improved sql parser.

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

@@ -15,6 +15,7 @@
  */
 package com.alibaba.druid.sql.dialect.oracle.ast;
 
+import com.alibaba.druid.sql.ast.SQLDataType;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLObjectImpl;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
@@ -36,4 +37,8 @@ public abstract class OracleSQLObjectImpl extends SQLObjectImpl implements Oracl
     public OracleSQLObject clone() {
         throw new UnsupportedOperationException();
     }
+
+    public SQLDataType computeDataType() {
+        return null;
+    }
 }

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

@@ -15,6 +15,7 @@
  */
 package com.alibaba.druid.sql.dialect.oracle.ast.expr;
 
+import com.alibaba.druid.sql.ast.SQLDataType;
 import com.alibaba.druid.sql.ast.SQLOver;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;
 import com.alibaba.druid.sql.visitor.SQLASTVisitor;
@@ -60,4 +61,8 @@ public class OracleAnalytic extends SQLOver implements OracleExpr {
     public void setWindowing(OracleAnalyticWindowing windowing) {
         this.windowing = windowing;
     }
+
+    public SQLDataType computeDataType() {
+        return null;
+    }
 }

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

@@ -15,6 +15,7 @@
  */
 package com.alibaba.druid.sql.dialect.oracle.ast.expr;
 
+import com.alibaba.druid.sql.ast.SQLDataType;
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.dialect.oracle.ast.OracleSQLObjectImpl;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleASTVisitor;