Merge pull request #862 from wenshao/master

improved sql builder

src/main/java/com/alibaba/druid/sql/PagerUtils.java

@@ -26,6 +26,7 @@ import com.alibaba.druid.sql.ast.expr.SQLAllColumnExpr;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOpExpr;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
 import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.expr.SQLNumberExpr;
 import com.alibaba.druid.sql.ast.expr.SQLPropertyExpr;
 import com.alibaba.druid.sql.ast.statement.SQLSelect;
@@ -113,30 +114,27 @@ public class PagerUtils {
             return limitMySqlQueryBlock((MySqlSelectQueryBlock) queryBlock, dbType, offset, count);
         }
 
-        if (JdbcConstants.POSTGRESQL.equals(dbType))
-        {
-        	return limitPostgreSQLQueryBlock((PGSelectQueryBlock) queryBlock, dbType, offset, count);
+        if (JdbcConstants.POSTGRESQL.equals(dbType)) {
+            return limitPostgreSQLQueryBlock((PGSelectQueryBlock) queryBlock, dbType, offset, count);
         }
         throw new UnsupportedOperationException();
     }
 
-    private static String limitPostgreSQLQueryBlock(PGSelectQueryBlock queryBlock, String dbType,
-    	int offset, int count) {
-    		if (queryBlock.getLimit() != null)
-    		{
-    		throw new IllegalArgumentException("limit already exists.");
-    		}
+    private static String limitPostgreSQLQueryBlock(PGSelectQueryBlock queryBlock, String dbType, int offset, int count) {
+        if (queryBlock.getLimit() != null) {
+            throw new IllegalArgumentException("limit already exists.");
+        }
 
-    		    PGLimit limit = new PGLimit();
-    		    if (offset > 0)
-    		    {
-    		        limit.setOffset(new SQLNumberExpr(offset));
-    		    }
-    		    limit.setRowCount(new SQLNumberExpr(count));
-    		    queryBlock.setLimit(limit);
+        PGLimit limit = new PGLimit();
+        if (offset > 0) {
+            limit.setOffset(new SQLIntegerExpr(offset));
+        }
+        limit.setRowCount(new SQLIntegerExpr(count));
+        queryBlock.setLimit(limit);
+
+        return SQLUtils.toSQLString(queryBlock, dbType);
+    }
 
-    		    return SQLUtils.toSQLString(queryBlock, dbType);
-    		}
     private static String limitDB2(SQLSelect select, String dbType, int offset, int count) {
         SQLSelectQuery query = select.getQuery();
 
@@ -202,13 +200,13 @@ public class PagerUtils {
         SQLBinaryOpExpr gt = new SQLBinaryOpExpr(new SQLIdentifierExpr("ROWNUM"), //
                                                  SQLBinaryOperator.GreaterThan, //
                                                  new SQLNumberExpr(offset), //
-                                                 JdbcConstants.SQL_SERVER
-                                                 );
+                                                 JdbcConstants.SQL_SERVER);
         SQLBinaryOpExpr lteq = new SQLBinaryOpExpr(new SQLIdentifierExpr("ROWNUM"), //
                                                    SQLBinaryOperator.LessThanOrEqual, //
                                                    new SQLNumberExpr(count + offset), //
                                                    JdbcConstants.SQL_SERVER);
-        SQLBinaryOpExpr pageCondition = new SQLBinaryOpExpr(gt, SQLBinaryOperator.BooleanAnd, lteq, JdbcConstants.SQL_SERVER);
+        SQLBinaryOpExpr pageCondition = new SQLBinaryOpExpr(gt, SQLBinaryOperator.BooleanAnd, lteq,
+                                                            JdbcConstants.SQL_SERVER);
 
         if (query instanceof SQLSelectQueryBlock) {
             SQLServerSelectQueryBlock queryBlock = (SQLServerSelectQueryBlock) query;
@@ -233,18 +231,17 @@ public class PagerUtils {
 
