private static void registerDefault(int sqlType, Class<?> javaType) {
        defaultTypes.put(sqlType, javaType);
        defaultSqlTypes.put(javaType, sqlType);
    }
{@code JDBCTypeMapping} defines a mapping from JDBC types to Java classes.

@author tiwe
querydsl-sql/src/main/java/com/querydsl/sql/JDBCTypeMapping.java