support sql ast object toString

src/main/java/com/alibaba/druid/sql/dialect/db2/ast/DB2StatementImpl.java

@@ -18,8 +18,14 @@ package com.alibaba.druid.sql.dialect.db2.ast;
 import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.dialect.db2.visitor.DB2ASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public abstract class DB2StatementImpl extends SQLStatementImpl implements DB2Object {
+
+    public DB2StatementImpl() {
+        super(JdbcConstants.DB2);
+    }
+
     @Override
     protected void accept0(SQLASTVisitor visitor) {
         if (visitor instanceof DB2ASTVisitor) {

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

@@ -18,10 +18,15 @@ package com.alibaba.druid.sql.dialect.mysql.ast.statement;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlAlterTableStatement extends SQLAlterTableStatement {
 
     private boolean ignore = false;
+    
+    public MySqlAlterTableStatement() {
+        super (JdbcConstants.MYSQL);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -18,10 +18,15 @@ package com.alibaba.druid.sql.dialect.mysql.ast.statement;
 import com.alibaba.druid.sql.ast.statement.SQLCreateIndexStatement;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlCreateIndexStatement extends SQLCreateIndexStatement implements MySqlStatement {
 
     private String using;
+    
+    public MySqlCreateIndexStatement() {
+        super (JdbcConstants.MYSQL);
+    }
 
     public String getUsing() {
         return using;

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

@@ -31,6 +31,7 @@ import com.alibaba.druid.sql.ast.statement.SQLSelect;
 import com.alibaba.druid.sql.dialect.mysql.ast.MySqlObjectImpl;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlCreateTableStatement extends SQLCreateTableStatement implements MySqlStatement {
 
@@ -47,7 +48,7 @@ public class MySqlCreateTableStatement extends SQLCreateTableStatement implement
     private SQLExprTableSource     like;
 
     public MySqlCreateTableStatement(){
-
+        super (JdbcConstants.MYSQL);
     }
 
     public SQLExprTableSource getLike() {

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

@@ -22,6 +22,7 @@ import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.L
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlOutputVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlDeleteStatement extends SQLDeleteStatement {
 
@@ -33,6 +34,10 @@ public class MySqlDeleteStatement extends SQLDeleteStatement {
     private SQLTableSource using;
     private SQLOrderBy     orderBy;
     private Limit          limit;
+    
+    public MySqlDeleteStatement() {
+        super (JdbcConstants.MYSQL);
+    }
 
     public boolean isLowPriority() {
         return lowPriority;

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

@@ -19,6 +19,7 @@ import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.statement.SQLRollbackStatement;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlRollbackStatement extends SQLRollbackStatement implements MySqlStatement {
 
@@ -28,7 +29,7 @@ public class MySqlRollbackStatement extends SQLRollbackStatement implements MySq
     private SQLExpr force;
 
     public MySqlRollbackStatement(){
-
+        super (JdbcConstants.MYSQL);
     }
 
     public Boolean getChain() {

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

@@ -18,9 +18,14 @@ package com.alibaba.druid.sql.dialect.mysql.ast.statement;
 import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public abstract class MySqlStatementImpl extends SQLStatementImpl implements MySqlStatement {
 
+    public MySqlStatementImpl() {
+        super(JdbcConstants.MYSQL);
+    }
+
     @Override
     protected void accept0(SQLASTVisitor visitor) {
         if (visitor instanceof MySqlASTVisitor) {

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

@@ -20,6 +20,7 @@ import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
 import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlUpdateStatement extends SQLUpdateStatement implements MySqlStatement {
 
@@ -28,6 +29,10 @@ public class MySqlUpdateStatement extends SQLUpdateStatement implements MySqlSta
 
     private boolean    lowPriority = false;
     private boolean    ignore      = false;
+    
+    public MySqlUpdateStatement() {
+        super (JdbcConstants.MYSQL);
+    }
 
     public Limit getLimit() {
         return limit;

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

@@ -147,6 +147,7 @@ import com.alibaba.druid.sql.parser.ParserException;
 import com.alibaba.druid.sql.parser.SQLSelectParser;
 import com.alibaba.druid.sql.parser.SQLStatementParser;
 import com.alibaba.druid.sql.parser.Token;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class MySqlStatementParser extends SQLStatementParser {
 
@@ -191,7 +192,7 @@ public class MySqlStatementParser extends SQLStatementParser {
 
     public SQLSelectStatement parseSelect() {
         MySqlSelectParser selectParser = new MySqlSelectParser(this.exprParser);
-        return new SQLSelectStatement(selectParser.select());
+        return new SQLSelectStatement(selectParser.select(), JdbcConstants.MYSQL);
     }
 
     public SQLUpdateStatement parseUpdateStatement() {
@@ -2131,7 +2132,7 @@ public class MySqlStatementParser extends SQLStatementParser {
             }
             return stmt;
         } else {
-            SQLSetStatement stmt = new SQLSetStatement();
+            SQLSetStatement stmt = new SQLSetStatement(getDbType());
 
             parseAssignItems(stmt.getItems(), stmt);
 
@@ -2536,7 +2537,7 @@ public class MySqlStatementParser extends SQLStatementParser {
 
         accept(Token.DATABASE);
 
-        SQLCreateDatabaseStatement stmt = new SQLCreateDatabaseStatement();
+        SQLCreateDatabaseStatement stmt = new SQLCreateDatabaseStatement(JdbcConstants.MYSQL);
         stmt.setName(this.exprParser.name());
 
         if (lexer.token() == Token.DEFAULT) {

src/main/java/com/alibaba/druid/sql/dialect/odps/ast/OdpsCreateTableStatement.java

@@ -25,6 +25,7 @@ import com.alibaba.druid.sql.ast.statement.SQLCreateTableStatement;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.dialect.odps.visitor.OdpsASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OdpsCreateTableStatement extends SQLCreateTableStatement {
 
@@ -35,6 +36,10 @@ public class OdpsCreateTableStatement extends SQLCreateTableStatement {
     protected List<SQLColumnDefinition> partitionColumns = new ArrayList<SQLColumnDefinition>(2);
 
     protected SQLExpr                   lifecycle;
+    
+    public OdpsCreateTableStatement() {
+        super (JdbcConstants.ODPS);
+    }
 
     public SQLExprTableSource getLike() {
         return like;

src/main/java/com/alibaba/druid/sql/dialect/odps/ast/OdpsInsertStatement.java

@@ -23,12 +23,17 @@ import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
 import com.alibaba.druid.sql.dialect.odps.visitor.OdpsASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OdpsInsertStatement extends SQLStatementImpl implements SQLStatement {
 
     private SQLSubqueryTableSource from;
 
     private List<OdpsInsert>       items = new ArrayList<OdpsInsert>();
+    
+    public OdpsInsertStatement() {
+        super (JdbcConstants.ODPS);
+    }
 
     public void setFrom(SQLSubqueryTableSource from) {
         this.from = from;

src/main/java/com/alibaba/druid/sql/dialect/odps/ast/OdpsShowPartitionsStmt.java

@@ -5,10 +5,15 @@ import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.dialect.odps.visitor.OdpsASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OdpsShowPartitionsStmt extends SQLStatementImpl implements SQLStatement {
 
     private SQLExprTableSource tableSource;
+    
+    public OdpsShowPartitionsStmt() {
+        super (JdbcConstants.ODPS);
+    }
 
     public SQLExprTableSource getTableSource() {
         return tableSource;

src/main/java/com/alibaba/druid/sql/dialect/odps/ast/OdpsShowStatisticStmt.java

@@ -5,10 +5,15 @@ import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.ast.statement.SQLExprTableSource;
 import com.alibaba.druid.sql.dialect.odps.visitor.OdpsASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OdpsShowStatisticStmt extends SQLStatementImpl implements SQLStatement {
 
     private SQLExprTableSource tableSource;
+    
+    public OdpsShowStatisticStmt() {
+        super (JdbcConstants.ODPS);
+    }
 
     public SQLExprTableSource getTableSource() {
         return tableSource;

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

@@ -18,11 +18,16 @@ package com.alibaba.druid.sql.dialect.oracle.ast.stmt;
 import com.alibaba.druid.sql.ast.statement.SQLAlterTableStatement;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleAlterTableStatement extends SQLAlterTableStatement implements OracleDDLStatement {
 
     private boolean updateGlobalIndexes     = false;
     private boolean invalidateGlobalIndexes = false;
+    
+    public OracleAlterTableStatement() {
+        super (JdbcConstants.ORACLE);
+    }
 
     protected void accept0(SQLASTVisitor visitor) {
         accept0((OracleASTVisitor) visitor);