             return SQLUtils.toSQLString(countQueryBlock, dbType);
         }
-        
 
         SQLServerSelectQueryBlock countQueryBlock = new SQLServerSelectQueryBlock();
         countQueryBlock.getSelectList().add(new SQLSelectItem(new SQLPropertyExpr(new SQLIdentifierExpr("XX"), "*")));
 
         countQueryBlock.setFrom(new SQLSubqueryTableSource(select, "XX"));
-        
+
         if (offset <= 0) {
             countQueryBlock.setTop(new SQLServerTop(new SQLNumberExpr(count)));
             return SQLUtils.toSQLString(countQueryBlock, dbType);
         }
-        
+
         SQLAggregateExpr aggregateExpr = new SQLAggregateExpr("ROW_NUMBER");
         SQLOrderBy orderBy = select.getOrderBy();
         aggregateExpr.setOver(new SQLOver(orderBy));
@@ -268,16 +265,14 @@ public class PagerUtils {
                 SQLExpr condition = new SQLBinaryOpExpr(new SQLIdentifierExpr("ROWNUM"), //
                                                         SQLBinaryOperator.LessThanOrEqual, //
                                                         new SQLNumberExpr(count), //
-                                                        JdbcConstants.ORACLE
-                                                        );
+                                                        JdbcConstants.ORACLE);
                 if (queryBlock.getWhere() == null) {
                     queryBlock.setWhere(condition);
                 } else {
                     queryBlock.setWhere(new SQLBinaryOpExpr(queryBlock.getWhere(), //
                                                             SQLBinaryOperator.BooleanAnd, //
                                                             condition, //
-                                                            JdbcConstants.ORACLE
-                                                            ));
+                                                            JdbcConstants.ORACLE));
                 }
 
                 return SQLUtils.toSQLString(select, dbType);

src/main/java/com/alibaba/druid/sql/builder/SQLBuilder.java

@@ -1,3 +1,19 @@
+/*
+ * Copyright 1999-2011 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.builder;
 
 

src/main/java/com/alibaba/druid/sql/builder/SQLBuilderFactory.java

@@ -1,39 +1,47 @@
+/*
+ * Copyright 1999-2011 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.builder;
 
 import com.alibaba.druid.sql.builder.impl.SQLDeleteBuilderImpl;
 import com.alibaba.druid.sql.builder.impl.SQLSelectBuilderImpl;
 import com.alibaba.druid.sql.builder.impl.SQLUpdateBuilderImpl;
-import com.alibaba.druid.sql.builder.impl.dialect.MySqlSelectBuilderImpl;
-import com.alibaba.druid.sql.builder.impl.dialect.PGSelectBuilderImpl;
-import com.alibaba.druid.util.JdbcConstants;
-
 
 public class SQLBuilderFactory {
+
     public static SQLSelectBuilder createSelectSQLBuilder(String dbType) {
-        if (JdbcConstants.MYSQL.equals(dbType)) {
-            return new MySqlSelectBuilderImpl();    
-        }
-        
-        if (JdbcConstants.POSTGRESQL.equals(dbType)) {
-            return new PGSelectBuilderImpl();    
-        }
-        
-        if (JdbcConstants.SQL_SERVER.equals(dbType)) {
-            return new PGSelectBuilderImpl();    
-        }
-        
-        if (JdbcConstants.ORACLE.equals(dbType)) {
-            return new PGSelectBuilderImpl();    
-        }
-        
         return new SQLSelectBuilderImpl(dbType);
     }
     
+    public static SQLSelectBuilder createSelectSQLBuilder(String sql, String dbType) {
+        return new SQLSelectBuilderImpl(sql, dbType);
+    }
+
     public static SQLDeleteBuilder createDeleteBuilder(String dbType) {
         return new SQLDeleteBuilderImpl(dbType);
     }
     
