{ “title”: “CAST”, “language”: “en” }

CAST

Description

Syntax

T cast (input as Type)

Converts input to the specified type

example

  1. Turn constant, or a column in a table
mysql> select cast (1 as BIGINT);
+-------------------+
| CAST(1 AS BIGINT) |
+-------------------+
|                 1 |
+-------------------+
  1. Transferred raw data
curl --location-trusted -u root: -T ~/user_data/bigint -H "columns: tmp_k1, k1=cast(tmp_k1 as BIGINT)"  http://host:port/api/test/bigint/_stream_load
  • Note: In the import, because the original type is String, when the original data with floating point value is cast, the data will be converted to NULL, such as 12.0. Doris is currently not truncating raw data. *

If you want to force this type of raw data cast to int. Look at the following words:

curl --location-trusted -u root: -T ~/user_data/bigint -H "columns: tmp_k1, k1=cast(cast(tmp_k1 as DOUBLE) as BIGINT)"  http://host:port/api/test/bigint/_stream_load

mysql> select cast(cast ("11.2" as double) as bigint);
+----------------------------------------+
| CAST(CAST('11.2' AS DOUBLE) AS BIGINT) |
+----------------------------------------+
|                                     11 |
+----------------------------------------+
1 row in set (0.00 sec)

For the DECIMALV3 ,DATETIME type, the cast operation performs rounding half up.
mysql> select cast (1.115 as DECIMALV3(16, 2));
+---------------------------------+
| cast(1.115 as DECIMALV3(16, 2)) |
+---------------------------------+
|                            1.12 |
+---------------------------------+

mysql> select cast('2024-12-29-20:40:50.123500' as datetime(3));
+-----------------------------------------------------+
| cast('2024-12-29-20:40:50.123500' as DATETIMEV2(3)) |
+-----------------------------------------------------+
| 2024-12-29 20:40:50.124                             |
+-----------------------------------------------------+

mysql> select cast('2024-12-29-20:40:50.123499' as datetime(3));
+-----------------------------------------------------+
| cast('2024-12-29-20:40:50.123499' as DATETIMEV2(3)) |
+-----------------------------------------------------+
| 2024-12-29 20:40:50.123                             |
+-----------------------------------------------------+

keywords

CAST