|
   
Appendix
D . Data Types
D.1
ODBC SQL Data Types
D.2
ODBC C Data Types
D.3
Default ODBC C Data Types
D.4
Precision, Scale, Length, and Display Size
D.5
Data Type Conversions
D. Data Types
A driver
maps data source-specific SQL data types to ODBC SQL data types and
driver-specific SQL data types. Each SQL data type corresponds to an
ODBC C data type. The application can specify the correct C data type
with the fCType argument in SQLBindCol, SQLGetData,
or SQLBindParameter. Before sending data to the data source,
the driver converts it from the specified C data type. Before retrieving
data from the data source, the driver converts it to the specified C
data type.
In the
following sections, we will discuss :
ODBC SQL data types
ODBC C data types
Default ODBC C data types
Precision, scale, length and display size of SQL data types
Data type conversions
D.1 ODBC SQL Data Types
The table
on the following page lists the mapping between ODBC SQL data types
(the fSqlType column) and the corresponding DBMaker SQL data
types (SQL Data Type column). A description of the data types is also
listed in the table.
|
fSqlType
|
SQL
Data Type
|
Description
|
|
SQL_CHAR
|
CHAR(n)
|
Character
string of fixed length n (1 <= n <= 3992)
|
|
SQL_VARCHAR
|
VARCHAR(n)
|
Variable-length
character string with a maximum length n (1 <= n <= 3992)
|
|
SQL_LONGVARCHAR
|
LONG
VARCHAR
|
Variable
length character data with a maximum length of 2 GB
|
|
SQL_DECIMAL
|
DECIMAL(p,s)
(1)
DECIMAL(p)
DECIMAL
|
Signed
exact, numeric value with precision p and scale s (1<= p <=
17; 0 <= s <= p)
(6<=
p <= 17; s = 6)
(p
= 17; s = 6)
|
|
SQL_SMALLINT
|
SMALLINT
|
Exact
signed numeric value with precision 5 and scale 0 (32,768 <=
n <= 32,767)
|
|
SQL_INTEGER
|
INTEGER
|
Exact
signed numeric value with precision 10 and scale 0 (-231
<= n <= 231 -1)
|
|
SQL_REAL
(2)
|
FLOAT
|
Signed,
approximate, numeric value with a mantissa of precision 7 (10-38
to 1038)
|
|
SQL_FLOAT
|
DOUBLE
|
Signed,
approximate, numeric value with a mantissa of precision 15 (10^-308
to 10^308)
|
|
SQL_DOUBLE
|
DOUBLE
|
Signed,
approximate, numeric value with a mantissa of precision 15 (10^-308
to 10^308)
|
|
SQL_FILE
(3)
|
FILE
|
DBMaker
specific data type. Stores the data of a FILE column as
an external file.
|
|
SQL_BINARY
|
BINARY(n)
|
Binary
data of fixed length n (1 <= n <= 3992)
|
|
SQL_LONGVARBINARY
|
LONG
VARBINARY
|
Variable
length binary data with a maximum length of 2 GB
|
|
SQL_DATE
|
DATE
|
Date
data
|
|
SQL_TIME
|
TIME
|
Time
data
|
|
SQL_TIMESTAMP
|
TIMESTAMP
|
Includes
both date and time data
|
D.2 ODBC C Data Types
The ODBC
C data type is the data type used by an application to store data. The
C data type used is specified in the SQLBindCol, SQLGetData
and SQLBindParameter functions with the fCType argument.
