Update datafusion/core/src/dataframe/mod.rs

Co-authored-by: Andrew Lamb <[email protected]>

Author: Weijun-H

datafusion/core/src/dataframe/mod.rs

@@ -534,7 +534,7 @@ impl DataFrame {
                 vec![],
                 original_schema_fields
                     .clone()
-                    .map(|f| count_null(col(f.name())).alias(f.name()))
+                    .map(|f| count(col(f.name()).is_null()).alias(f.name())))
                     .collect::<Vec<_>>(),
             ),
             // mean aggregation