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

@@ -20,6 +20,7 @@ import com.alibaba.druid.sql.ast.SQLName;
 import com.alibaba.druid.sql.ast.statement.SQLCreateIndexStatement;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleCreateIndexStatement extends SQLCreateIndexStatement implements OracleDDLStatement {
 
@@ -41,6 +42,10 @@ public class OracleCreateIndexStatement extends SQLCreateIndexStatement implemen
     private Boolean enable            = null;
 
     private boolean computeStatistics = false;
+    
+    public OracleCreateIndexStatement() {
+        super (JdbcConstants.ORACLE);
+    }
 
     public SQLName getTablespace() {
         return tablespace;

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

@@ -24,6 +24,7 @@ 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.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleCreateTableStatement extends SQLCreateTableStatement implements OracleDDLStatement {
 
@@ -58,6 +59,10 @@ public class OracleCreateTableStatement extends SQLCreateTableStatement implemen
     private SQLPartitioningClause   partitioning;
 
     private DeferredSegmentCreation deferredSegmentCreation;
+    
+    public OracleCreateTableStatement() {
+        super (JdbcConstants.ORACLE);
+    }
 
     public OracleLobStorageClause getLobStorage() {
         return lobStorage;

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

@@ -23,6 +23,7 @@ import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
 import com.alibaba.druid.sql.dialect.oracle.ast.clause.OracleReturningClause;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleDeleteStatement extends SQLDeleteStatement {
 
@@ -32,7 +33,7 @@ public class OracleDeleteStatement extends SQLDeleteStatement {
     private OracleReturningClause returning = null;
 
     public OracleDeleteStatement(){
-
+        super (JdbcConstants.ORACLE);
     }
 
     public OracleReturningClause getReturning() {

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

@@ -21,11 +21,16 @@ import com.alibaba.druid.sql.ast.expr.SQLCharExpr;
 import com.alibaba.druid.sql.ast.statement.SQLExplainStatement;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleExplainStatement extends SQLExplainStatement implements OracleStatement {
 
     private SQLCharExpr statementId;
     private SQLExpr     into;
+    
+    public OracleExplainStatement() {
+        super (JdbcConstants.ORACLE);
+    }
 
     @Override
     public void accept0(OracleASTVisitor visitor) {

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

@@ -19,8 +19,13 @@ import com.alibaba.druid.sql.SQLUtils;
 import com.alibaba.druid.sql.ast.SQLStatementImpl;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public abstract class OracleStatementImpl extends SQLStatementImpl implements OracleStatement {
+    
+    public OracleStatementImpl() {
+        super(JdbcConstants.ORACLE);
+    }
 
     protected void accept0(SQLASTVisitor visitor) {
         accept0((OracleASTVisitor) visitor);

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

@@ -23,6 +23,7 @@ import com.alibaba.druid.sql.ast.SQLHint;
 import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleUpdateStatement extends SQLUpdateStatement implements OracleStatement {
 
@@ -35,7 +36,7 @@ public class OracleUpdateStatement extends SQLUpdateStatement implements OracleS
     private List<SQLExpr>       returningInto = new ArrayList<SQLExpr>();
 
     public OracleUpdateStatement(){
-
+        super (JdbcConstants.ORACLE);
     }
 
     public List<SQLExpr> getReturning() {

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

@@ -105,6 +105,7 @@ import com.alibaba.druid.sql.parser.Lexer;
 import com.alibaba.druid.sql.parser.ParserException;
 import com.alibaba.druid.sql.parser.SQLStatementParser;
 import com.alibaba.druid.sql.parser.Token;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class OracleStatementParser extends SQLStatementParser {
 
@@ -163,7 +164,8 @@ public class OracleStatementParser extends SQLStatementParser {
             }
 
             if (lexer.token() == (Token.SELECT)) {
-                statementList.add(new SQLSelectStatement(new OracleSelectParser(this.exprParser).select()));
+                SQLSelectStatement stmt = new SQLSelectStatement(new OracleSelectParser(this.exprParser).select(), JdbcConstants.ORACLE); 
+                statementList.add(stmt);
                 continue;
             }
 
