Host Variable Declaration
PP2 does not recognize every possible C variable declaration as valid for use in a SQL statement. For those types that have no direct C declaration, runtime processing allows the return of data to one of the other types.
Storage can be dynamically allocated for those data types not directly representable by a C declaration. This is useful when using dynamic SQLDA information returned by the Teradata Database.
The following table is a list of the equivalent C definitions for the Teradata Database data types.
|
Data Type |
Declaration |
Notes |
|
BYTE |
No direct equivalent |
1 |
|
VARBYTE |
No direct equivalent |
1 |
|
CHAR or CHAR (1) |
char identifier; |
|
|
CHAR (m) |
char identifier [m+1]; |
2 |
|
VARCHAR (m) |
VARCHAR identifier [m] |
3 |
|
TIME |
char identifier |
9 |
|
TIMESTAMP |
char identifier |
10 |
|
DATE |
long [int] identifier; |
4 |
|
DECIMAL (m, n) |
No direct equivalent |
5 |
|
NUMERIC (m, n) |
No direct equivalent |
5 |
|
FLOAT* |
float identifier; |
|
|
REAL* |
float identifier; |
|
|
DOUBLEPRECISION* |
float identifier; |
|
|
FLOAT** |
double identifier; |
|
|
REAL** |
double identifier; |
|
|
DOUBLE PRECISION** |
double identifier; |
|
|
BYTEINT |
No direct equivalent |
6 |
|
SMALLINT |
short [int] identifier; |
7 |
|
INTEGER |
long [int] identifier; |
8 |
|
*single precision **double precision |
||
Note:
|
1 )
|
Data can be returned to any valid host variable, although PP2 performs no data conversion.
|
|
2 )
|
The integer m must be positive, greater than one.
|
|
3 )
|
The integer m must be positive.
|
PP2 generates a structure with name identifier comprised of a short (2 bytes) len field and a character array field arr of length m.
No terminating null is expected or placed into the arr field.
|
4 )
|
The Teradata Database normally returns a DATE type field as integer.
|
It is possible to return the value in character string format, as long as the length of the receiving field is sufficient.
The DATEFORM=ANSIDATE format returns the DATE type field as CHAR (10).
|
5 )
|
Data can be returned to any valid numeric format, provided the value fits into the
field specified.
|
It is possible to allocate sufficient storage dynamically to hold the decimal field.
In this case, the application must provide for the data returned.
|
6 )
|
Data can be returned to any valid numeric format, provided the value fits into the
specified field.
|
It is possible to allocate sufficient storage dynamically to hold the byteint field.
In this case, the application must provide for the data returned.
|
7 )
|
PP2 allows specification of int identifier for a smallint on those systems where short and int are equivalent.
|
For a variable and statement it knows about, PP2 issues a warning about the size of the int field on a particular platform.
|
8 )
|
PP2 allows specification of int identifier for an integer on those systems where long and int are equivalent.
|
For a variable and statement it knows about, PP2 issues a warning about the size of the int field on a particular platform.
Note: The host variable defined as a long data type will be 4 bytes when compiled with the 32‑bit compiler option and 8 bytes when compiled with the 64‑bit compiler options on the Solaris, HP‑UX, AIX or 64‑bit Windows platforms.
When generating SQLDA for the static SQL statement, the PP2 precompiler assigns:
|
9 )
|
For TIME, the length of the char identifier should be 15.
|
|
10 )
|
For TIMESTAMP, the length of the char identifier should be 35.
|