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Sybase dbQueue Reference Guide

Chapter 1: Using the dbQueue Objects Library

Datatypes

Datatypes

The dbQueue objects library defines standard primitive datatypes used by library methods. These datatypes are defined in the DbqCommon.h header file, which also includes enumerated types and other definitions used throughout the library.

dbQueue datatypes fall into two categories:

• C++ only datatypes used in the dbQueue objects library that are not represented directly in the messages. Method return codes are an example of such a datatype.
• Datatypes used that map to the types used for message columns. Some of these datatypes, such as strings, are also used in other dbQueue objects library calls.

The precise mapping of types into C++ types may vary by platform. Check the DbqCommon.h header file for the final mapping assignments.

C++ Only Datatypes

C++ datatypes include return codes and Boolean values.

Return Codes

dbQueue objects library methods that generate errors always return a DBQ_STATUS value. DBQ_STATUS values always equate to integer constants that fall into one of the following categories:

• DBQ_SUCCEED - Method completed successfully.
• Error codes - Defined for each method.

Boolean Values

The dbQueue objects library provides DBQ_BOOLEAN to represent TRUE and FALSE values. The following code sample shows how boolean values can be used:

if (env->GetAutoImplement() != DBQ_TRUE) 

    env->SetAutoImplement(DBQ_TRUE); 

The dbQueue implementation ensures that DBQ_FALSE and DBQ_TRUE equate to FALSE and TRUE respectively when they are used in C++ Boolean expressions. For example, applications can also be programmed as the following:

if (! env->GetAutoImplement())

    env->SetAutoImplement(DBQ_TRUE); 

Message Datatypes

These datatypes defined by dbQueue objects are typedefs of the C++ representation of the identically named dbQueue message datatypes. dbQueue datatypes generally map to ODBC datatypes.

Table 1-1 shows dbQueue datatypes mapping into C++ representations and ODBC datatype definitions.

Table 1-1: dbQueue datatype mapping to C++ and ODBC

dbQueue datatype Name	C++ Representation	ODBC Type Name
DBQ_BINARY	unsigned char*	SQL_C_BINARY
DBQ_BIT	unsigned char	SQL_C_BIT
DBQ_CHAR	unsigned char*	SQL_C_CHAR
DBQ_DATETIME	TIME_STAMP_STRUCT	SQL_C_TIMESTAMP
DBQ_DECIMAL	unsigned char*	SQL_C_DECIMAL
DBQ_FLOAT	double	SQL_C_DOUBLE
DBQ_IMAGE	unsigned char*	SQL_C_BINARY
DBQ_INTEGER	int	SQL_C_DOUBLE
DBQ_MONEY	unsigned char*	SQL_C_CHAR
DBQ_NUMERIC	unsigned char*	SQL_C_CHAR
DBQ_REAL	float	SQL_C_FLOAT
DBQ_SMALLDATETIME	TIMESTAMP_STRUCT	SQL_C_TIMESTAMP
DBQ_SMALLINT	short int	SQL_C_SSHORT
DBQ_SMALLMONEY	unsigned char*	SQL_C_CHAR
DBQ_TEXT	unsigned char*	SQL_C_CHAR
DBQ_TINYINT	signed char	SQL_C_STINYINT
DBQ_VARBINARY	unsigned char*	SQL_C_CHAR
DBQ_VARCHAR	unsigned char*	SQL_C_CHAR

For a full description of SQL datatypes and their values, see Appendix A, "Datatypes."