improved sql parser.

src/main/java/com/alibaba/druid/sql/ast/expr/SQLAggregateExpr.java

@@ -19,6 +19,7 @@ import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 
+import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLExprImpl;
 import com.alibaba.druid.sql.ast.SQLKeep;
@@ -115,6 +116,10 @@ public class SQLAggregateExpr extends SQLExprImpl implements Serializable {
         this.ignoreNulls = ignoreNulls;
     }
 
+    public String toString() {
+        return SQLUtils.toSQLString(this);
+    }
+
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

src/main/java/com/alibaba/druid/sql/ast/expr/SQLFlashbackExpr.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 1999-2017 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.alibaba.druid.sql.ast.expr;
 
 import com.alibaba.druid.sql.ast.SQLExpr;

src/main/java/com/alibaba/druid/sql/ast/statement/SQLTableSource.java

@@ -17,6 +17,7 @@ package com.alibaba.druid.sql.ast.statement;
 
 import java.util.List;
 
+import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLHint;
 import com.alibaba.druid.sql.ast.SQLObject;
 
@@ -31,4 +32,7 @@ public interface SQLTableSource extends SQLObject {
     SQLTableSource clone();
 
     String computeAlias();
+
+    SQLExpr getFlashback();
+    void setFlashback(SQLExpr flashback);
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlCreateTableParser.java

@@ -72,10 +72,13 @@ public class MySqlCreateTableParser extends SQLCreateTableParser {
     }
 
     public MySqlCreateTableStatement parseCrateTable(boolean acceptCreate) {
+        MySqlCreateTableStatement stmt = new MySqlCreateTableStatement();
         if (acceptCreate) {
+            if (lexer.hasComment() && lexer.isKeepComments()) {
+                stmt.addBeforeComment(lexer.readAndResetComments());
+            }
             accept(Token.CREATE);
         }
-        MySqlCreateTableStatement stmt = new MySqlCreateTableStatement();
 
         if (identifierEquals("TEMPORARY")) {
             lexer.nextToken();

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlLexer.java

@@ -71,8 +71,7 @@ public class MySqlLexer extends Lexer {
     }
 
     public MySqlLexer(String input){
-        super(input);
-        super.keywods = DEFAULT_MYSQL_KEYWORDS;
+        this(input, true, true);
     }
 
     public MySqlLexer(String input, boolean skipComment, boolean keepComments){
@@ -407,7 +406,7 @@ public class MySqlLexer extends Lexer {
                 bufPos++;
             }
 
-            stringVal = subString(mark, bufPos + 1);
+            stringVal = subString(mark, bufPos);
             token = Token.LINE_COMMENT;
             commentCount++;
             if (keepComments) {

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -471,6 +471,9 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
     }
 
     public boolean visit(MySqlCreateTableStatement x) {
+        if (isPrettyFormat() && x.hasBeforeComment()) {
+            printlnComments(x.getBeforeCommentsDirect());
+        }
 
         print0(ucase ? "CREATE " : "create ");
 

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/stmt/OracleSelectTableSource.java

@@ -23,8 +23,4 @@ public interface OracleSelectTableSource extends SQLTableSource {
     OracleSelectPivotBase getPivot();
 
     void setPivot(OracleSelectPivotBase pivot);
-
-    SQLExpr getFlashback();
-
-    void setFlashback(SQLExpr flashback);
 }

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

@@ -27,11 +27,11 @@ import com.alibaba.druid.util.JdbcConstants;
 
 public class SQLCreateTableParser extends SQLDDLParser {
 
-    public SQLCreateTableParser(String sql){
+    public SQLCreateTableParser(String sql) {
         super(sql);
     }
 
-    public SQLCreateTableParser(SQLExprParser exprParser){
+    public SQLCreateTableParser(SQLExprParser exprParser) {
         super(exprParser);
     }
 