+    public static SQLDeleteBuilder createDeleteBuilder(String sql, String dbType) {
+        return new SQLDeleteBuilderImpl(sql, dbType);
+    }
+
     public static SQLUpdateBuilder createUpdateBuilder(String dbType) {
         return new SQLUpdateBuilderImpl(dbType);
     }
+    
+    public static SQLUpdateBuilder createUpdateBuilder(String sql, String dbType) {
+        return new SQLUpdateBuilderImpl(sql, dbType);
+    }
 }

src/main/java/com/alibaba/druid/sql/builder/SQLDeleteBuilder.java

@@ -1,11 +1,26 @@
+/*
+ * Copyright 1999-2011 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.builder;
 
-
 public interface SQLDeleteBuilder {
+
     SQLDeleteBuilder from(String table);
 
     SQLDeleteBuilder from(String table, String alias);
-    
+
     SQLDeleteBuilder limit(int rowCount);
 
     SQLDeleteBuilder limit(int rowCount, int offset);

src/main/java/com/alibaba/druid/sql/builder/SQLSelectBuilder.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 1999-2011 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.builder;
 
 import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;

src/main/java/com/alibaba/druid/sql/builder/SQLUpdateBuilder.java

@@ -1,11 +1,26 @@
+/*
+ * Copyright 1999-2011 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.builder;
 
-
 public interface SQLUpdateBuilder {
+
     SQLUpdateBuilder from(String table);
 
     SQLUpdateBuilder from(String table, String alias);
-    
+
     SQLUpdateBuilder limit(int rowCount);
 
     SQLUpdateBuilder limit(int rowCount, int offset);
@@ -15,6 +30,6 @@ public interface SQLUpdateBuilder {
     SQLUpdateBuilder whereAnd(String sql);
 
     SQLUpdateBuilder whereOr(String sql);
-    
+
     SQLUpdateBuilder set(String... items);
 }

src/main/java/com/alibaba/druid/sql/builder/UpdateBuilder.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 1999-2011 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.builder;
 
 

src/main/java/com/alibaba/druid/sql/builder/impl/SQLBuilderImpl.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 1999-2011 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.builder.impl;
 
 import com.alibaba.druid.sql.builder.SQLBuilder;

src/main/java/com/alibaba/druid/sql/builder/impl/SQLDeleteBuilderImpl.java

@@ -1,12 +1,34 @@
+/*
+ * Copyright 1999-2011 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.builder.impl;
 
+import java.util.List;
+
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.SQLStatement;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
 import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.builder.SQLDeleteBuilder;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlDeleteStatement;
+import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleDeleteStatement;
+import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGDeleteStatement;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class SQLDeleteBuilderImpl implements SQLDeleteBuilder {
 
@@ -16,6 +38,22 @@ public class SQLDeleteBuilderImpl implements SQLDeleteBuilder {
     public SQLDeleteBuilderImpl(String dbType){
         this.dbType = dbType;
     }
+    
+    public SQLDeleteBuilderImpl(String sql, String dbType){
+        List<SQLStatement> stmtList = SQLUtils.parseStatements(sql, dbType);
+
+        if (stmtList.size() == 0) {
+            throw new IllegalArgumentException("not support empty-statement :" + sql);
+        }
+
+        if (stmtList.size() > 1) {
+            throw new IllegalArgumentException("not support multi-statement :" + sql);
+        }
+
+        SQLDeleteStatement stmt = (SQLDeleteStatement) stmtList.get(0);
+        this.stmt = stmt;
+        this.dbType = dbType;
+    }
 
     public SQLDeleteBuilderImpl(SQLDeleteStatement stmt, String dbType){
         this.stmt = stmt;
@@ -85,6 +123,18 @@ public class SQLDeleteBuilderImpl implements SQLDeleteBuilder {
     }
 
     public SQLDeleteStatement createSQLDeleteStatement() {
+        if (JdbcConstants.ORACLE.equals(dbType)) {
+            return new OracleDeleteStatement();    
+        }
+        
+        if (JdbcConstants.MYSQL.equals(dbType)) {
+            return new MySqlDeleteStatement();    
+        }
+        
+        if (JdbcConstants.POSTGRESQL.equals(dbType)) {
+            return new PGDeleteStatement();    
+        }
+        
         return new SQLDeleteStatement();
     }
 

src/main/java/com/alibaba/druid/sql/builder/impl/SQLSelectBuilderImpl.java

@@ -1,10 +1,29 @@
+/*
+ * Copyright 1999-2011 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.builder.impl;
 
