SQL/MX Programming Manual for C and COBOL (G06.24+, H06.03+)

Host Variables in C/C++ Programs
HP NonStop SQL/MX Programming Manual for C and COBOL—523627-004
3-11
Data Conversion
Data Conversion
NonStop SQL/MX performs the conversion between SQL and C data types:
•
When a host variable serves as an input variable (supplies a value to the
database), NonStop SQL/MX converts the value that the variable contains to a
compatible SQL data type and then uses the value in the SQL operation.
•
When a host variable serves as an output variable (receives a value from a
database), NonStop SQL/MX converts the value to the data type of the host
variable.
NonStop SQL/MX supports conversion within numeric types and character types—but
not between numeric and character types.
Converting Numeric Types
Values of data types NUMERIC, DECIMAL, PICTURE 9’s, INTEGER, SMALLINT,
FLOAT, REAL, and DOUBLE PRECISION are numbers and are all mutually
comparable and mutually assignable.
VARCHAR(99)CHARACTER
SET KANJI
**
VARCHAR CHARACTER SET
IS KANJI a[100]
VARCHAR CHARACTER SET
IS KANJI a[100
CHARACTERS]
wchar_t a[100]
VARCHAR(99)CHARACTER
SET KSC5601
**
VARCHAR CHARACTER SET
IS KSC5601 a[100]
VARCHAR CHARACTER SET
IS KSC5601 a[100
CHARACTERS]
wchar_t a[100]
CHAR(99)CHARACTER SET X NCHAR a[100
CHARACTERS]
Depends on X (X is the
value of the system
default
NATIONAL_CHARSET)
VARCHAR(99)CHARACTER
SET X
NCHAR VARYING a[100
CHARACTERS]
Depends on X
(X is the
value of the system
default
NATIONAL_CHARSET)
Table 3-4. Corresponding SQL, C Host Variable Data Types, and Translated C
Declarations (page 2 of 2)
SQL Data Type C Host Variable Data Type
Translated C
Declaration
* An extra character is generated as a placeholder for a null terminator. The embedded SQL C VARCHAR
data type is SQL:1999.
** KANJI and KSC5601 character sets can be used only with SQL/MP tables.