Supported SQL data types in C and C++ routines

Lists the supported mappings between SQL data types and C data types for routines.

Accompanying each C/C++ data type is the corresponding defined type from sqludf.h.

Table 1. SQL Data Types Mapped to C/C++ Declarations
SQL Column Type C/C++ Data Type SQL Column Type Description
SMALLINT sqlint16
SQLUDF_SMALLINT		 16-bit signed integer
INTEGER sqlint32
SQLUDF_INTEGER		 32-bit signed integer
BIGINT sqlint64
SQLUDF_BIGINT		 64-bit signed integer
REAL
FLOAT(n) where 1<=n<=24		 float
SQLUDF_REAL		 Single-precision floating point
DOUBLE
FLOAT
FLOAT(n) where 25<=n<=53		 double
SQLUDF_DOUBLE		 Double-precision floating point
DECIMAL(p, s) Not supported. To pass a decimal value, define the parameter to be of a data type castable from DECIMAL (for example CHAR or DOUBLE) and explicitly cast the argument to this type.
CHAR(n) char[n+1] where n is large enough to hold the data
1<=n<=255

SQLUDF_CHAR
 Fixed-length, null-terminated character string
CHAR(n) FOR BIT DATA char[n] where n is large enough to hold the data
1<=n<=255

SQLUDF_CHAR
 Fixed-length, not null-terminated character string
VARCHAR(n) char[n+1] where n is large enough to hold the data
1<=n<=32 672

SQLUDF_VARCHAR
 Null-terminated varying length string
VARCHAR(n) FOR BIT DATA
struct {
sqluint16 length;
char[n]
}

1<=n<=32 672

SQLUDF_VARCHAR_FBD
 Not null-terminated varying length character string
LONG VARCHAR
struct {
sqluint16 length;
char[n]
}

1<=n<=32 700

SQLUDF_LONG
 Not null-terminated varying length character string
CLOB(n)
struct {
sqluint32 length;
char      data[n];
}

1<=n<=2 147 483 647

SQLUDF_CLOB
 Not null-terminated varying length character string with 4-byte string length indicator
BINARY char[n] where n is large enough to hold the data
1<=n<=255

SQLUDF_BINARY
 Fixed-length, not null-terminated binary string
VARBINARY
struct {
sqluint16 length;
char[n]
}

1<=n<=32 672

SQLUDF_VARBINARY
 Not null-terminated varying length binary string
BLOB(n)
struct {
sqluint32 length;
char      data[n];
}

1<=n<=2 147 483 647

SQLUDF_BLOB
 Not null-terminated varying binary string with 4-byte string length indicator
DATE
char[11]
SQLUDF_DATE
 Null-terminated character string of the following format: 
yyyy-mm-dd
TIME
char[9]
SQLUDF_TIME
 Null-terminated character string of the following format: 
hh.mm.ss
TIMESTAMP
char[20] - char[33]
SQLUDF_STAMP
 Null-terminated character string of the following format: 
yyyy-mm-dd-hh.mm.ss.nnnnnnnnnnnn

The character string can be from 19 - 32 bytes in length depending on the number of fractional seconds specified. The fractional seconds of the TIMESTAMP data type can be optionally specified with 0-12 digits of timestamp precision.

For example: 
(VALUES(CURRENT TIMESTAMP(0))
1               
-------------------
2008-07-09-14.48.36

  1 record(s) selected.

LENGTH (VALUES(CURRENT TIMESTAMP(0))
1               
-------------------
19

  1 record(s) selected.
(VALUES(CURRENT TIMESTAMP(12))
1               
-------------------
2008-07-09-14.48.36.123456789012

  1 record(s) selected.

LENGTH (VALUES(CURRENT TIMESTAMP(0))
1               
-------------------
32

When a timestamp value is assigned to a timestamp variable with a different number of fractional seconds, the value is either truncated or padded with 0's to match the format of the timestamp variable.
LOB LOCATOR
sqluint32
SQLUDF_LOCATOR
 32-bit signed integer
GRAPHIC(n) sqldbchar[n+1] where n is large enough to hold the data
1<=n<=127

SQLUDF_GRAPH
 Fixed-length, null-terminated double-byte character string
VARGRAPHIC(n) sqldbchar[n+1] where n is large enough to hold the data
1<=n<=16 336

SQLUDF_GRAPH
 Null-terminated, variable-length double-byte character string
LONG VARGRAPHIC
struct {
sqluint16 length;
sqldbchar[n]
}

1<=n<=16 350

SQLUDF_LONGVARG
 Not null-terminated, variable-length double-byte character string
DBCLOB(n)
struct {
sqluint32  length;
sqldbchar data[n];
}

1<=n<=1 073 741 823

SQLUDF_DBCLOB
 Not null-terminated varying length character string with 4-byte string length indicator
XML AS CLOB
struct {
sqluint32 length;
char      data[n];
}

1<=n<=2 147 483 647

SQLUDF_CLOB
 Not null-terminated varying length serialized character string with 4-byte string length indicator.
Note: XML data types can only be implemented as CLOB data types in external routines implemented in C or C++.
Note: The following data types are only available in the DBCS or EUC environment when precompiled with the WCHARTYPE NOCONVERT option:
  • GRAPHIC(n)
  • VARGRAPHIC(n)
  • LONG VARGRAPHIC
  • DBCLOB(n)