fix(query): interval type support cast to string

src/query/expression/src/utils/display.rs

@@ -229,7 +229,7 @@ impl Display for ScalarRef<'_> {
             ScalarRef::String(s) => write!(f, "'{s}'"),
             ScalarRef::Timestamp(t) => write!(f, "'{}'", timestamp_to_string(*t, &TimeZone::UTC)),
             ScalarRef::Date(d) => write!(f, "'{}'", date_to_string(*d as i64, &TimeZone::UTC)),
-            ScalarRef::Interval(interval) => write!(f, "{}", interval_to_string(interval)),
+            ScalarRef::Interval(interval) => write!(f, "'{}'", interval_to_string(interval)),
             ScalarRef::Array(col) => write!(f, "[{}]", col.iter().join(", ")),
             ScalarRef::Map(col) => {
                 write!(f, "{{")?;

src/query/functions/src/cast_rules.rs

@@ -87,6 +87,7 @@ pub const GENERAL_CAST_RULES: AutoCastRules = &[
     (DataType::String, DataType::Binary),
     (DataType::String, DataType::Timestamp),
     (DataType::String, DataType::Date),
+    (DataType::String, DataType::Interval),
     (DataType::String, DataType::Boolean),
     (DataType::Date, DataType::Timestamp),
     (

src/query/functions/src/scalars/timestamp/src/interval.rs

@@ -12,14 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::io::Write;
+
 use databend_common_column::types::months_days_micros;
 use databend_common_expression::date_helper::EvalMonthsImpl;
 use databend_common_expression::error_to_null;
 use databend_common_expression::types::interval::interval_to_string;
 use databend_common_expression::types::interval::string_to_interval;
 use databend_common_expression::types::Int64Type;
 use databend_common_expression::types::IntervalType;
-use databend_common_expression::types::NullableType;
 use databend_common_expression::types::StringType;
 use databend_common_expression::types::TimestampType;
 use databend_common_expression::vectorize_with_builder_1_arg;
@@ -75,15 +76,13 @@ fn register_string_to_interval(registry: &mut FunctionRegistry) {
 }
 
 fn register_interval_to_string(registry: &mut FunctionRegistry) {
-    registry.register_combine_nullable_1_arg::<IntervalType, StringType, _, _>(
+    registry.register_passthrough_nullable_1_arg::<IntervalType, StringType, _, _>(
         "to_string",
-        |_, _| FunctionDomain::MayThrow,
-        vectorize_with_builder_1_arg::<IntervalType, NullableType<StringType>>(
-            |interval, output, _| {
-                let res = interval_to_string(&interval).to_string();
-                output.push(&res);
-            },
-        ),
+        |_, _| FunctionDomain::Full,
+        vectorize_with_builder_1_arg::<IntervalType, StringType>(|interval, output, _| {
+            write!(output.row_buffer, "{}", interval_to_string(&interval)).unwrap();
+            output.commit_row();
+        }),
     );
 }
 

src/query/functions/tests/it/scalars/testdata/function_list.txt

@@ -3931,7 +3931,7 @@ Functions overloads:
 34 to_string(Bitmap NULL) :: String NULL
 35 to_string(Geometry) :: String
 36 to_string(Geometry NULL) :: String NULL
-37 to_string(Interval) :: String NULL
+37 to_string(Interval) :: String
 38 to_string(Interval NULL) :: String NULL
 0 to_timestamp(Variant) :: Timestamp
 1 to_timestamp(Variant NULL) :: Timestamp NULL

tests/sqllogictests/suites/query/functions/02_0079_function_interval.test

@@ -25,6 +25,12 @@ select * from t where c1 > to_interval('-1 year');
 ----
 -1 month -1:00:00 0:00:00.001
 
+onlyif http
+query TT
+select * from t where c1 > '-1 year';
+----
+-1 month -1:00:00 0:00:00.001
+
 onlyif http
 statement error 1006
 select to_interval('1 month 1 hour ago 1 micros');
@@ -184,3 +190,9 @@ query T
 select '2022-01-01'::timestamp-'2021-12-01'::timestamp;
 ----
 2678400000000
+
+onlyif http
+query TT
+select '1 days'::INTERVAL::String, '11 days'::INTERVAL::String;
+----
+1 day 11 days