@@ -238,7 +240,7 @@ public class OracleStatementParser extends SQLStatementParser {
                 if (variant instanceof SQLBinaryOpExpr) {
                     SQLBinaryOpExpr binaryOpExpr = (SQLBinaryOpExpr) variant;
                     if (binaryOpExpr.getOperator() == SQLBinaryOperator.Assignment) {
-                        SQLSetStatement stmt = new SQLSetStatement(binaryOpExpr.getLeft(), binaryOpExpr.getRight());
+                        SQLSetStatement stmt = new SQLSetStatement(binaryOpExpr.getLeft(), binaryOpExpr.getRight(), getDbType());
                         statementList.add(stmt);
                         continue;
                     }
@@ -246,7 +248,7 @@ public class OracleStatementParser extends SQLStatementParser {
                 accept(Token.COLONEQ);
                 SQLExpr value = this.exprParser.expr();
 
-                SQLSetStatement stmt = new SQLSetStatement(variant, value);
+                SQLSetStatement stmt = new SQLSetStatement(variant, value, getDbType());
                 statementList.add(stmt);
                 continue;
             }

src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGDeleteStatement.java

@@ -23,6 +23,7 @@ import com.alibaba.druid.sql.ast.statement.SQLDeleteStatement;
 import com.alibaba.druid.sql.dialect.postgresql.ast.PGWithClause;
 import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class PGDeleteStatement extends SQLDeleteStatement implements PGSQLStatement {
 
@@ -31,6 +32,10 @@ public class PGDeleteStatement extends SQLDeleteStatement implements PGSQLStatem
     private List<SQLName> using = new ArrayList<SQLName>(2);
     private boolean       returning;
     private String        alias;
+    
+    public PGDeleteStatement() {
+        super (JdbcConstants.POSTGRESQL);
+    }
 
     public boolean isReturning() {
         return returning;

src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGSelectStatement.java

@@ -20,16 +20,18 @@ import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
 import com.alibaba.druid.sql.dialect.postgresql.ast.PGWithClause;
 import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class PGSelectStatement extends SQLSelectStatement implements PGSQLStatement {
 
     private PGWithClause with;
 
     public PGSelectStatement(){
+        super(JdbcConstants.POSTGRESQL);
     }
 
     public PGSelectStatement(SQLSelect select){
-        super(select);
+        super(select, JdbcConstants.POSTGRESQL);
     }
 
     public PGWithClause getWith() {

src/main/java/com/alibaba/druid/sql/dialect/postgresql/ast/stmt/PGUpdateStatement.java

@@ -24,6 +24,7 @@ import com.alibaba.druid.sql.ast.statement.SQLUpdateStatement;
 import com.alibaba.druid.sql.dialect.postgresql.ast.PGWithClause;
 import com.alibaba.druid.sql.dialect.postgresql.visitor.PGASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class PGUpdateStatement extends SQLUpdateStatement implements PGSQLStatement {
 
@@ -34,6 +35,10 @@ public class PGUpdateStatement extends SQLUpdateStatement implements PGSQLStatem
     private List<SQLExpr>  returning = new ArrayList<SQLExpr>(2);
 
     private SQLTableSource from;
+    
+    public PGUpdateStatement(){
+        super (JdbcConstants.POSTGRESQL);
+    }
 
     public SQLTableSource getFrom() {
         return from;

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

@@ -22,12 +22,17 @@ import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerStatement;
 import com.alibaba.druid.sql.dialect.sqlserver.ast.SQLServerTop;
 import com.alibaba.druid.sql.dialect.sqlserver.visitor.SQLServerASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+import com.alibaba.druid.util.JdbcConstants;
 
 public class SQLServerUpdateStatement extends SQLUpdateStatement implements SQLServerStatement {
 
     private SQLServerTop    top;
     private SQLTableSource  from;
     private SQLServerOutput output;
+    
+    public SQLServerUpdateStatement(){
+        super (JdbcConstants.SQL_SERVER);
+    }
 
     public SQLServerTop getTop() {
         return top;

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

@@ -355,7 +355,7 @@ public class SQLServerStatementParser extends SQLStatementParser {
         }
 
         if (lexer.token() == Token.VARIANT) {
-            SQLSetStatement stmt = new SQLSetStatement();
+            SQLSetStatement stmt = new SQLSetStatement(getDbType());
             parseAssignItems(stmt.getItems(), stmt);
             return stmt;
         } else {