oracle select syntax error

in oracle, table_name Not followed by "AS"

correct:
```
SELECT * FROM table_name t
```

wrong:
```
SELECT * FROM table_name AS t
```
fixes unique method error in oracle dialect

example:
```
SELECT(ask.*) FROM(ask) WHERE(ask.id EQ askQuestId).unique
```
throw Exception

java.sql.SQLException: Invalid operation for forward only resultset : isLast
Merge pull request #89 from roymax/release/2.5

oracle select syntax error