Add Utf8View to TypeCategory::Unknown (#13350)

* add utf8view

Signed-off-by: jayzhan211 <[email protected]>

* add test

Signed-off-by: jayzhan211 <[email protected]>

* fix comment

Signed-off-by: Jay Zhan <[email protected]>

---------

Signed-off-by: jayzhan211 <[email protected]>
Signed-off-by: Jay Zhan <[email protected]>

Author: jayzhan211

datafusion/expr-common/src/type_coercion/binary.rs

@@ -330,11 +330,13 @@ impl From<&DataType> for TypeCategory {
                     return TypeCategory::Array;
                 }
 
-                // String literal is possible to cast to many other types like numeric or datetime,
-                // therefore, it is categorized as a unknown type
+                // It is categorized as unknown type because the type will be resolved later on
                 if matches!(
                     data_type,
-                    DataType::Utf8 | DataType::LargeUtf8 | DataType::Null
+                    DataType::Utf8
+                        | DataType::LargeUtf8
+                        | DataType::Utf8View
+                        | DataType::Null
                 ) {
                     return TypeCategory::Unknown;
                 }

datafusion/sqllogictest/test_files/coalesce.slt

@@ -242,6 +242,14 @@ none_set
 statement ok
 drop table test1
 
+# coalesce with utf8view
+query TTT
+select coalesce(arrow_cast(null, 'Utf8View'), arrow_cast('t', 'Utf8')),
+       arrow_typeof(coalesce(arrow_cast(null, 'Utf8View'), arrow_cast('t', 'Utf8'))),
+       arrow_typeof(coalesce(arrow_cast(null, 'Utf8'), arrow_cast('t', 'Utf8View')));
+----
+t Utf8View Utf8View
+
 # test dict coercion with value
 statement ok
 create table t(c varchar) as values ('a'), (null);