The table on the following page lists the valid fCType values,
the ODBC C data type that implements each fCType value and the
corresponding C type both in PC and UNIX environments.
|
|
|
|
|
|
fcType
|
ODBC
C Typedef
|
C
Type
|
Bytes
|
|
SQL_C_CHAR
|
UCHAR
FAR *
|
unsigned
char FAR *
|
4
|
|
SQL_C_SSHORT
|
SWORD
|
short
int
|
2
|
|
SQL_C_SHORT
|
SWORD
|
short
int
|
2
|
|
SQL_C_USHORT
|
UWORD
|
unsigned
short int
|
2
|
|
SQL_C_SLONG
|
SDWORD
|
long
int
|
4
|
|
SQL_C_LONG
|
Same
as SQL_C_SLONG
|
|
|
|
SQL_C_ULONG
|
UDWORD
|
unsigned
long int
|
4
|
|
SQL_C_FLOAT
|
SFLOAT
|
float
|
4
|
|
SQL_C_DOUBLE
|
SDOUBLE
|
double
|
8
|
|
SQL_C_BINARY
|
UCHAR
FAR *
|
unsigned
char FAR *
|
4
|
|
SQL_C_DATE
|
DATE_STRUCT
|
struct
tagDATE_STRUCT
{
SWORD
year; (4)
UWORD month; (5)
UWORD
day; (6)
}
|
6
|
|
SQL_C_TIME
|
TIME_STRUCT
|
struct
tagTIME_STRUCT
{
UWORD
hour; (7)
UWORD
minutes; (8)
UWORD
second; (9)
}
|
6
|
|
SQL_C_TIMESTAMP
|
TIMESTAMP_STRUCT
|
struct
tagTIMESTAMP_STRUCT
{
SWORD
year; (4)
UWORD
month; (5)
UWORD
day; (6)
UWORD
hour; (7)
UWORD
minutes; (8)
UWORD
second; (9)
UDWORD
fraction; (10)
}
|
16
|
|
SQL_C_DEFAULT
|
see
the following section "Default C Data Types"
|
D.3 Default ODBC C Data Types
If an application
specifies SQL_C_DEFAULT for the fCType argument in SQLBindCol,
SQLGetData, or SQLBindParameter, the driver assumes that
the C data type of the output or input buffer corresponds to the SQL
data type of the column or parameter to which the buffer is bound. The
following table shows the default C data type for each ODBC SQL data
type.
|
SQL
Data Type
|
Default
C Data Type
|
|
SQL_CHAR
|
SQL_C_CHAR
|
|
SQL_VARCHAR
|
SQL_C_CHAR
|
|
SQL_LONGVARCHAR
|
SQL_C_CHAR
|
|
SQL_DECIMAL
|
SQL_C_CHAR
|
|
SQL_FILE
(11)
|
SQL_C_CHAR
|
|
SQL_SMALLINT
|
SQL_C_SSHORT
|
|
SQL_INTEGER
|
SQL_C_SLONG
|
|
SQL_REAL
|
SQL_C_FLOAT
|
|
SQL_FLOAT
|
SQL_C_FLOAT
|
|
SQL_DOUBLE
|
SQL_C_DOUBLE
|
|
SQL_BINARY
|
SQL_C_BINARY
|
|
SQL_LONGVARBINARY
|
SQL_C_BINARY
|
|
SQL_DATE
|
SQL_C_DATE
|
|
SQL_TIME
|
SQL_C_TIME
|
|
SQL_TIMESTAMP
|
SQL_C_TIMESTAMP
|
D.4 Precision, Scale, Length, and Display Size
SQLColAttributes,
SQLColumns, and SQLDescribeCol return the precision, scale,
length, and display size of a column in a table. SQLDescribeParam
returns the precision or scale of a parameter in an SQL statement. SQLBindParameter
sets the precision or scale of a parameter in an SQL statement. SQLGetTypeInfo
returns the maximum precision and the minimum and maximum scales of
an SQL data type on a data source. The following table lists the precision,
scale, length and display size for each ODBC SQL type. A `-` means the
value has no meaning or the corresponding type cannot be determined.
