Use eclipselink.jdbc.uppercase-columns
to force column names from the metadata to be uppercase.
Table 5-48 describes this persistence property's values.
When using native SQL queries, the JDBC metadata may return column names in lower case on some platforms. If the column names are uppercase in the mappings (default), they will not match. You should use this parameter to force all column names from the metadata to uppercase.
For more information, see:
"Using TopLink with the Oracle Database" in Solutions Guide for Oracle TopLink
"Introduction to Data Access" in Understanding Oracle TopLink