Using dynamic SQL Method 4 to connect Oracle implementations (version 1.0)

Summary

The 4th method of dynamic SQL uses Sqlda (the SQL Descriptor area) and Oracle to Exchange data to perform SQL statements that do not know the number and type of select table entries or virtual input host variables until the program is run.

Module Oracle's data

Jmp_buf	Jmp_continue		Save Program Breakpoint
file*	Orain	Stdin	Default input source
file*	Oraout	StdOut	Default output source
Int	Oraresult	0	Error flag
char*	Dml_commands[]	Slightly	Data Manipulation Statement Verb table
Oraquery	Query		Wrapping SQL Execution Process
Oraquerybase	Pquery	&query	Provide an external interface

interface with the external

• Orain,oraout: The application changes the input and output source of the Oracle module by manipulating the two variables.
• Oraresult:oracle the execution result of the module (to be subdivided for error reasons).
• Oraconnect (User,password), Oradisconnect (): Establishes and disconnects from the database and must establish a connection before any SQL statements are executed.
• Jmp_for_error (label): If an Oracle module error occurs, go to the label label to continue execution, except when the connection is established.
• oraquerybase* Pquery: See the description of the abstract class Oraquerybase.

Abstract class Oraquerybase

Return data type	Method name	Parameters	Describe
Int	Set	Int,int,int	To set the size of the SQL description area
Int	Alloc		Assigning SQL Description Area
Int	Get_statement		Reading SQL statements from an input source
Int	Set_statement]	Const char*	Enter SQL statements in string format
Int	Execute		Execute the prepared SQL statement
Int	Free		Releasing the SQL Description area

Resources

"Programmer ' Guide to the Oracle precompilers" release 1.8

C + + Advanced reference manual