refactor sql parser.

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

@@ -33,7 +33,7 @@ public abstract class OracleSQLObjectImpl extends SQLObjectImpl implements Oracl
 
     public abstract void accept0(OracleASTVisitor visitor);
 
-    public SQLExpr clone() {
+    public OracleSQLObject clone() {
         throw new UnsupportedOperationException();
     }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/clause/FlashbackQueryClause.java

@@ -16,6 +16,7 @@
 package com.alibaba.druid.sql.dialect.oracle.ast.clause;
 
 import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObject;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObjectImpl;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 
@@ -35,6 +36,10 @@ public abstract class FlashbackQueryClause extends OracleSQLObjectImpl {
         SCN, TIMESTAMP
     }
 
+    public FlashbackQueryClause clone() {
+        throw new UnsupportedOperationException();
+    }
+
     public static class VersionsFlashbackQueryClause extends FlashbackQueryClause {
 
         private SQLExpr begin;

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/clause/ModelClause.java

@@ -418,4 +418,8 @@ public class ModelClause extends OracleSQLObjectImpl {
         }
 
     }
+
+    public ModelClause clone() {
+        throw new UnsupportedOperationException();
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/clause/PartitionExtensionClause.java

@@ -20,6 +20,7 @@ import java.util.List;
 
 import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObjectImpl;
+import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectPivotBase;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 
 public class PartitionExtensionClause extends OracleSQLObjectImpl {
@@ -57,4 +58,20 @@ public class PartitionExtensionClause extends OracleSQLObjectImpl {
         visitor.endVisit(this);
     }
 
+    public PartitionExtensionClause clone() {
+        PartitionExtensionClause x = new PartitionExtensionClause();
+
+        x.subPartition = subPartition;
+        if (partition != null) {
+            x.setPartition(partition.clone());
+        }
+
+        for (SQLName item : target) {
+            SQLName item1 = item.clone();
+            item1.setParent(x);
+            x.target.add(item1);
+        }
+
+        return x;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/clause/SampleClause.java

@@ -63,4 +63,21 @@ public class SampleClause extends OracleSQLObjectImpl {
         visitor.endVisit(this);
     }
 
+    public SampleClause clone() {
+        SampleClause x = new SampleClause();
+
+        x.block = block;
+
+        for (SQLExpr item : percent) {
+            SQLExpr item1 = item.clone();
+            item1.setParent(x);
+            x.percent.add(item1);
+        }
+
+        if (seedValue != null) {
+            x.setSeedValue(seedValue.clone());
+        }
+
+        return x;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleAnalytic.java

@@ -45,6 +45,18 @@ public class OracleAnalytic extends SQLOver implements OracleExpr {
         return this.windowing;
     }
 
+    public OracleAnalytic clone() {
+        OracleAnalytic x = new OracleAnalytic();
+
+        cloneTo(x);
+
+        if (windowing != null) {
+            x.setWindowing(windowing.clone());
+        }
+
+        return x;
+    }
+
     public void setWindowing(OracleAnalyticWindowing windowing) {
         this.windowing = windowing;
     }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleAnalyticWindowing.java

@@ -57,7 +57,7 @@ public class OracleAnalyticWindowing extends SQLObjectImpl implements OracleExpr
         this.type = type;
     }
 
-    public SQLExpr clone() {
+    public OracleAnalyticWindowing clone() {
         OracleAnalyticWindowing x = new OracleAnalyticWindowing();
         x.type = type;
         if (expr != null) {

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleArgumentExpr.java

@@ -57,4 +57,14 @@ public class OracleArgumentExpr extends OracleSQLObjectImpl implements SQLExpr {
         visitor.endVisit(this);
     }
 
+    public OracleArgumentExpr clone() {
+        OracleArgumentExpr x = new OracleArgumentExpr();
+        x.argumentName = argumentName;
+
+        if (value != null) {
+            x.setValue(value.clone());
+        }
+
+        return x;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleDatetimeExpr.java