+import java.util.List;
+
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLOrderBy;
+import com.alibaba.druid.sql.ast.SQLStatement;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
 import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
+import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.ast.statement.SQLSelect;
 import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
@@ -14,6 +33,21 @@ import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
 import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
 import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
 import com.alibaba.druid.sql.builder.SQLSelectBuilder;
+import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectGroupBy;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit;
+import com.alibaba.druid.sql.dialect.odps.ast.OdpsSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.oracle.ast.OracleOrderBy;
+import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect;
+import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.postgresql.ast.PGOrderBy;
+import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectQueryBlock.PGLimit;
+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.util.JdbcConstants;
 
 public class SQLSelectBuilderImpl implements SQLSelectBuilder {
 
@@ -23,6 +57,22 @@ public class SQLSelectBuilderImpl implements SQLSelectBuilder {
     public SQLSelectBuilderImpl(String dbType){
         this(new SQLSelectStatement(), dbType);
     }
+    
+    public SQLSelectBuilderImpl(String sql, String dbType){
+        List<SQLStatement> stmtList = SQLUtils.parseStatements(sql, dbType);
+
+        if (stmtList.size() == 0) {
+            throw new IllegalArgumentException("not support empty-statement :" + sql);
+        }
+
+        if (stmtList.size() > 1) {
+            throw new IllegalArgumentException("not support multi-statement :" + sql);
+        }
+
+        SQLSelectStatement stmt = (SQLSelectStatement) stmtList.get(0);
+        this.stmt = stmt;
+        this.dbType = dbType;
+    }
 
     public SQLSelectBuilderImpl(SQLSelectStatement stmt, String dbType){
         this.stmt = stmt;
@@ -136,46 +186,127 @@ public class SQLSelectBuilderImpl implements SQLSelectBuilder {
 
         return this;
     }
-    
+
     @Override
     public SQLSelectBuilderImpl where(String expr) {
         SQLSelectQueryBlock queryBlock = getQueryBlock();
-        
+
         SQLExpr exprObj = SQLUtils.toSQLExpr(expr, dbType);
         queryBlock.setWhere(exprObj);
-        
+
         return this;
     }
-    
+
     @Override
     public SQLSelectBuilderImpl whereAnd(String expr) {
         SQLSelectQueryBlock queryBlock = getQueryBlock();
-        
+
         SQLExpr exprObj = SQLUtils.toSQLExpr(expr, dbType);
-        SQLExpr newCondition = SQLUtils.buildCondition(SQLBinaryOperator.BooleanAnd, exprObj, false, queryBlock.getWhere());
+        SQLExpr newCondition = SQLUtils.buildCondition(SQLBinaryOperator.BooleanAnd, exprObj, false,
+                                                       queryBlock.getWhere());
         queryBlock.setWhere(newCondition);
-        
+
         return this;
     }
-    
+
     @Override
     public SQLSelectBuilderImpl whereOr(String expr) {
         SQLSelectQueryBlock queryBlock = getQueryBlock();
-        
+
         SQLExpr exprObj = SQLUtils.toSQLExpr(expr, dbType);
-        SQLExpr newCondition = SQLUtils.buildCondition(SQLBinaryOperator.BooleanOr, exprObj, false, queryBlock.getWhere());
+        SQLExpr newCondition = SQLUtils.buildCondition(SQLBinaryOperator.BooleanOr, exprObj, false,
+                                                       queryBlock.getWhere());
         queryBlock.setWhere(newCondition);
-        
+
         return this;
     }
 
     @Override
     public SQLSelectBuilderImpl limit(int rowCount) {
-        throw new UnsupportedOperationException();
+        return limit(rowCount, 0);
     }
 
