affected rows count for insert (#18)

Author: YaroslavLitvinov

datafusion_iceberg/src/table.rs

@@ -788,14 +788,16 @@ impl DataSink for IcebergDataSink {
             write_parquet_partitioned(table, data.map_err(Into::into), self.0.branch.as_deref())
                 .await?;
 
+        let count = metadata_files.iter().map(|x|x.record_count()).fold(0, |acc, x| acc+ x);
+
         table
             .new_transaction(self.0.branch.as_deref())
             .append_data(metadata_files)
             .commit()
             .await
             .map_err(DataFusionIcebergError::from)?;
 
-        Ok(0)
+        Ok(count as u64)
     }
     fn metrics(&self) -> Option<MetricsSet> {
         None
@@ -1196,7 +1198,7 @@ mod tests {
 
         ctx.register_table("orders", table.clone()).unwrap();
 
-        ctx.sql(
+        let res = ctx.sql(
             "INSERT INTO orders (id, customer_id, product_id, date, amount) VALUES 
                 (1, 1, 1, '2020-01-01', 1),
                 (2, 2, 1, '2020-01-01', 1),
@@ -1211,6 +1213,14 @@ mod tests {
         .await
         .expect("Failed to insert values into table");
 
+        let count = res[0]
+            .column(0)
+            .as_any()
+            .downcast_ref::<Int64Array>()
+            .unwrap()
+            .values()[0];
+        assert_eq!(count, 6);
+
         let batches = ctx
             .sql("select product_id, sum(amount) from orders where customer_id = 1 group by product_id;")
             .await