For example, scale is not applicable for dates, and the precision of
SQL_LONGVARCHAR can not be determined as it only refers to how many
bytes of data are stored.
|
fSqlType
|
SQL
Data Type
|
Precision
(12)
|
Scale
(13)
|
Length
|
Display
Size
|
|
SQL_CHAR
|
CHAR(n)
|
n
|
-
|
n
|
n
|
|
SQL_VARCHAR
|
VARCHAR(n)
|
n
|
-
|
n
|
n
|
|
SQL_LONGVARCHAR
|
LONG
VARCHAR
|
-
|
-
|
-
|
-
|
|
SQL_DECIMAL
(14)
|
DECIMAL(p,s)
|
p
|
s
|
(p+3)/2
|
p+2
|
|
SQL_FILE3
|
FILE
|
79
|
-
|
79
|
-
|
|
SQL_SMALLINT
|
SMALLINT
|
5
|
0
|
2
|
6
|
|
SQL_INTEGER
|
INTEGER
|
10
|
0
|
4
|
11
|
|
SQL_REAL
|
FLOAT
|
7
|
-
|
4
|
13
|
|
SQL_FLOAT
|
FLOAT
|
7
|
-
|
4
|
13
|
|
SQL_DOUBLE
|
DOUBLE
|
15
|
-
|
8
|
22
|
|
SQL_BINARY
|
BINARY(n)
|
n
|
-
|
n
|
2n
|
|
SQL_LONGVARBINARY
|
LONG
VARBINARY
|
-
|
-
|
-
|
-
|
|
SQL_DATE
|
DATE
|
11
|
-
|
6
|
11
|
|
SQL_TIME
|
TIME
|
15
|
3
|
6
|
15
|
|
SQL_TIMESTAMP
|
TIMESTAMP
|
27
|
3
|
16
|
27
|
D.5 Data Type Conversions
Two sections
are used to explain data type conversions: one is for SQL to C data
conversions, the other is for C to SQL data conversions. In each section,
we also illustrate the examples to show the results of specified data
type conversions.
SQL to C Data Conversion
Before
retrieving data with SQLFetch, you should specify the data type
to which the retrieved data is converted in the argument fCType
of SQLBindCol. Finally, the driver will store the data in the
location pointed to by the rgbValue argument in SQLBindCol.
SQLGetData has the similar situation. The table on the following
page lists the data type conversions, from SQL to C data type, which
are provided by DBMaker.
The table
on the following page shows the examples which illustrate how DBMaker
converts SQL data to C data. Differences from the ODBC standard are
listed in the footnotes at the bottom of the page.
|
|
|
|
|
|
|
SQL
Data Type
|
SQL
Data Value
|
C
Data Type
|
C
Len
|
C
Data Value
|
sqlstate
|
|
SQL_CHAR
|
abcdef
|
SQL_C_CHAR
|
7
|
abcdef\0
|
N/A
|
|
SQL_CHAR
|
abcdef
|
SQL_C_CHAR
|
6
|
abcde\0
|
01004
|
|
SQL_CHAR
|
abcdef
|
SQL_C_BINARY
|
6
|
abcdef
|
N/A
|
|
SQL_CHAR
|
abcdef
|
SQL_C_BINARY
|
5
|
abcde
|
01004
|
|
SQL_VARCHAR
|
same
as SQL_CHAR
|
|
SQL_LONGVARCHAR
|
same
as SQL_CHAR
|
|
SQL_DECIMAL
|
1234.56
|
SQL_C_CHAR
|
8
|
1234.56\0
|
N/A
|
|
SQL_DECIMAL
|
1234.56
|
SQL_C_CHAR
|
5
|
1234\0
|
01004
|
|
SQL_DECIMAL
|
1234.56
|
SQL_C_CHAR
|
4
|
-
|
22003
|
|
SQL_DECIMAL
|
1234.56
|
SQL_C_FLOAT
|
-
|
1234.56
|
N/A
|
|
SQL_DECIMAL
|
1234.56
|
SQL_C_SHORT
|
-
|
1234
|
01004
|
|
SQL_SMALLINT
|
7890
|
SQL_C_CHAR
|
5
|
7890\0
|
N/A
|
|
SQL_SMALLINT
|
7890
|
SQL_C_CHAR
|
4
|
-
|
22003
|
|
SQL_SMALLINT
|
7890
|
SQL_C_LONG
|
-
|
7890
|
N/A
|
|
SQL_INTEGER
|
65000
|
SQL_C_LONG
|
-
|
65000
|
N/A
|
|
SQL_INTEGER
|
65000
|
SQL_C_SSHORT
|
-
|
-
|
22003
|
|
SQL_DOUBLE
|
1.2345678
|
SQL_C_DOUBLE
|
-
|
1.2345678
|
N/A
|
|
SQL_DOUBLE
|
1.2345678
|
SQL_C_FLOAT
|
-
|
1.234567
|
N/A
|
|
SQL_DOUBLE
|
1.2345678
|
SQL_C_SHORT
|
-
|
1
|
01004
|
|
SQL_FLOAT
|
same
as SQL_DOUBLE
|
|
SQL_REAL
|
same
as SQL_DOUBLE
|
|
SQL_DATE
|
1995-11-29
|
SQL_C_CHAR
|
11
|
1995-11-29\0
|
N/A
|
|
SQL_DATE
|
1995-11-29
|
SQL_C_CHAR
|
10
|
-
|
22003
(15)
|
|
SQL_DATE
|
1995-11-29
|
SQL_C_CHAR
|
10
|
11-29-95\0
|
N/A
(16)
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
19
|
22:11:33.320\0
|
N/A
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
12
|
22:11:33.32\0
|
01004
(17)
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
11
|
22:11:33.3\0
|
010043
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
10
|
22:11:33\0
|
010041
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
9
|
22:11:33\0
|
010043
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
8
|
-
|
22003
(18)
|
|
SQL_TIME
|
22:11:33.32
|
SQL_C_CHAR
|
|
10
PM\0
|
N/A
(19)
|
|
SQL_TIMESTAMP
|
1995-11-29
23:54:38.234
|
SQL_C_CHAR
|
24
|
1995-11-29
23:54:38.234\0
|
N/A
|
|
SQL_TIMESTAMP
|
1995-11-29
23:54:38.234
|
SQL_C_CHAR
|
22
|
1995-11-29
23:54:38.2\0
|
01004
(20)
|
|
SQL_TIMESTAMP
|
1995-11-29
23:54:38.234
|
SQL_C_CHAR
|
19
|
-
|
22003
(21)
|
|
SQL_TIMESTAMP
|
1995-11-29
23:54:38.234
|
SQL_C_CHAR
|
19
|
11/29/95
23:54:38\0
|
N/A
(22)
|
|
SQL_BINARY
|
ABCDEFG
|
SQL_C_CHAR
|
15
|
65666768696A6B\0
|
N/A
|
|
SQL_BINARY
|
ABCDEFG
|
SQL_C_CHAR
|
14
|
65666768696A6\0
|
01004
|
|
SQL_BINARY
|
ABCDEFG
|
SQL_C_BINARY
|
7
|
ABCDEFG
|
N/A
|
|
SQL_BINARY
|
ABCDEFG
|
SQL_C_BINARY
|
6
|
ABCDEF
|
01004
|
|
SQL_LONGVARBINARY
|
same
as SQL_BINARY
|
|
SQL_FILE
|
abcdefg
|
SQL_C_CHAR
|
8
|
abcdefg\0
|
N/A
(23)
|
|
SQL_FILE
|
abcdefg
|
SQL_C_FILE
|
8
|
student\0
|
N/A
(24)
|
C to SQL Data Conversion
When an
application calls SQLExecute or SQLExecDirect, the driver
retrieves the data for any parameters bound with SQLBindParameter
from storage locations in the application. If necessary, before the
driver sends the data to the data source, it converts the data from
the data type specified by the fCType argument in SQLBindParameter
to the data type specified by the fSqlType argument in SQLBindParameter.
For data-at-execution parameters, the application sends the parameter
with SQLPutData. The following table show the supported conversions
from ODBC C data types to ODBC SQL data types by DBMaker. Any differences
between DBMaker and the ODBC 3.0 specification are shown at the bottom
of the page.
Note:
The behavior of the SQL_C_LONG data type is the same as the SQL_C_SLONG
data type.