@@ -16,6 +16,7 @@
 package com.alibaba.druid.sql.dialect.oracle.ast.expr;
 
 import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObject;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObjectImpl;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 
@@ -58,4 +59,17 @@ public class OracleDatetimeExpr extends OracleSQLObjectImpl implements SQLExpr {
         this.timeZone = timeZone;
     }
 
+    public OracleDatetimeExpr clone() {
+        OracleDatetimeExpr x = new OracleDatetimeExpr();
+
+        if (expr != null) {
+            x.setExpr(expr.clone());
+        }
+
+        if (timeZone != null) {
+            x.setTimeZone(timeZone.clone());
+        }
+
+        return x;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleRangeExpr.java

@@ -58,4 +58,18 @@ public class OracleRangeExpr extends OracleSQLObjectImpl implements SQLExpr {
         this.upBound = upBound;
     }
 
+
+    public OracleRangeExpr clone() {
+        OracleRangeExpr x = new OracleRangeExpr();
+
+        if (lowBound != null) {
+            x.setLowBound(lowBound.clone());
+        }
+
+        if (upBound != null) {
+            x.setUpBound(upBound.clone());
+        }
+
+        return x;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleSizeExpr.java

@@ -61,4 +61,15 @@ public class OracleSizeExpr extends OracleSQLObjectImpl implements OracleExpr {
     public static enum Unit {
         K, M, G, T, P, E
     }
+
+    public OracleSizeExpr clone() {
+        OracleSizeExpr x = new OracleSizeExpr();
+
+        if (value != null) {
+            x.setValue(value.clone());
+        }
+        x.unit = unit;
+
+        return x;
+    }
 }

src/main/java/com/alibaba/druid/sql/dialect/oracle/ast/expr/OracleSysdateExpr.java

@@ -36,4 +36,10 @@ public class OracleSysdateExpr extends OracleSQLObjectImpl implements SQLExpr {
         visitor.visit(this);
         visitor.endVisit(this);
     }
+
+    public OracleSysdateExpr clone() {
+        OracleSysdateExpr x = new OracleSysdateExpr();
+        x.option = option;
+        return x;
+    }
 }

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

@@ -1,64 +0,0 @@
-/*
- * 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.dialect.oracle.ast.stmt;
-
-import com.alibaba.druid.sql.SQLUtils;
-import com.alibaba.druid.sql.ast.statement.SQLSelect;
-import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
-import com.alibaba.druid.sql.visitor.SQLASTVisitor;
-
-public class OracleSelect extends SQLSelect {
-    private OracleSelectRestriction restriction;
-
-    public OracleSelect(){
-
-    }
-
-    public OracleSelectRestriction getRestriction() {
-        return this.restriction;
-    }
-
-    public void setRestriction(OracleSelectRestriction restriction) {
-        this.restriction = restriction;
-    }
-
-    public void output(StringBuffer buf) {
-        this.query.output(buf);
-        buf.append(" ");
-
-        if (this.orderBy != null) {
-            this.orderBy.output(buf);
-        }
-    }
-
-    protected void accept0(SQLASTVisitor visitor) {
-        accept0((OracleASTVisitor) visitor);
-    }
-
-    protected void accept0(OracleASTVisitor visitor) {
-        if (visitor.visit(this)) {
-            acceptChild(visitor, this.withSubQuery);
-            acceptChild(visitor, this.query);
-            acceptChild(visitor, this.restriction);
-            acceptChild(visitor, this.orderBy);
-        }
-        visitor.endVisit(this);
-    }
-    
-    public String toString() {
-        return SQLUtils.toOracleString(this);
-    }
-}

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

@@ -19,6 +19,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObject;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObjectImpl;
 
 public abstract class OracleSelectPivotBase extends OracleSQLObjectImpl {
@@ -32,4 +33,8 @@ public abstract class OracleSelectPivotBase extends OracleSQLObjectImpl {
     public List<SQLExpr> getPivotFor() {
         return this.pivotFor;
     }
+
+    public OracleSelectPivotBase clone() {
+        throw new UnsupportedOperationException();
+    }
 }

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

@@ -28,12 +28,38 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 
 public class OracleSelectQueryBlock extends SQLSelectQueryBlock {
 
-    private final List<SQLCommentHint>         hints = new ArrayList<SQLCommentHint>(1);
+    private final List<SQLCommentHint> hints       = new ArrayList<SQLCommentHint>(1);
 
-    private ModelClause                        modelClause;
+    private ModelClause                modelClause;
 
-    private final List<SQLExpr> forUpdateOf         = new ArrayList<SQLExpr>(1);
-    private boolean             skipLocked = false;
+    private final List<SQLExpr>        forUpdateOf = new ArrayList<SQLExpr>(1);
+    private boolean                    skipLocked  = false;
+
+    public OracleSelectQueryBlock clone() {
+        OracleSelectQueryBlock x = new OracleSelectQueryBlock();
+
+        super.clone(x);
+
+        for (SQLCommentHint hint : hints) {
+            SQLCommentHint hint1 = hint.clone();
+            hint1.setParent(x);
+            x.getHints().add(hint1);
+        }
+
+        if (modelClause != null) {
+            x.setModelClause(modelClause.clone());
+        }
+
+        for (SQLExpr item : forUpdateOf) {
+            SQLExpr item1 = item.clone();
+            item1.setParent(x);
+            forUpdateOf.add(item1);
+        }
+
+        x.skipLocked = skipLocked;
+
+        return x;
+    }
 
     public OracleSelectQueryBlock(){
 

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

@@ -17,6 +17,7 @@ package com.alibaba.druid.sql.dialect.oracle.ast.stmt;
 
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
+import com.alibaba.druid.sql.ast.statement.SQLTableSource;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.FlashbackQueryClause;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.PartitionExtensionClause;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.SampleClause;
@@ -33,6 +34,31 @@ public class OracleSelectTableReference extends SQLExprTableSource implements Or
 
     protected FlashbackQueryClause     flashback;
 
+    public OracleSelectTableReference clone() {
+        OracleSelectTableReference x = new OracleSelectTableReference();
+        cloneTo(x);
+
+        x.only = only;
+
+        if (pivot != null) {
+            x.setPivot(pivot.clone());
+        }
+
+        if (partition != null) {
+            x.setPartition(partition.clone());
+        }
+
+        if (sampleClause != null) {
+            x.setSampleClause(sampleClause.clone());
+        }
+
+        if (flashback != null) {
+            setFlashback(flashback.clone());
+        }
+
+        return x;
+    }
+
     public OracleSelectTableReference(){
 
     }
@@ -140,4 +166,5 @@ public class OracleSelectTableReference extends SQLExprTableSource implements Or
     public String toString () {
         return SQLUtils.toOracleString(this);
     }
+
 }

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

@@ -30,11 +30,11 @@ import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLNumericLiteralExpr;
 import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
+import com.alibaba.druid.sql.ast.statement.SQLSelect;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.OracleLobStorageClause;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.OracleStorageClause;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleCreateTableStatement;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleCreateTableStatement.DeferredSegmentCreation;
-import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSupplementalIdKey;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSupplementalLogGrp;
 import com.alibaba.druid.sql.parser.*;
@@ -211,7 +211,7 @@ public class OracleCreateTableParser extends SQLCreateTableParser {
         if (lexer.token() == Token.AS) {
             lexer.nextToken();
 
-            OracleSelect select = new OracleSelectParser(exprParser).select();
+            SQLSelect select = new OracleSelectParser(exprParser).select();
             stmt.setSelect(select);
         }
 

