change

src/connector/nodejs/nodetaos/cinterface.js

@@ -367,12 +367,16 @@ CTaosInterface.prototype.fetchBlock = function fetchBlock(result, fields) {
   let offset = 0;
   for (let i = 0; i < fields.length; i++) {
     pdata = ref.reinterpret(pblock,8,i*8);
+	if(ref.isNull(pdata.readPointer())){
+		blocks[i] = new Array();
+	}else{
     	pdata = ref.ref(pdata.readPointer());
     	if (!convertFunctions[fields[i]['type']] ) {
       		throw new errors.DatabaseError("Invalid data type returned from database");
    		}
     	blocks[i] = convertFunctions[fields[i]['type']](pdata, 1, fieldlens[i], offset, isMicro);
 	}
+  }
   return {blocks: blocks, num_of_rows:Math.abs(num_of_rows)}
 }
 CTaosInterface.prototype.fetchRow = function fetchRow(result, fields) {
@@ -437,6 +441,9 @@ CTaosInterface.prototype.fetch_rows_a = function fetch_rows_a(result, callback,
     }
     if (numOfRows2 > 0){
       for (let i = 0; i < fields.length; i++) {
+		if(ref.isNull(pdata.readPointer())){
+			blocks[i] = new Array();
+		}else{
 			if (!convertFunctions[fields[i]['type']] ) { 
           		throw new errors.DatabaseError("Invalid data type returned from database");
         	}   
@@ -447,6 +454,7 @@ CTaosInterface.prototype.fetch_rows_a = function fetch_rows_a(result, callback,
         	//offset += fields[i]['bytes'] * numOfRows2;
 		}		
       }
+    }
     callback(param2, result2, numOfRows2, blocks);
   }
   asyncCallbackWrapper = ffi.Callback(ref.types.void, [ ref.types.void_ptr, ref.types.void_ptr, ref.types.int ], asyncCallbackWrapper);