From 13c7228baf677c88c488686b1c6291d73a08dc8b Mon Sep 17 00:00:00 2001
From: wenshao <szujobs@hotmail.com>
Date: Thu, 11 May 2017 16:54:38 +0800
Subject: [PATCH] improved oracle sql parser.

---
 .../oracle/parser/OracleExprParser.java       | 16 ++++++-
 .../druid/sql/parser/SQLExprParser.java       | 46 +++++++++++++++----
 .../alibaba/druid/sql/parser/SQLParser.java   | 24 ++++++----
 3 files changed, 66 insertions(+), 20 deletions(-)

diff --git a/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleExprParser.java b/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleExprParser.java
index 5dd58fe0a0..b06efd5c3a 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleExprParser.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/oracle/parser/OracleExprParser.java
@@ -361,8 +361,13 @@ public class OracleExprParser extends SQLExprParser {
                         accept(Token.RPAREN);
                         sqlExpr = new SQLUnaryExpr(SQLUnaryOperator.Plus, sqlExpr);
                         break;
+                    case IDENTIFIER: {
+                        sqlExpr = expr();
+                        sqlExpr = new SQLUnaryExpr(SQLUnaryOperator.Plus, sqlExpr);
+                        break;
+                    }
                     default:
-                        throw new ParserException("TODO");
+                        throw new ParserException("TODO " + lexer.info());
                 }
                 return primaryRest(sqlExpr);
             case SUB:
@@ -403,6 +408,7 @@ public class OracleExprParser extends SQLExprParser {
                         lexer.nextToken();
                         break;
                     case VARIANT:
+                    case QUES:
                     case IDENTIFIER:
                         sqlExpr = expr();
                         sqlExpr = new SQLUnaryExpr(SQLUnaryOperator.Negative, sqlExpr);
@@ -985,6 +991,14 @@ public class OracleExprParser extends SQLExprParser {
 
             rightExp = equalityRest(rightExp);
 
+            expr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.NotEqual, rightExp, getDbType());
+        } else if (lexer.token() == Token.BANG) {
+            lexer.nextToken();
+            accept(Token.EQ);
+            rightExp = shift();
+
+            rightExp = equalityRest(rightExp);
+
             expr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.NotEqual, rightExp, getDbType());
         }
 
diff --git a/src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java b/src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java
index 3a417de7ef..fdf18e15bb 100644
--- a/src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java
+++ b/src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java
@@ -858,20 +858,40 @@ public class SQLExprParser extends SQLParser {
             if (lexer.token() == Token.LPAREN) {
                 lexer.nextToken();
 
-                SQLMethodInvokeExpr methodInvokeExpr = new SQLMethodInvokeExpr(name);
-                methodInvokeExpr.setOwner(expr);
-                if (lexer.token() == Token.RPAREN) {
+                if (lexer.token() == Token.DISTINCT) {
                     lexer.nextToken();
-                } else {
-                    if (lexer.token() == Token.PLUS) {
-                        methodInvokeExpr.addParameter(new SQLIdentifierExpr("+"));
+
+                    String aggreateMethodName = expr.toString() + "." + name;
+                    SQLAggregateExpr aggregateExpr = new SQLAggregateExpr(aggreateMethodName, SQLAggregateOption.DISTINCT);
+
+                    if (lexer.token() == Token.RPAREN) {
                         lexer.nextToken();
                     } else {
-                        exprList(methodInvokeExpr.getParameters(), methodInvokeExpr);
+                        if (lexer.token() == Token.PLUS) {
+                            aggregateExpr.getArguments().add(new SQLIdentifierExpr("+"));
+                            lexer.nextToken();
+                        } else {
+                            exprList(aggregateExpr.getArguments(), aggregateExpr);
+                        }
+                        accept(Token.RPAREN);
                     }
-                    accept(Token.RPAREN);
+                    expr = aggregateExpr;
+                } else {
+                    SQLMethodInvokeExpr methodInvokeExpr = new SQLMethodInvokeExpr(name);
+                    methodInvokeExpr.setOwner(expr);
+                    if (lexer.token() == Token.RPAREN) {
+                        lexer.nextToken();
+                    } else {
+                        if (lexer.token() == Token.PLUS) {
+                            methodInvokeExpr.addParameter(new SQLIdentifierExpr("+"));
+                            lexer.nextToken();
+                        } else {
+                            exprList(methodInvokeExpr.getParameters(), methodInvokeExpr);
+                        }
+                        accept(Token.RPAREN);
+                    }
+                    expr = methodInvokeExpr;
                 }
-                expr = methodInvokeExpr;
             } else {
                 expr = new SQLPropertyExpr(expr, name);
             }
@@ -1313,6 +1333,14 @@ public class SQLExprParser extends SQLParser {
 
             rightExp = equalityRest(rightExp);
 
+            expr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.NotEqual, rightExp, getDbType());
+        } else if (lexer.token() == Token.BANG) {
+            lexer.nextToken();
+            accept(Token.EQ);
+            rightExp = bitOr();
+
+            rightExp = equalityRest(rightExp);
+
             expr = new SQLBinaryOpExpr(expr, SQLBinaryOperator.NotEqual, rightExp, getDbType());
         } else if (lexer.token() == Token.COLONEQ) {
             lexer.nextToken();
diff --git a/src/main/java/com/alibaba/druid/sql/parser/SQLParser.java b/src/main/java/com/alibaba/druid/sql/parser/SQLParser.java
index c8b098a0e7..73bd72db15 100644
--- a/src/main/java/com/alibaba/druid/sql/parser/SQLParser.java
+++ b/src/main/java/com/alibaba/druid/sql/parser/SQLParser.java
@@ -112,16 +112,20 @@ public class SQLParser {
         } else if (lexer.token() == Token.LITERAL_CHARS) {
             alias = "'" + lexer.stringVal() + "'";
             lexer.nextToken();
-        } else if (lexer.token() == Token.CASE) {
-            alias = lexer.token.name();
-            lexer.nextToken();
-        } else if (lexer.token() == Token.USER) {
-            alias = lexer.stringVal();
-            lexer.nextToken();
-        } else if (lexer.token() == Token.END) {
-            alias = lexer.stringVal();
-            lexer.nextToken();
-        } 
+        } else {
+            switch (lexer.token()) {
+                case CASE:
+                case USER:
+                case LOB:
+                case END:
+                case DEFERRED:
+                    alias = lexer.stringVal();
+                    lexer.nextToken();
+                    break;
+                default:
+                    break;
+            }
+        }
 
         switch (lexer.token()) {
             case KEY: