[fix](cast) fix wrong result of casting empty string to array date (#22281)

be/src/vec/data_types/data_type_time_v2.cpp

@@ -67,12 +67,6 @@ void DataTypeDateV2::to_string(const IColumn& column, size_t row_num, BufferWrit
 
     UInt32 int_val = assert_cast<const ColumnUInt32&>(*ptr).get_element(row_num);
     DateV2Value<DateV2ValueType> val = binary_cast<UInt32, DateV2Value<DateV2ValueType>>(int_val);
-    // if this is an invalid date, write nothing(instead of 0000-00-00) to output string, or else
-    // it will cause problem for null DataTypeDateV2 value in cast function,
-    // e.g. cast(cast(null_date as char) as date)
-    if (!val.is_valid_date()) {
-        return;
-    }
 
     char buf[64];
     char* pos = val.to_string(buf);
@@ -150,12 +144,6 @@ void DataTypeDateTimeV2::to_string(const IColumn& column, size_t row_num,
     UInt64 int_val = assert_cast<const ColumnUInt64&>(*ptr).get_element(row_num);
     DateV2Value<DateTimeV2ValueType> val =
             binary_cast<UInt64, DateV2Value<DateTimeV2ValueType>>(int_val);
-    // if this is an invalid date, write nothing(instead of 0000-00-00) to output string, or else
-    // it will cause problem for null DataTypeDateV2 value in cast function,
-    // e.g. cast(cast(null_date as char) as date)
-    if (!val.is_valid_date()) {
-        return;
-    }
 
     char buf[64];
     char* pos = val.to_string(buf, _scale);

be/src/vec/runtime/vdatetime_value.cpp

@@ -2406,6 +2406,12 @@ bool DateV2Value<T>::from_date_format_str(const char* format, int format_len, co
 
 template <typename T>
 int32_t DateV2Value<T>::to_buffer(char* buffer, int scale) const {
+    // if this is an invalid date, write nothing(instead of 0000-00-00) to output string, or else
+    // it will cause problem for null DataTypeDateV2 value in cast function,
+    // e.g. cast(cast(null_date as char) as date)
+    if (!is_valid_date()) {
+        return 0;
+    }
     char* start = buffer;
     uint32_t temp;
     // Year

regression-test/data/query_p0/sql_functions/cast_function/test_cast_string_to_array.out

@@ -30,5 +30,20 @@
 [1.340, 2.010, 0.000, 0.000, 0.000]
 
 -- !sql --
-[2022-09-01, 0000-00-00, 0000-00-00]
+[2022-09-01, , ]
+
+-- !sql --
+["2022-09-01", "", ""]
+
+-- !sql --
+[2022-09-01, NULL, NULL]
+
+-- !sql --
+[2022-09-01, , ]
+
+-- !sql --
+["2022-09-01", "", ""]
+
+-- !sql --
+[2022-09-01, NULL, NULL]
 

regression-test/suites/query_p0/sql_functions/cast_function/test_cast_string_to_array.groovy

@@ -41,5 +41,14 @@ suite("test_cast_string_to_array") {
     qt_sql """ select cast ("[1,2,3,,,]" as array<int>) """
     qt_sql """ select cast ("[a,b,c,,,]" as array<string>) """
     qt_sql """ select cast ("[1.34,2.01,,,]" as array<decimal(10, 3)>) """
+
+    sql """ ADMIN SET FRONTEND CONFIG ("enable_date_conversion" = "false"); """
     qt_sql """ select cast ("[2022-09-01,,]" as array<date>) """
+    qt_sql """ select cast ("[2022-09-01,,]" as array<string>) """
+    qt_sql """ select cast(cast ("[2022-09-01,,]" as array<string>) as array<date>) """
+
+    sql """ ADMIN SET FRONTEND CONFIG ("enable_date_conversion" = "true"); """
+    qt_sql """ select cast ("[2022-09-01,,]" as array<date>) """
+    qt_sql """ select cast ("[2022-09-01,,]" as array<string>) """
+    qt_sql """ select cast(cast ("[2022-09-01,,]" as array<string>) as array<date>) """
 }