Fix doc problem (#3094)

lhw362950217 · web-flow · commit d3907ac1fab8 · 2020-11-06T14:22:21.000+08:00
diff --git a/doc/tutorial/iris-dnn.cn.md b/doc/tutorial/iris-dnn.cn.md
@@ -36,7 +36,7 @@ select * from iris.train limit 5;
 
 我们在本节中训练一个三分类的DNNClassifier，它包含两个隐藏层，每层10个节点。使用SQLFlow扩展语法提供的模型训练子句，我们可以很容易地指定模型结构：
 
-```sql
+```
 TO TRAIN DNNClassifier
 WITH
   model.n_classes = 3,
diff --git a/doc/tutorial/iris-dnn.md b/doc/tutorial/iris-dnn.md
@@ -36,7 +36,7 @@ select * from iris.train limit 5;
 
 Let's train a ternary DNNClassifier, which has two hidden layers with ten hidden units each. This can be done by specifying the training clause for SQLFlow's extended syntax.
 
-```sql
+```
 TO TRAIN DNNClassifier
 WITH
   model.n_classes = 3,
