OceanBase CAST

expr

列名或者表達(dá)式。

AS

用于分隔兩個(gè)參數(shù)，在 AS 之前的是要處理的數(shù)據(jù)，在 AS 之后是要轉(zhuǎn)換的數(shù)據(jù)類型。

type_name

數(shù)據(jù)類型為 OceanBase 的 內(nèi)建數(shù)據(jù)類型。

from BINARY_FLOAT, BINARY_DOUBLE

from CHAR, VARCHAR2

from NUMBER

from DATETIME/INTERVAL

from RAW

from NCHAR, NVARCHAR2

to BINARY_FLOAT, BINARY_DOUBLE

yes

yes

yes

no

no

yes

to CHAR, VARCHAR2

yes

yes

yes

yes

yes

no

to NUMBER

yes

yes

yes

no

no

yes

to DATETIME, INTERVAL

no

yes

no

yes

no

no

to RAW

yes

yes

yes

no

yes

no

to NCHAR, NVARCHAR2

yes

no

yes

yes

yes

yes