support sql ast object toString

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

@@ -26,6 +26,14 @@ public class SQLAlterTableStatement extends SQLStatementImpl implements SQLDDLSt
 
     private SQLExprTableSource      tableSource;
     private List<SQLAlterTableItem> items = new ArrayList<SQLAlterTableItem>();
+    
+    public SQLAlterTableStatement() {
+        
+    }
+    
+    public SQLAlterTableStatement(String dbType) {
+        super (dbType);
+    }
 
     public List<SQLAlterTableItem> getItems() {
         return items;

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

@@ -33,6 +33,14 @@ public class SQLCallStatement extends SQLStatementImpl {
     private SQLName             procedureName;
 
     private final List<SQLExpr> parameters = new ArrayList<SQLExpr>();
+    
+    public SQLCallStatement() {
+        
+    }
+    
+    public SQLCallStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLVariantRefExpr getOutParameter() {
         return outParameter;

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

@@ -33,6 +33,10 @@ public class SQLCreateDatabaseStatement extends SQLStatementImpl {
 
     public SQLCreateDatabaseStatement(){
     }
+    
+    public SQLCreateDatabaseStatement(String dbType){
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -35,6 +35,10 @@ public class SQLCreateIndexStatement extends SQLStatementImpl implements SQLDDLS
     public SQLCreateIndexStatement(){
 
     }
+    
+    public SQLCreateIndexStatement(String dbType){
+        super (dbType);
+    }
 
     public SQLTableSource getTable() {
         return table;

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

@@ -33,6 +33,10 @@ public class SQLCreateTableStatement extends SQLStatementImpl implements SQLDDLS
     public SQLCreateTableStatement(){
 
     }
+    
+    public SQLCreateTableStatement(String dbType){
+        super (dbType);
+    }
 
     public SQLName getName() {
         if (tableSource == null) {

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

@@ -37,6 +37,14 @@ public class SQLCreateTriggerStatement extends SQLStatementImpl {
     private boolean                  forEachRow    = false;
 
     private SQLStatement             body;
+    
+    public SQLCreateTriggerStatement() {
+        
+    }
+    
+    public SQLCreateTriggerStatement(String dbType) {
+        super (dbType);
+    }
 
     protected void accept0(SQLASTVisitor visitor) {
         if (visitor.visit(this)) {

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

@@ -36,6 +36,10 @@ public class SQLCreateViewStatement extends SQLStatementImpl implements SQLDDLSt
     public SQLCreateViewStatement(){
 
     }
+    
+    public SQLCreateViewStatement(String dbType){
+        super (dbType);
+    }
 
     public boolean isOrReplace() {
         return orReplace;

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

@@ -29,6 +29,10 @@ public class SQLDeleteStatement extends SQLStatementImpl {
     public SQLDeleteStatement(){
 
     }
+    
+    public SQLDeleteStatement(String dbType){
+        super (dbType);
+    }
 
     public SQLTableSource getTableSource() {
         return tableSource;

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

@@ -23,6 +23,14 @@ public class SQLDropDatabaseStatement extends SQLStatementImpl implements SQLDDL
 
     private SQLExpr database;
     private boolean ifExists;
+    
+    public SQLDropDatabaseStatement() {
+        
+    }
+    
+    public SQLDropDatabaseStatement(String dbType) {
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -23,6 +23,14 @@ public class SQLDropFunctionStatement extends SQLStatementImpl implements SQLDDL
 
     private SQLName name;
     private boolean ifExists;
+    
+    public SQLDropFunctionStatement() {
+        
+    }
+    
+    public SQLDropFunctionStatement(String dbType) {
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -23,6 +23,14 @@ public class SQLDropIndexStatement extends SQLStatementImpl implements SQLDDLSta
 
     private SQLExpr            indexName;
     private SQLExprTableSource tableName;
+    
+    public SQLDropIndexStatement() {
+        
+    }
+    
+    public SQLDropIndexStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLExpr getIndexName() {
         return indexName;

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

@@ -23,6 +23,14 @@ public class SQLDropProcedureStatement extends SQLStatementImpl implements SQLDD
 
     private SQLName name;
     private boolean ifExists;
+    
+    public SQLDropProcedureStatement() {
+        
+    }
+    
+    public SQLDropProcedureStatement(String dbType) {
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -22,6 +22,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLDropSequenceStatement extends SQLStatementImpl implements SQLDDLStatement {
 
     private SQLName name;
+    
+    public SQLDropSequenceStatement() {
+        
+    }
+    
+    public SQLDropSequenceStatement(String dbType) {
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -23,6 +23,14 @@ public class SQLDropTableSpaceStatement extends SQLStatementImpl implements SQLD
 
     private SQLName name;
     private boolean ifExists;
+    
+    public SQLDropTableSpaceStatement() {
+        
+    }
+    
+    public SQLDropTableSpaceStatement(String dbType) {
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -36,12 +36,25 @@ public class SQLDropTableStatement extends SQLStatementImpl implements SQLDDLSta
     public SQLDropTableStatement(){
 
     }
-
-    public SQLDropTableStatement(SQLName name){
-        this(new SQLExprTableSource(name));
+    
+    public SQLDropTableStatement(String dbType){
+        super (dbType);
     }
 
