用例：连接mysql和oracle数据库
问题：如果我将任何一个数据源注解为主数据源，它总是使用主数据库标识符处理并基于此形成查询。
mysql数据库

@Bean
@Primary
@Qualifier("mySqlJdbcConverter")
public JdbcConverter mySqlJdbcConverter(JdbcMappingContext mappingContext, @Lazy RelationResolver relationResolver,
        @Qualifier("mysqlJdbcOperationsReference") NamedParameterJdbcOperations mysqlJdbcOperationsReference) {
    DefaultJdbcTypeFactory jdbcTypeFactory = new DefaultJdbcTypeFactory(
            mysqlJdbcOperationsReference.getJdbcOperations());
    return new BasicJdbcConverter(mappingContext, relationResolver, mySqlJdbcCustomConversions(), jdbcTypeFactory,
            IdentifierProcessing.create(new Quoting("`"), LetterCasing.UPPER_CASE));
}

@Bean
@Primary
@Qualifier("mySqlJdbcDialect")
public Dialect mySqlJdbcDialect(final JdbcConverter JdbcConverter) {
    return MySqlDialect.INSTANCE;
}

Oracle

@Bean
@Qualifier("oracleJdbcConverter")
public JdbcConverter oracleJdbcConverter(JdbcMappingContext mappingContext, @Lazy RelationResolver relationResolver,
        @Qualifier("oracleJdbcOperationsReference") NamedParameterJdbcOperations oracleJdbcOperationsReference) {
    DefaultJdbcTypeFactory jdbcTypeFactory = new DefaultJdbcTypeFactory(
            oracleJdbcOperationsReference.getJdbcOperations());
    return new BasicJdbcConverter(mappingContext, relationResolver, oracleJdbcCustomConversions(), jdbcTypeFactory,
            IdentifierProcessing.create(new Quoting("\""), LetterCasing.UPPER_CASE));
}

@Bean
@Qualifier("oracleJdbcDialect")
@RequestScope
public Dialect oracleJdbcDialect(final JdbcMappingContext JdbcConverter) {
    return OracleDialect.INSTANCE;
}

在上述情况下，查询总是带有反引号字符。即使它正在连接到oracle数据库，但标识符总是反引号
查询：

SELECT `service`.`SERVICE_ID` AS `SERVICE_ID`, `service`.`SERVICE_NAME` AS `SERVICE_NAME` FROM `service`

我能知道为什么会这样吗？