Hibernate Regexp MySQL

Question

I ask this question to show how MySQL and Hibernate work each other with Regular Expressions.

The problem:

SELECT * FROM table WHERE regexp column \'         


        

Answer 1

Basically, to use MySQL regexp function in Hibernate we need to create a "SQLFunctionTemplate".

Now, how to do it:

First: Create a class called "AppMySQLDialect" and extends from MySQLDialect then override the empty constructor and finally register the regexp function:

public class AppMySQLDialect extends MySQLDialect {
    public AppMySQLDialect() {
        super();
        /**
         * Function to evaluate regexp in MySQL
         */
        registerFunction("regexp", new SQLFunctionTemplate(Hibernate.INTEGER, "?1 REGEXP ?2"));
    }
}

Ok, now lets use it as follow:

FROM Entity E WHERE regexp(E.string2evaluate, '\d') = 1

Create your HibernateQuery and execute.