Custom BIT functions in HQL

public class MySQLDialect extends MySQLInnoDBDialect {

    public MySQLDialect() {
        super();
        registerFunction("bit_or", new StandardSQLFunction("BIT_OR", Hibernate.INTEGER));
        registerFunction("bitwise_and", new VarArgsSQLFunction(Hibernate.INTEGER, "", "&", ""));
        registerFunction("bitwise_or", new VarArgsSQLFunction(Hibernate.INTEGER, "", "|", ""));
    }
}
 
 String queryString = "select bit_or(cc.protocol) as protocolBitmask "
     + "from CtlCountry cc, ApHardwareTypeProfile atp, ApProfileRadio radio "
     + "where cc.platformName=atp.ctlPlatformName "
     + "and atp.profileType=:profileType "
     + "and atp.profileType=radio.profile "
     + "and cc.countryCode=:country " 
     + "and radio.radioIndex=:radioIndex "
     + "and bitwise_and(cc.protocol, radio.radioCap) = cc.protocol";

MySQL's BIT_OR(), BIT_AND() operators are like COUNT(), AVG(), they apply bit operations on all matched rows. Bitwise operators &, | apply on expression.

A strange "java.lang.IllegalStateException: No data type for node: org.hibernate.hql.ast.tree.MethodNode" error occurred when I used upper case function name "BIT_OR" in HQL. After I changed it to use lower case "bit_or", it works.