+    public SQLDropTableStatement(SQLName name, String dbType){
+        this(new SQLExprTableSource(name), dbType);
+    }
+    
+    public SQLDropTableStatement(SQLName name){
+        this (name, null);
+    }
+    
     public SQLDropTableStatement(SQLExprTableSource tableSource){
+        this (tableSource, null);
+    }
+
+    public SQLDropTableStatement(SQLExprTableSource tableSource, String dbType){
+        this (dbType);
         this.tableSources.add(tableSource);
     }
 

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

@@ -22,6 +22,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLDropTriggerStatement extends SQLStatementImpl implements SQLDDLStatement {
 
     private SQLName name;
+    
+    public SQLDropTriggerStatement() {
+        
+    }
+    
+    public SQLDropTriggerStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLName getName() {
         return name;

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

@@ -25,6 +25,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLDropUserStatement extends SQLStatementImpl implements SQLDDLStatement {
 
     private List<SQLExpr> users = new ArrayList<SQLExpr>(2);
+    
+    public SQLDropUserStatement() {
+        
+    }
+    
+    public SQLDropUserStatement(String dbType) {
+        super (dbType);
+    }
 
     public List<SQLExpr> getUsers() {
         return users;

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

@@ -33,6 +33,10 @@ public class SQLDropViewStatement extends SQLStatementImpl implements SQLDDLStat
     public SQLDropViewStatement(){
 
     }
+    
+    public SQLDropViewStatement(String dbType){
+        super (dbType);
+    }
 
     public SQLDropViewStatement(SQLName name){
         this(new SQLExprTableSource(name));

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

@@ -27,6 +27,14 @@ public class SQLExplainStatement extends SQLStatementImpl {
     protected SQLStatement       statement;
 
     private List<SQLCommentHint> hints;
+    
+    public SQLExplainStatement() {
+        
+    }
+    
+    public SQLExplainStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLStatement getStatement() {
         return statement;

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

@@ -28,6 +28,14 @@ public class SQLGrantStatement extends SQLStatementImpl {
 
     private SQLExpr             on;
     private SQLExpr             to;
+    
+    public SQLGrantStatement() {
+        
+    }
+    
+    public SQLGrantStatement(String dbType) {
+        super (dbType);
+    }
 
     // mysql
     private ObjectType          objectType;

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

@@ -22,6 +22,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLReleaseSavePointStatement extends SQLStatementImpl {
 
     private SQLExpr name;
+    
+    public SQLReleaseSavePointStatement() {
+        
+    }
+    
+    public SQLReleaseSavePointStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLExpr getName() {
         return name;

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

@@ -22,6 +22,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLRollbackStatement extends SQLStatementImpl {
 
     private SQLName to;
+    
+    public SQLRollbackStatement() {
+        
+    }
+    
+    public SQLRollbackStatement(String dbType) {
+        super (dbType);
+    }
 
     @Override
     protected void accept0(SQLASTVisitor visitor) {

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

@@ -22,6 +22,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLSavePointStatement extends SQLStatementImpl {
 
     private SQLExpr name;
+    
+    public SQLSavePointStatement() {
+        
+    }
+    
+    public SQLSavePointStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLExpr getName() {
         return name;

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

@@ -26,10 +26,19 @@ public class SQLSelectStatement extends SQLStatementImpl {
 
     }
 
+    public SQLSelectStatement(String dbType){
+        super (dbType);
+    }
+
     public SQLSelectStatement(SQLSelect select){
         this.setSelect(select);
     }
 
+    public SQLSelectStatement(SQLSelect select, String dbType){
+        this(dbType);
+        this.setSelect(select);
+    }
+
     public SQLSelect getSelect() {
         return this.select;
     }

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

@@ -31,8 +31,17 @@ public class SQLSetStatement extends SQLStatementImpl {
 
     public SQLSetStatement(){
     }
-
+    
+    public SQLSetStatement(String dbType){
+        super (dbType);
+    }
+    
     public SQLSetStatement(SQLExpr target, SQLExpr value){
+        this(target, value, null);
+    }
+
+    public SQLSetStatement(SQLExpr target, SQLExpr value, String dbType){
+        super (dbType);
         this.items.add(new SQLAssignItem(target, value));
     }
 

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

@@ -31,6 +31,14 @@ public class SQLTruncateStatement extends SQLStatementImpl {
     private boolean                    only;
     private Boolean                    restartIdentity;
     private Boolean                    cascade;
+    
+    public SQLTruncateStatement() {
+        
+    }
+    
+    public SQLTruncateStatement(String dbType) {
+        super (dbType);
+    }
 
     public List<SQLExprTableSource> getTableSources() {
         return tableSources;

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

@@ -33,6 +33,10 @@ public class SQLUpdateStatement extends SQLStatementImpl {
     public SQLUpdateStatement(){
 
     }
+    
+    public SQLUpdateStatement(String dbType){
+        super (dbType);
+    }
 
     public SQLTableSource getTableSource() {
         return tableSource;

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

@@ -23,6 +23,14 @@ import com.alibaba.druid.sql.visitor.SQLASTVisitor;
 public class SQLUseStatement extends SQLStatementImpl implements SQLStatement {
 
     private SQLName database;
+    
+    public SQLUseStatement() {
+        
+    }
+    
+    public SQLUseStatement(String dbType) {
+        super (dbType);
+    }
 
     public SQLName getDatabase() {
         return database;