     @Override
     public SQLSelectBuilderImpl limit(int rowCount, int offset) {
+        SQLSelectQueryBlock queryBlock = getQueryBlock();
+
+        if (queryBlock instanceof MySqlSelectQueryBlock) {
+            MySqlSelectQueryBlock mySqlQueryBlock = (MySqlSelectQueryBlock) queryBlock;
+
+            Limit limit = new Limit();
+            limit.setRowCount(new SQLIntegerExpr(rowCount));
+            if (offset > 0) {
+                limit.setOffset(new SQLIntegerExpr(offset));
+            }
+
+            mySqlQueryBlock.setLimit(limit);
+
+            return this;
+        }
+
+        if (queryBlock instanceof SQLServerSelectQueryBlock) {
+            SQLServerSelectQueryBlock sqlserverQueryBlock = (SQLServerSelectQueryBlock) queryBlock;
+            if (offset <= 0) {
+                SQLServerTop top = new SQLServerTop();
+                top.setExpr(new SQLIntegerExpr(rowCount));
+                sqlserverQueryBlock.setTop(top);
+            } else {
+                throw new UnsupportedOperationException("not support offset");
+            }
+
+            return this;
+        }
+
+        if (queryBlock instanceof PGSelectQueryBlock) {
+            PGSelectQueryBlock pgQueryBlock = (PGSelectQueryBlock) queryBlock;
+            PGLimit limit = new PGLimit();
+            if (offset > 0) {
+                limit.setOffset(new SQLIntegerExpr(offset));
+            }
+            limit.setRowCount(new SQLIntegerExpr(rowCount));
+            pgQueryBlock.setLimit(limit);
+
+            return this;
+        }
+
+        if (queryBlock instanceof DB2SelectQueryBlock) {
+            DB2SelectQueryBlock db2QueryBlock = (DB2SelectQueryBlock) queryBlock;
+            if (offset <= 0) {
+                SQLExpr rowCountExpr = new SQLIntegerExpr(rowCount);
+                db2QueryBlock.setFirst(rowCountExpr);
+            } else {
+                throw new UnsupportedOperationException("not support offset");
+            }
+
+            return this;
+        }
+
+        if (queryBlock instanceof OracleSelectQueryBlock) {
+            OracleSelectQueryBlock oracleQueryBlock = (OracleSelectQueryBlock) queryBlock;
+            if (offset <= 0) {
+                SQLExpr rowCountExpr = new SQLIntegerExpr(rowCount);
+                SQLExpr newCondition = SQLUtils.buildCondition(SQLBinaryOperator.BooleanAnd, rowCountExpr, false,
+                                                               oracleQueryBlock.getWhere());
+                queryBlock.setWhere(newCondition);
+            } else {
+                throw new UnsupportedOperationException("not support offset");
+            }
+
+            return this;
+        }
+        
+        if (queryBlock instanceof OdpsSelectQueryBlock) {
+            OdpsSelectQueryBlock odpsQueryBlock = (OdpsSelectQueryBlock) queryBlock;
+
+            if (offset > 0) {
+                throw new UnsupportedOperationException("not support offset");
+            }
+
+            odpsQueryBlock.setLimit(new SQLIntegerExpr(rowCount));
+
+            return this;
+        }
+
         throw new UnsupportedOperationException();
     }
 
@@ -196,18 +327,53 @@ public class SQLSelectBuilderImpl implements SQLSelectBuilder {
     }
 
     protected SQLSelect createSelect() {
+        if (JdbcConstants.SQL_SERVER.equals(dbType)) {
+            return new SQLServerSelect();
+        }
+        if (JdbcConstants.ORACLE.equals(dbType)) {
+            return new OracleSelect();
+        }
+
         return new SQLSelect();
     }
 
     protected SQLSelectQuery createSelectQueryBlock() {
+        if (JdbcConstants.MYSQL.equals(dbType)) {
+            return new MySqlSelectQueryBlock();
+        }
+
+        if (JdbcConstants.POSTGRESQL.equals(dbType)) {
+            return new PGSelectQueryBlock();
+        }
+
+        if (JdbcConstants.SQL_SERVER.equals(dbType)) {
+            return new SQLServerSelectQueryBlock();
+        }
+
+        if (JdbcConstants.ORACLE.equals(dbType)) {
+            return new OracleSelectQueryBlock();
+        }
+
         return new SQLSelectQueryBlock();
     }
 
