functions

The functions begin with the mi_ prefix. The milib.h header file declares most of these functions.

The mi.h header file automatically includes milib.h. You must include mi.h in any module that uses a function.

The functions of the function library can be divided into the categories shown in the following table.

Table 1. Categories of functions
This table lists categories of functions with links to topics that contain more information. The table is divided into parts. The first part lists data handling categories. The next part of the table lists session, thread, and transaction management categories. The remaining parts of the table list SQL statement processing categories, categories for executing user-defined routines, memory management categories, exception handling categories, smart-large object interface categories, an operating system file category, and a tracing category.
Category of functions	More information
Data handling:
Obtaining type information	Type identifiers Type descriptors
Transferring data types between computers (database server only)	Conversion of opaque-type data with computer-specific data types
Converting data to a different data type	functions for date conversion functions for date-time or interval conversion functions for decimal conversion functions for string conversion
Handling collections: sets, multisets, and lists	Collections
Converting between code sets (database server only)	Internationalization of modules (GLS)
Handling collections	Collections
Managing varying-length structures	Varying-length data type structures
Obtaining SERIAL values	Process insert results
Handling NULL values	SQL NULL value
Session, thread, and transaction management:
Obtaining connection information	Connection parameters Database parameters Session parameters
Establishing a connection	Establish a connection
Initializing the	Initialize the
Managing HCL Informix® threads (database server only)	Yield the CPU VP Manage stack usage
Obtaining transaction and server-processing state changes	A transition descriptor
SQL statement processing:
Sending SQL statements	Execute basic SQL statements Execute prepared SQL statements
Obtaining statement information	Return a statement descriptor Obtain input-parameter information
Obtaining result information	Process statement results
Retrieving rows and row data (also row types and row-type data)	Obtain row information Retrieve rows
Retrieving columns	Obtain column information Obtain column values
Using save sets	Save sets
Executing user-defined-routines:
Accessing an MI_FPARAM structure	Access MI_FPARAM routine-state information
Allocating an MI_FPARAM structure	A user-allocated MI_FPARAM structure
Using the Fastpath interface	Call UDRs with the Fastpath interface
Accessing a function descriptor	Obtain information from a function descriptor
Executing selectivity and cost functions:	Write selectivity and cost functions
Memory management:
Managing user memory	Manage user memory
Managing named memory (database server only)	Manage named memory
Exception handling:
Raising a database exception	Raise an exception
Accessing an error descriptor	An error descriptor, Handling multiple exceptions
Using callback functions	Invoke a callback
Smart-large-object interface:
Creating a smart large object	Functions that create a smart large object
Performing I/O on a smart large object	Functions that perform input and output on a smart large object
Moving smart large objects to and from operating-system files	Functions that move smart large objects to and from operating-system files
Manipulating LO handles	Functions that manipulate an LO handle
Handling LO-specification structures	Functions that access an LO-specification structure
Handling smart-large-object status	Functions that access an LO-status structure
Operating-system file interface:	Access to operating-system files
Tracing (database server):	Tracing

For a complete list of functions in each of these categories, see the IBM® Informix® DataBlade® API Function Reference, which provides descriptions of the regular public and advanced functions, in alphabetical order. For more information about advanced functions of the , see Advanced features (Server).

If an error occurs while a function executes, the function usually indicates the error with one of the following return values.


Way to indicate an error	More information
Functions that return a pointer return the NULL-valued pointer	NULL-valued pointer
Functions that return an mi_integer value (or other integer) return the MI_ERROR status code	ids_dapip_0504.html#ids_dapip_0504
Functions that raise an exception	ids_dapip_0504.html#ids_dapip_0504