueries.

When attempting to utilize the :=" operator in a Hibernate native query, users may encounter an error similar to "Space is not allowed after parameter prefix ':'." This is because Hibernate parses the query and interprets the ":=" as a parameter placeholder, leading to confusion.

Resolving the Issue

In Hibernate 4.1.3 and later versions, this issue has been addressed. To successfully use the "=:" operator in a native query, simply escape it with a backslash (). This tells Hibernate to treat the operator as a literal instead of a parameter.

Updated Query

Here is the updated query using the backslash escape:

SELECT k.`news_master_id` AS id, @row \:= @row + 1 AS rownum
FROM keyword_news_list k
JOIN (SELECT @row \:= 0) r
WHERE k.`keyword_news_id` = :kid
ORDER BY k.`news_master_id` ASC

By escaping the "=:" operator, you instruct Hibernate to interpret it as a MySQL assignment operator rather than a parameter placeholder, enabling you to use the operator correctly in your native query.

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