Data Type Conversion

Certain data types in the database support implicit data type conversions, such as assignments and parameters called by functions. For other data types, you can use the type conversion functions provided by openGauss, such as the CAST function, to forcibly convert them.

openGauss lists common implicit data type conversions in Table 1.

NOTICE:
The valid value range of DATE supported by openGauss is from 4713 B.C. to 294276 A.D.

Table 1 Implicit data type conversions

Raw Data Type	Target Data Type	Remarks
CHAR	VARCHAR2	-
CHAR	NUMBER	Raw data must consist of digits.
CHAR	DATE	Raw data cannot exceed the valid date range.
CHAR	RAW	-
CHAR	CLOB	-
VARCHAR2	CHAR	-
VARCHAR2	NUMBER	Raw data must consist of digits.
VARCHAR2	DATE	Raw data cannot exceed the valid date range.
VARCHAR2	CLOB	-
NUMBER	CHAR	-
NUMBER	VARCHAR2	-
DATE	CHAR	-
DATE	VARCHAR2	-
RAW	CHAR	-
RAW	VARCHAR2	-
CLOB	CHAR	-
CLOB	VARCHAR2	-
CLOB	NUMBER	Raw data must consist of digits.
INT4	CHAR	-
INT4	BOOLEAN	-
BOOLEAN	INT4	-