The following
table shows the examples which illustrate how DBMaker converts C data
to SQL data Any differences between DBMaker and the ODBC 3.0 specification
are shown at the bottom of the page.
|
|
|
|
|
|
|
C
Data Type
|
C
Data Value
|
SQL
Data Type
|
Col
Len
|
SQL
Data
|
sqlstate
|
|
SQL_C_CHAR
|
abcdef\0
|
SQL_CHAR
|
6
|
abcdef
|
N/A
|
|
SQL_C_CHAR
|
abcdef\0
|
SQL_CHAR
|
5
|
abcde
|
01004
|
|
SQL_C_CHAR
|
1234.56\0
|
SQL_DECIMAL
|
6,2
|
1234.56
|
N/A
|
|
SQL_C_CHAR
|
1234.56\0
|
SQL_DECIMAL
|
5,1
|
1234.5
|
01004
|
|
SQL_C_CHAR
|
1234.56\0
|
SQL_DECIMAL
|
6,3
|
-
|
N/A
|
|
SQL_C_CHAR
|
1234\0
|
SQL_INTEGER
|
-
|
1234
|
N/A
|
|
SQL_C_CHAR
|
1234.56\0
|
SQL_INTEGER
|
-
|
1234
|
01004
|
|
SQL_C_CHAR
|
12345678912\0
|
SQL_INTEGER
|
-
|
-
|
22003
|
|
SQL_C_CHAR
|
abcdef\0
|
SQL_INTEGER
|
-
|
-
|
22005
|
|
SQL_C_CHAR
|
abcdef\0
|
SQL_SMALLINT
|
-
|
-
|
22005
|
|
SQL_C_CHAR
|
1234.56\0
|
SQL_FLOAT
|
-
|
1234.56
|
N/A
|
|
SQL_C_CHAR
|
1234.5678\0
|
SQL_FLOAT
|
-
|
1234.5678
|
N/A
|
|
SQL_C_CHAR
|
1.23456e+4\0
|
SQL_FLOAT
|
-
|
1234.56
|
N/A
|
|
SQL_C_CHAR
|
abcdef\0
|
SQL_FLOAT
|
-
|
-
|
22005
|
|
SQL_C_CHAR
|
|
SQL_DOUBLE
|
same as SQL_FLOAT
|
|
SQL_C_CHAR
|
666768696A6b\0
|
SQL_BINARY
|
6
|
BCDEFG
|
N/A
|
|
SQL_C_CHAR
|
666768696A6\0
|
SQL_BINARY
|
6
|
BCDEF
|
N/A
|
|
SQL_C_CHAR
|
666768696A6b\0
|
SQL_BINARY
|
5
|
BCDEF
|
01004
|
|
SQL_C_CHAR
|
HHKKLLMM\0
|
SQL_BINARY
|
6
|
-
|
22005
|
|
SQL_C_CHAR
|
1995-11-29\0
|
SQL_DATE
|
-
|
1995-11-29
|
N/A
|
|
SQL_C_CHAR
|
1995-11-29
00:00:00.00\0
|
SQL_DATE
|
-
|
1995-11-29
|
N/A
|
|
SQL_C_CHAR
|
1995-11-29
23:54:38.23\0
|
SQL_DATE
|
-
|
1995-11-29
|
01004
|
|
SQL_C_CHAR
|
1995/22/33
|
SQL_DATE
|
-
|
-
|
22008
|
|
SQL_C_CHAR
|
17:18:19.123
|
SQL_TIME
|
-
|
17:18:19.123
|
N/A
(25)
|
|
SQL_C_CHAR
|
1995-11-29
17:18:19.123
|
SQL_TIMESTAMP
|
-
|
1995-11-29
17:18:19.123
|
N/A
|
|
SQL_C_CHAR
|
homework\0
|
SQL_FILE
|
9
|
abcdefg
|
N/A
(26)
|
|
SQL_C_SHORT
|
7890
|
SQL_SMALLINT
|
-
|
7890
|
N/A
|
|
SQL_C_SSHORT
|
7890
|
SQL_VARCHAR
|
-
|
-
|
S1C00
|
|
SQL_C_SSHORT
|
7890
|
SQL_BINARY
|
-
|
-
|
07006
|
|
SQL_C_SSHORT
|
7890
|
SQL_SMALLINT
|
-
|
7890
|
N/A
(27)
|
|
SQL_C_SSHORT
|
7890
|
SQL_INTEGER
|
-
|
7890
|
N/A
|
|
SQL_C_USHORT
|
7890
|
SQL_INTEGER
|
-
|
7890
|
N/A
|
|
SQL_C_LONG
|
7890
|
SQL_INTEGER
|
-
|
7890
|
N/A
|
|
SQL_C_SLONG
|
7890
|
SQL_INTEGER
|
-
|
7890
|
N/A
|
|
SQL_C_ULONG
|
7890
|
SQL_INTEGER
|
-
|
7890
|
N/A
|
|
SQL_C_FLOAT
|
1234.00
|
SQL_INTEGER
|
-
|
1234
|
N/A
|
|
SQL_C_FLOAT
|
1234.56
|
SQL_INTEGER
|
-
|
1234
|
01004
|
|
SQL_C_FLOAT
|
1234567.24
|
SQL_SMALLINT
|
-
|
-
|
22003
|
|
SQL_C_FLOAT
|
1234.56
|
SQL_DECIMAL
|
6,2
|
1234.56
|
N/A
|
|
SQL_C_FLOAT
|
1234.56
|
SQL_DECIMAL
|
5,1
|
1234.5
|
01004
|
|
SQL_C_FLOAT
|
1234.56
|
SQL_DECIMAL
|
6,3
|
-
|
22003
|
|
SQL_C_DOUBLE
|
same
as SQL_C_FLOAT
|
|
|
|
|
|
SQL_C_BINARY
|
ABCDEF
|
SQL_BINARY
|
6
|
ABCDEF
|
N/A
|
|
SQL_C_BINARY
|
ABCDEF
|
SQL_BINARY
|
5
|
ABCDE
|
01004
|
|
SQL_C_DATE
|
1996,3,8
|
SQL_DATE
|
-
|
1996,3,8
|
N/A
|
|
SQL_C_DATE
|
1996,3,8
|
SQL_TIME
|
-
|
-
|
07006
(28)
|
|
SQL_C_DATE
|
1996,3,8
|
SQL_TIMESTAMP
|
-
|
1996,3,8,
0,0,0,0
|
N/A
(29)
|
|
SQL_C_TIME
|
13,14,15
|
SQL_DATE
|
-
|
-
|
07006
(30)
|
|
SQL_C_TIME
|
13,14,15
|
SQL_TIME
|
-
|
13,14,15
|
N/A
|
|
SQL_C_TIME
|
13,14,15
|
SQL_TIMESTAMP
|
-
|
1996,3,8,
13,14,15
|
N/A
(31)
|
|
SQL_C_TIMESTAMP
|
1996,3,8,
13,14,15, 160000000
|
SQL_DATE
|
-
|
1996,3,8
|
01004
(32)
|
|
SQL_C_TIMESTAMP
|
1996,3,8,
13,14,15, 160000000
|
SQL_TIME
|
-
|
13,14,15
|
01004
(33)
|
|
SQL_C_TIMESTAMP
|
1996,3,8,
13,14,15, 160000000
|
SQL_TIMESTAMP
|
-
|
1996,3,8,
13,14,15, 160000000
|
N/A
|
|
SQL_C_TIMESTAMP
|
1996,3,8,
13,14,15, 167800000
|
SQL_TIMESTAMP
|
-
|
1996,3,8,
13,14,15, 167000000
|
01004
(34)
|
|
SQL_C_FILE
|
homework\0
|
SQL_LONGVARCHAR
|
6
|
abcdefg
|
N/A
(35)
|
Footnotes
1 p (precision) is the total number of digits and s (scale) is the number
of digits right of the decimal point.
2 Slight differences exist between the DBMaker and ODBC 2.0 definition
of this data type.