@@ -40,22 +40,26 @@ public class SQLCreateTableParser extends SQLDDLParser {
         if (lexer.isKeepComments() && lexer.hasComment()) {
             comments = lexer.readAndResetComments();
         }
-        
+
         SQLCreateTableStatement stmt = parseCrateTable(true);
         if (comments != null) {
             stmt.addBeforeComment(comments);
         }
-        
+
         return stmt;
     }
 
     public SQLCreateTableStatement parseCrateTable(boolean acceptCreate) {
+        SQLCreateTableStatement createTable = newCreateStatement();
+
         if (acceptCreate) {
+            if (lexer.hasComment() && lexer.isKeepComments()) {
+                createTable.addBeforeComment(lexer.readAndResetComments());
+            }
+
             accept(Token.CREATE);
         }
 
-        SQLCreateTableStatement createTable = newCreateStatement();
-
         if (identifierEquals("GLOBAL")) {
             lexer.nextToken();
 
@@ -82,21 +86,21 @@ public class SQLCreateTableParser extends SQLDDLParser {
         if (lexer.token() == Token.LPAREN) {
             lexer.nextToken();
 
-            for (;;) {
+            for (; ; ) {
                 Token token = lexer.token();
                 if (token == Token.IDENTIFIER
                         && lexer.stringVal().equalsIgnoreCase("SUPPLEMENTAL")
                         && JdbcConstants.ORACLE.equals(dbType)) {
                     this.parseCreateTableSupplementalLogingProps(createTable);
                 } else if (token == Token.IDENTIFIER //
-                    || token == Token.LITERAL_ALIAS) {
+                        || token == Token.LITERAL_ALIAS) {
                     SQLColumnDefinition column = this.exprParser.parseColumn();
                     createTable.getTableElementList().add(column);
                 } else if (token == Token.PRIMARY //
-                           || token == Token.UNIQUE //
-                           || token == Token.CHECK //
-                           || token == Token.CONSTRAINT
-                           || token == Token.FOREIGN) {
+                        || token == Token.UNIQUE //
+                        || token == Token.CHECK //
+                        || token == Token.CONSTRAINT
+                        || token == Token.FOREIGN) {
                     SQLConstraint constraint = this.exprParser.parseConstaint();
                     constraint.setParent(createTable);
                     createTable.getTableElementList().add((SQLTableElement) constraint);
@@ -149,5 +153,4 @@ public class SQLCreateTableParser extends SQLDDLParser {
     protected SQLCreateTableStatement newCreateStatement() {
         return new SQLCreateTableStatement(getDbType());
     }
-
-}
+}

src/main/java/com/alibaba/druid/sql/visitor/SQLASTOutputVisitor.java

@@ -3856,23 +3856,7 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
 
         printPartitionsCountAndSubPartitions(x);
 
-        List<SQLPartition> partitions = x.getPartitions();
-        int partitionsSize = partitions.size();
-        if (partitionsSize > 0) {
-            println();
-            incrementIndent();
-            print('(');
-            for (int i = 0; i < partitionsSize; ++i) {
-                println();
-                partitions.get(i).accept(this);
-                if (i != partitionsSize - 1) {
-                    print0(", ");
-                }
-            }
-            decrementIndent();
-            println();
-            print(')');
-        }
+        printSQLPartitions(x.getPartitions());
         return false;
     }
 
@@ -3894,9 +3878,29 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
 
         printPartitionsCountAndSubPartitions(x);
 
+        printSQLPartitions(x.getPartitions());
+
         return false;
     }
 
+    private void printSQLPartitions(List<SQLPartition> partitions) {
+        int partitionsSize = partitions.size();
+        if (partitionsSize > 0) {
+            print0(" (");
+            incrementIndent();
+            for (int i = 0; i < partitionsSize; ++i) {
+                println();
+                partitions.get(i).accept(this);
+                if (i != partitionsSize - 1) {
+                    print0(", ");
+                }
+            }
+            decrementIndent();
+            println();
+            print(')');
+        }
+    }
+
     protected void printPartitionsCountAndSubPartitions(SQLPartitionBy x) {
         if (x.getPartitionsCount() != null) {