     protected SQLOrderBy createOrderBy() {
+        if (JdbcConstants.POSTGRESQL.equals(dbType)) {
+            return new PGOrderBy();
+        }
+
+        if (JdbcConstants.ORACLE.equals(dbType)) {
+            return new OracleOrderBy();
+        }
+
         return new SQLOrderBy();
     }
 
     protected SQLSelectGroupByClause createGroupBy() {
+        if (JdbcConstants.MYSQL.equals(dbType)) {
+            return new MySqlSelectGroupBy();
+        }
+
         return new SQLSelectGroupByClause();
     }
 

src/main/java/com/alibaba/druid/sql/builder/impl/SQLUpdateBuilderImpl.java

@@ -1,13 +1,36 @@
+/*
+ * Copyright 1999-2011 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.builder.impl;
 
+import java.util.List;
+
 import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLExpr;
+import com.alibaba.druid.sql.ast.SQLStatement;
 import com.alibaba.druid.sql.ast.expr.SQLBinaryOperator;
 import com.alibaba.druid.sql.ast.expr.SQLIdentifierExpr;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.ast.statement.SQLUpdateSetItem;
 import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
 import com.alibaba.druid.sql.builder.SQLUpdateBuilder;
+import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlUpdateStatement;
+import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleUpdateStatement;
+import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGUpdateStatement;
+import com.alibaba.druid.sql.dialect.sqlserver.ast.stmt.SQLServerUpdateStatement;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class SQLUpdateBuilderImpl implements SQLUpdateBuilder {
 
@@ -17,6 +40,22 @@ public class SQLUpdateBuilderImpl implements SQLUpdateBuilder {
     public SQLUpdateBuilderImpl(String dbType){
         this.dbType = dbType;
     }
+    
+    public SQLUpdateBuilderImpl(String sql, String dbType){
+        List<SQLStatement> stmtList = SQLUtils.parseStatements(sql, dbType);
+
+        if (stmtList.size() == 0) {
+            throw new IllegalArgumentException("not support empty-statement :" + sql);
+        }
+
+        if (stmtList.size() > 1) {
+            throw new IllegalArgumentException("not support multi-statement :" + sql);
+        }
+
+        SQLUpdateStatement stmt = (SQLUpdateStatement) stmtList.get(0);
+        this.stmt = stmt;
+        this.dbType = dbType;
+    }
 
     public SQLUpdateBuilderImpl(SQLUpdateStatement stmt, String dbType){
         this.stmt = stmt;
@@ -96,6 +135,22 @@ public class SQLUpdateBuilderImpl implements SQLUpdateBuilder {
     }
 
     public SQLUpdateStatement createSQLUpdateStatement() {
+        if (JdbcConstants.MYSQL.equals(dbType)) {
+            return new MySqlUpdateStatement();    
+        }
+        
+        if (JdbcConstants.ORACLE.equals(dbType)) {
+            return new OracleUpdateStatement();    
+        }
+        
+        if (JdbcConstants.POSTGRESQL.equals(dbType)) {
+            return new PGUpdateStatement();    
+        }
+        
+        if (JdbcConstants.SQL_SERVER.equals(dbType)) {
+            return new SQLServerUpdateStatement();    
+        }
+        
         return new SQLUpdateStatement();
     }
     

src/main/java/com/alibaba/druid/sql/builder/impl/dialect/MySqlSelectBuilderImpl.java

