CAST

description

Syntax

T cast (input as Type)

将 input 转成 指定的 Type类型

example

1. 转常量，或表中某列

1. mysql> select cast (1 as BIGINT);
2. +-------------------+
3. | CAST(1 AS BIGINT) |
4. +-------------------+
5. |                 1 |
6. +-------------------+

1. 转导入的原始数据

1. 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

注：在导入中，由于原始类型均为String，将值为浮点的原始数据做 cast的时候数据会被转换成 NULL ，比如 12.0 。Doris目前不会对原始数据做截断。

如果想强制将这种类型的原始数据 cast to int 的话。请看下面写法：

1. 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

3. mysql> select cast(cast ("11.2" as double) as bigint);
4. +----------------------------------------+
5. | CAST(CAST('11.2' AS DOUBLE) AS BIGINT) |
6. +----------------------------------------+
7. |                                     11 |
8. +----------------------------------------+
9. 1 row in set (0.00 sec)

对于DECIMALV3类型，cast会进行四舍五入

1. mysql> select cast (1.115 as DECIMALV3(16, 2));
2. +---------------------------------+
3. | cast(1.115 as DECIMALV3(16, 2)) |
4. +---------------------------------+
5. |                            1.12 |
6. +---------------------------------+

keywords

CAST