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

@@ -35,10 +35,7 @@ import com.alibaba.druid.sql.ast.expr.SQLTimestampExpr;
 import com.alibaba.druid.sql.ast.expr.SQLUnaryExpr;
 import com.alibaba.druid.sql.ast.expr.SQLUnaryOperator;
 import com.alibaba.druid.sql.ast.expr.SQLVariantRefExpr;
-import com.alibaba.druid.sql.ast.statement.SQLCharacterDataType;
-import com.alibaba.druid.sql.ast.statement.SQLCheck;
-import com.alibaba.druid.sql.ast.statement.SQLColumnDefinition;
-import com.alibaba.druid.sql.ast.statement.SQLUnique;
+import com.alibaba.druid.sql.ast.statement.*;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleDataTypeIntervalDay;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleDataTypeIntervalYear;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleDataTypeTimestamp;
@@ -66,7 +63,6 @@ import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleConstraint;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleConstraint.Initially;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleForeignKey;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OraclePrimaryKey;
-import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleUnique;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleUsingIndexClause;
 import com.alibaba.druid.sql.parser.Lexer;
@@ -426,16 +422,16 @@ public class OracleExprParser extends SQLExprParser {
                 return primaryRest(sqlExpr);
                 
            case CURSOR:
-                    lexer.nextToken();
-                    accept(Token.LPAREN);
-                    
-                    OracleSelect select = createSelectParser().select();
-                    OracleCursorExpr cursorExpr = new OracleCursorExpr(select);
-                    
-                    accept(Token.RPAREN);
-                    
-                    sqlExpr = cursorExpr;
-                    return  primaryRest(sqlExpr);
+                lexer.nextToken();
+                accept(Token.LPAREN);
+
+                SQLSelect select = createSelectParser().select();
+                OracleCursorExpr cursorExpr = new OracleCursorExpr(select);
+
+                accept(Token.RPAREN);
+
+                sqlExpr = cursorExpr;
+                return  primaryRest(sqlExpr);
            case MODEL:
            case PCTFREE:
            case INITRANS:

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

@@ -47,7 +47,6 @@ import com.alibaba.druid.sql.dialect.oracle.ast.clause.OracleWithSubqueryEntry;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.PartitionExtensionClause;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.SampleClause;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.SearchClause;
-import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectJoin;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectPivot;
 import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectQueryBlock;
@@ -71,8 +70,8 @@ public class OracleSelectParser extends SQLSelectParser {
         super(exprParser);
     }
 
-    public OracleSelect select() {
-        OracleSelect select = new OracleSelect();
+    public SQLSelect select() {
+        SQLSelect select = new SQLSelect();
 
         withSubquery(select);
 
@@ -376,7 +375,7 @@ public class OracleSelectParser extends SQLSelectParser {
 
             accept(Token.ON);
             accept(Token.LPAREN);
-            OracleSelect subQuery = this.select();
+            SQLSelect subQuery = this.select();
             accept(Token.RPAREN);
             referenceModelClause.setSubQuery(subQuery);
 

src/main/java/com/alibaba/druid/sql/dialect/oracle/visitor/OracleASTVisitor.java

@@ -157,10 +157,6 @@ public interface OracleASTVisitor extends SQLASTVisitor {
 
     void endVisit(OracleBinaryDoubleExpr x);
 
-    boolean visit(OracleSelect x);
-
-    void endVisit(OracleSelect x);
-
     boolean visit(OracleCursorExpr x);
 
     void endVisit(OracleCursorExpr x);

src/main/java/com/alibaba/druid/sql/dialect/oracle/visitor/OracleASTVisitorAdapter.java

@@ -65,13 +65,6 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitorAdapter;
 
 public class OracleASTVisitorAdapter extends SQLASTVisitorAdapter implements OracleASTVisitor {
 
-    public boolean visit(OracleSelect x) {
-        return true;
-    }
-
-    public void endVisit(OracleSelect x) {
-    }
-
     @Override
     public void endVisit(OraclePLSQLCommitStatement astNode) {
 

src/main/java/com/alibaba/druid/sql/dialect/oracle/visitor/OracleOutputVisitor.java

@@ -243,14 +243,6 @@ public class OracleOutputVisitor extends SQLASTOutputVisitor implements OracleAS
     }
 
     public boolean visit(SQLSelect x) {
-        if (x instanceof OracleSelect) {
-            return visit((OracleSelect) x);
-        }
-
-        return super.visit(x);
-    }
-
-    public boolean visit(OracleSelect x) {
         if (x.getWithSubQuery() != null) {
             x.getWithSubQuery().accept(this);
             println();
@@ -899,11 +891,6 @@ public class OracleOutputVisitor extends SQLASTOutputVisitor implements OracleAS
 
