feat: Support TimestampNanosecond in CASE

Author: MazterQyou

datafusion/physical-expr/src/expressions/case.rs

@@ -21,7 +21,7 @@ use crate::expressions::try_cast;
 use crate::PhysicalExpr;
 use arrow::array::{self, *};
 use arrow::compute::{and, cast, eq_dyn, is_null, not, or, or_kleene};
-use arrow::datatypes::{DataType, Schema};
+use arrow::datatypes::{DataType, Schema, TimeUnit};
 use arrow::record_batch::RecordBatch;
 use datafusion_common::{DataFusionError, Result};
 use datafusion_expr::{binary_rule::coerce_types, ColumnarValue, Operator};
@@ -254,6 +254,13 @@ fn if_then_else(
             true_values,
             false_values
         ),
+        DataType::Timestamp(TimeUnit::Nanosecond, None) => if_then_else!(
+            array::TimestampNanosecondBuilder,
+            array::TimestampNanosecondArray,
+            bools,
+            true_values,
+            false_values
+        ),
         other => Err(DataFusionError::Execution(format!(
             "CASE does not support '{:?}'",
             other