Add more DataFrame operations examples (#599)

Author: usmanmohammed

examples/Microsoft.Spark.CSharp.Examples/Sql/Batch/Basic.cs

@@ -108,6 +108,25 @@ public void Run(string[] args)
 
             DataFrame joinedDf3 = df.Join(df, df["name"] == df["name"], "outer");
             joinedDf3.Show();
+            
+            // Union of two data frames
+            DataFrame unionDf = df.Union(df);
+            unionDf.Show();
+
+            // Add new column to data frame
+            df.WithColumn("location", Lit("Seattle")).Show();
+
+            // Rename existing column
+            df.WithColumnRenamed("name", "fullname").Show();
+
+            // Filter rows with null age
+            df.Filter(Col("age").IsNull()).Show();
+
+            // Fill null values in age column with -1
+            df.Na().Fill(-1, new[] { "age" }).Show();
+
+            // Drop age column
+            df.Drop(new[] { "age" }).Show();
 
             spark.Stop();
         }

examples/Microsoft.Spark.FSharp.Examples/Sql/Basic.fs

@@ -78,6 +78,25 @@ type Basic() =
 
             let joinedDf3 = df.Join(df, df.["name"].EqualTo(df.["name"]), "outer")
             joinedDf3.Show()
+            
+            // Union of two data frames
+            let unionDf = df.Union(df)
+            unionDf.Show()
+
+            // Add new column to data frame
+            df.WithColumn("location", Functions.Lit("Seattle")).Show()
+
+            // Rename existing column
+            df.WithColumnRenamed("name", "fullname").Show()
+
+            // Filter rows with null age
+            df.Filter(df.["age"].IsNull()).Show()
+
+            // Fill null values in age column with -1
+            df.Na().Fill(-1L, ["age"]).Show()
+
+            // Drop age column
+            df.Drop(df.["age"]).Show()
 
             spark.Stop()
             0