     }
 
-    @Override
-    public void endVisit(OracleSelect x) {
-
-    }
-
     @Override
     public boolean visit(OracleCursorExpr x) {
         print0(ucase ? "CURSOR(" : "cursor(");

src/main/java/com/alibaba/druid/sql/dialect/oracle/visitor/OracleSchemaStatVisitor.java

@@ -178,14 +178,6 @@ public class OracleSchemaStatVisitor extends SchemaStatVisitor implements Oracle
         return false;
     }
 
-    public void endVisit(OracleSelect x) {
-        endVisit((SQLSelect) x);
-    }
-
-    public boolean visit(OracleSelect x) {
-        return visit((SQLSelect) x);
-    }
-
     public void endVisit(SQLSelect x) {
         if (x.getQuery() != null) {
             String table = (String) x.getQuery().getAttribute(ATTR_TABLE);

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/ast/SQLServerSelect.java

@@ -1,133 +0,0 @@
-/*
- * 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.dialect.sqlserver.ast;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import com.alibaba.druid.sql.ast.SQLExpr;
-import com.alibaba.druid.sql.ast.statement.SQLSelect;
-import com.alibaba.druid.sql.dialect.sqlserver.visitor.SQLServerASTVisitor;
-import com.alibaba.druid.sql.visitor.SQLASTVisitor;
-
-public class SQLServerSelect extends SQLSelect implements SQLServerObject {
-
-    private boolean      forBrowse;
-    private List<String> forXmlOptions = new ArrayList<String>(4);
-    private SQLExpr      xmlPath;
-
-    private SQLExpr      rowCount;
-    private SQLExpr      offset;
-
-    public boolean isForBrowse() {
-        return forBrowse;
-    }
-
-    public void setForBrowse(boolean forBrowse) {
-        this.forBrowse = forBrowse;
-    }
-
-    public List<String> getForXmlOptions() {
-        return forXmlOptions;
-    }
-
-    public void setForXmlOptions(List<String> forXmlOptions) {
-        this.forXmlOptions = forXmlOptions;
-    }
-
-    public SQLExpr getRowCount() {
-        return rowCount;
-    }
-
-    public void setRowCount(SQLExpr rowCount) {
-        if (rowCount != null) {
-            rowCount.setParent(this);
-        }
-        
-        this.rowCount = rowCount;
-    }
-
-    public SQLExpr getOffset() {
-        return offset;
-    }
-
-    public void setOffset(SQLExpr offset) {
-        if (offset != null) {
-            offset.setParent(this);
-        }
-        this.offset = offset;
-    }
-    
-    public SQLExpr getXmlPath() {
-        return xmlPath;
-    }
-
-    public void setXmlPath(SQLExpr xmlPath) {
-        if (xmlPath != null) {
-            xmlPath.setParent(this);
-        }
-        this.xmlPath = xmlPath;
-    }
-
-    @Override
-    protected void accept0(SQLASTVisitor visitor) {
-        this.accept0((SQLServerASTVisitor) visitor);
-    }
-
-    @Override
-    public void accept0(SQLServerASTVisitor visitor) {
-        if (visitor.visit(this)) {
-            acceptChild(visitor, this.query);
-            acceptChild(visitor, this.orderBy);
-            acceptChild(visitor, this.hints);
-            acceptChild(visitor, this.offset);
-            acceptChild(visitor, this.rowCount);
-        }
-
-        visitor.endVisit(this);
-    }
-
-    @Override
-    public int hashCode() {
-        final int prime = 31;
-        int result = super.hashCode();
-        result = prime * result + (forBrowse ? 1231 : 1237);
-        result = prime * result + ((forXmlOptions == null) ? 0 : forXmlOptions.hashCode());
-        result = prime * result + ((offset == null) ? 0 : offset.hashCode());
-        result = prime * result + ((rowCount == null) ? 0 : rowCount.hashCode());
-        return result;
-    }
-
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) return true;
-        if (!super.equals(obj)) return false;
-        if (getClass() != obj.getClass()) return false;
-        SQLServerSelect other = (SQLServerSelect) obj;
-        if (forBrowse != other.forBrowse) return false;
-        if (forXmlOptions == null) {
-            if (other.forXmlOptions != null) return false;
-        } else if (!forXmlOptions.equals(other.forXmlOptions)) return false;
-        if (offset == null) {
-            if (other.offset != null) return false;
-        } else if (!offset.equals(other.offset)) return false;
-        if (rowCount == null) {
-            if (other.rowCount != null) return false;
-        } else if (!rowCount.equals(other.rowCount)) return false;
-        return true;
-    }
-
-}