3 An extended data type supported by DBMaker and not included in ODBC
2.0.
4 Valid year values are in the range 1 to 9999.
5 Valid month values are in the range 1 to 12.
6 Valid day values are in the range 1 to the number of days in the month.
7 Valid hour values are in the range 0 to 23.
8 Valid minute values are in the range 0 to 59.
9 Valid second values are in the range 0 to 59.
10 Valid fraction values are in the range 0 to 999,999,999. For example,
500,000,000 represents a half-second. 1,000,000 is a thousandth of a
second. 1,000 is a millionth of a second (a microsecond). 1 is a billionth
of a second (a nanosecond).
11 Slight differences exist between the DBMaker and ODBC 2.0 definition
of this data type.
12 The precision of date, time and timestamp are all defined as the
same as their lagrest display size, which are the maximum length of
date, time and timestamp format corespondently (dd/mon/yyyy, hh:mm:ss.nnn
tt, dd/mon/yyyy hh:mm:ss.nnn tt)
13 The scale of time and timestamp are 3. It means the number of digits
in fractional part which could be precisely accepted by DBMaker.
14 Slight differences exist between the DBMaker and ODBC 2.0 definition
of this data type.
15 the output data and returned code are according to the date output
format set by the user. If the output format for date is yyyy-mm-dd,
then the size of user buffer must be at least 11 bytes, otherwise ERROR
will be returned.
16 the output data and returned code are according to the date output
format set by the user. If the output format for the date is mm-dd-yy,
then the size of the user buffer must be at least 9 bytes, otherwise
ERROR will be returned.
17 The output data and returned code are according to the time output
format setted by user. If the time output format specifies the fractional
part, ex: hh:mm:ss.fff, and user buffer is not large enough for put
the fractional digits, then wanring message of data truncated will be
returned.
18 If the time output format contains second field, ex: hh:mm:ss, but
the user buffer is not large enough to carry the second value, ERROR
will be returned.
19 suppose user specify the time output format as hh tt, even though
minute and second data is lost, no error will be returned because user
only want the information for hour.
20 same reason as 1
21 same reason as 2
22 The rule for timestamp format combines both the date format rulls
and time format rulls above. So, if the date output format is mm/dd/yy
and time output format is hh:mm:ss, then the buffer size must be at
least 18 (8 + 1 + 8 + 1), otherwise error will be returned.
23 suppose a column type is FILE, use SQL_C_CHAR to bind this column
will fetch the contents of this file into the user buffer, ex: abcdefg
is the contents of a file called 'homework', then abcdefg will be putted
to the user buffer.
24 the same example as 7, but use SQL_C_FILE to bind this column will
fetch the file contents into the new file (ex: student) which is specified
by the user buffer.
25 according to the date input format
26 If there is one file of the server site named 'homework' then use
SQL_C_CHAR to bind parameter will let the specified FILE column link
to the file 'homework'.
27 SQL_C_SSHORT, SQL_C_SHORT, SQL_C_SLONG, SQL_C_LONG, SQL_C_FLOAT and
SQL_C_DOUBLE are numeric ODBC C data types
28 SQL_C_DATE cannot be converted to SQL_TIME.
29 When converting SQL_C_DATE to SQL_TIMESTAMP, the time portion of
the timestamp is set to zero.
30 SQL_C_TIME cannot be converted to SQL_DATE.
31 The date part of timestamp will be set to the current date when converting
SQL_TIME to SQL_C_TIMESTAMP.
32 If the time portion is not zero, data truncated warning will be returned
when converting SQL_C_TIMESTAMP to SQL_DATE
33 If the fractional part is not zero, data truncated warning will be
returned when converting SQL_C_TIMESTAMP to SQL_TIME
34 Because only 3 digits after decimial in the fractional portion of
the timestamp are assured, warning message will be returned when more
than 3 digits after decimal.
35 If there is one file called 'homework' on the client site, and its
contents are abcdefg, then use SQL_C_FILE to bind parameter will insert
its contents into the BLOB or FILE column.
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