@@ -1,23 +0,0 @@
-package com.alibaba.druid.sql.builder.impl.dialect;
-
-import com.alibaba.druid.sql.ast.statement.SQLSelectGroupByClause;
-import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
-import com.alibaba.druid.sql.builder.impl.SQLSelectBuilderImpl;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectGroupBy;
-import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
-import com.alibaba.druid.util.JdbcConstants;
-
-public class MySqlSelectBuilderImpl extends SQLSelectBuilderImpl {
-
-    public MySqlSelectBuilderImpl(){
-        super(JdbcConstants.MYSQL);
-    }
-
-    protected SQLSelectQuery createSelectQueryBlock() {
-        return new MySqlSelectQueryBlock();
-    }
-    
-    protected SQLSelectGroupByClause createGroupBy() {
-        return new MySqlSelectGroupBy();
-    }
-}

src/main/java/com/alibaba/druid/sql/builder/impl/dialect/OracleSelectBuilderImpl.java

@@ -1,26 +0,0 @@
-package com.alibaba.druid.sql.builder.impl.dialect;
-
-import com.alibaba.druid.sql.builder.impl.SQLSelectBuilderImpl;
-import com.alibaba.druid.sql.dialect.oracle.ast.OracleOrderBy;
-import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelect;
-import com.alibaba.druid.sql.dialect.oracle.ast.stmt.OracleSelectQueryBlock;
-import com.alibaba.druid.util.JdbcConstants;
-
-public class OracleSelectBuilderImpl extends SQLSelectBuilderImpl {
-
-    public OracleSelectBuilderImpl(){
-        super(JdbcConstants.ORACLE);
-    }
-
-    protected OracleSelectQueryBlock createSelectQueryBlock() {
-        return new OracleSelectQueryBlock();
-    }
-
-    protected OracleSelect createSelect() {
-        return new OracleSelect();
-    }
-    
-    protected OracleOrderBy createOrderBy() {
-        return new OracleOrderBy();
-    }
-}

src/main/java/com/alibaba/druid/sql/builder/impl/dialect/PGSelectBuilderImpl.java

@@ -1,22 +0,0 @@
-package com.alibaba.druid.sql.builder.impl.dialect;
-
-import com.alibaba.druid.sql.builder.impl.SQLSelectBuilderImpl;
-import com.alibaba.druid.sql.dialect.postgresql.ast.PGOrderBy;
-import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectQueryBlock;
-import com.alibaba.druid.sql.dialect.postgresql.ast.stmt.PGSelectStatement;
-import com.alibaba.druid.util.JdbcConstants;
-
-public class PGSelectBuilderImpl extends SQLSelectBuilderImpl {
-
-    public PGSelectBuilderImpl(){
-        super(new PGSelectStatement(), JdbcConstants.POSTGRESQL);
-    }
-
-    protected PGSelectQueryBlock createSelectQueryBlock() {
-        return new PGSelectQueryBlock();
-    }
-    
-    protected PGOrderBy createOrderBy() {
-        return new PGOrderBy();
-    }
-}

src/main/java/com/alibaba/druid/sql/builder/impl/dialect/SQLServerSelectBuilderImpl.java

@@ -1,21 +0,0 @@
-package com.alibaba.druid.sql.builder.impl.dialect;
-
-import com.alibaba.druid.sql.builder.impl.SQLSelectBuilderImpl;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelect;
-import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerSelectQueryBlock;
-import com.alibaba.druid.util.JdbcConstants;
-
-public class SQLServerSelectBuilderImpl extends SQLSelectBuilderImpl {
-
-    public SQLServerSelectBuilderImpl(){
-        super(JdbcConstants.SQL_SERVER);
-    }
-
-    protected SQLServerSelectQueryBlock createSelectQueryBlock() {
-        return new SQLServerSelectQueryBlock();
-    }
-    
-    protected SQLServerSelect createSelect() {
-        return new SQLServerSelect();
-    }
-}

src/main/java/com/alibaba/druid/sql/dialect/mysql/ast/statement/MySqlSelectQueryBlock.java

@@ -272,6 +272,10 @@ public class MySqlSelectQueryBlock extends SQLSelectQueryBlock implements MySqlO
         public Limit(){
 
         }
+        
+        public Limit(SQLExpr rowCount){
+            this.setRowCount(rowCount);
+        }
 
         private SQLExpr rowCount;
         private SQLExpr offset;