improved sql parser.

src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleExprParser.java

@@ -400,6 +400,7 @@ public class OracleExprParser extends SQLExprParser {
                     case VARIANT:
                     case QUES:
                     case IDENTIFIER:
+                    case LITERAL_ALIAS:
                         sqlExpr = expr();
                         sqlExpr = new SQLUnaryExpr(SQLUnaryOperator.Negative, sqlExpr);
                         break;

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -3019,6 +3019,7 @@ public class SQLExprParser extends SQLParser {
         switch (lexer.token) {
             case FULL:
             case MODEL:
+            case TABLESPACE:
                 alias = lexer.stringVal();
                 lexer.nextToken();
                 break;