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/parser/SQLServerSelectParser.java

@@ -22,7 +22,6 @@ import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.ast.statement.SQLSelect;
 import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
 import com.alibaba.druid.sql.ast.statement.SQLTableSource;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelect;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
 import com.alibaba.druid.sql.parser.ParserException;
@@ -41,7 +40,7 @@ public class SQLServerSelectParser extends SQLSelectParser {
     }
 
     public SQLSelect select() {
-        SQLServerSelect select = new SQLServerSelect();
+        SQLSelect select = new SQLSelect();
 
         withSubquery(select);
 

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerASTVisitor.java

@@ -16,7 +16,6 @@
 package com.alibaba.druid.sql.dialect.sqlserver.visitor;
 
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerOutput;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelect;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.expr.SQLServerObjectReferenceExpr;
@@ -68,10 +67,6 @@ public interface SQLServerASTVisitor extends SQLASTVisitor {
 
     void endVisit(SQLServerOutput x);
 
-    boolean visit(SQLServerSelect x);
-    
-    void endVisit(SQLServerSelect x);
-
     boolean visit(SQLServerRollbackStatement x);
 
     void endVisit(SQLServerRollbackStatement x);

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerASTVisitorAdapter.java

@@ -16,7 +16,6 @@
 package com.alibaba.druid.sql.dialect.sqlserver.visitor;
 
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerOutput;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelect;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.expr.SQLServerObjectReferenceExpr;
@@ -122,16 +121,6 @@ public class SQLServerASTVisitorAdapter extends SQLASTVisitorAdapter implements
 
     }
 
-    @Override
-    public boolean visit(SQLServerSelect x) {
-        return true;
-    }
-    
-    @Override
-    public void endVisit(SQLServerSelect x) {
-        
-    }
-
     @Override
     public boolean visit(SQLServerRollbackStatement x) {
         return true;

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerOutputVisitor.java

@@ -20,7 +20,6 @@ import com.alibaba.druid.sql.ast.SQLSetQuantifier;
 import com.alibaba.druid.sql.ast.SQLStatement;
 import com.alibaba.druid.sql.ast.statement.*;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerOutput;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelect;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.expr.SQLServerObjectReferenceExpr;
@@ -417,13 +416,7 @@ public class SQLServerOutputVisitor extends SQLASTOutputVisitor implements SQLSe
         }
     }
     
-    @Override
-    public void endVisit(SQLServerSelect x) {
-        
-    }
-
-    @Override
-    public boolean visit(SQLServerSelect x) {
+    public boolean visit(SQLSelect x) {
         super.visit(x);
         if (x.isForBrowse()) {
             println();

src/main/java/com/alibaba/druid/sql/dialect/sqlserver/visitor/SQLServerSchemaStatVisitor.java

@@ -20,7 +20,6 @@ import java.util.Map;
 import com.alibaba.druid.sql.ast.statement.SQLInsertStatement;
 import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerOutput;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelect;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.expr.SQLServerObjectReferenceExpr;
@@ -149,16 +148,6 @@ public class SQLServerSchemaStatVisitor extends SchemaStatVisitor implements SQL
 
     }
 
-    @Override
-    public boolean visit(SQLServerSelect x) {
-        return super.visit(x);
-    }
-
-    @Override
-    public void endVisit(SQLServerSelect x) {
-
-    }
-
     @Override
     public boolean visit(SQLServerRollbackStatement x) {
         return true;