DB2 Server for VSE & VM: Application Programming

Using Stored Procedures

Figure 116 shows how to define the parameters in a stored procedure that uses the GENERAL linkage convention.

• argv contains an array of pointers to the parameters that were passed to the stored procedure.
  • argv[0] is a special entry containing the address of the stored procedure name
  • argv[1] contains the address of parameter 1
  • argv[2] contains the address of parameter 2
• argc contains the number of parameters that were passed to the stored procedure, plus one to account for the procedure name which is passed in argv[0].

Figure 116. Stored Procedure - Using GENERAL Linkage Convention

#pragma options(RENT) #pragma runopts(PLIST(OS)) #include <stdlib.h> #include <stdio.h> /*****************************************************************/ /* Code for a C language stored procedure that uses the */ /* GENERAL linkage convention. */ /*****************************************************************/ main(argc,argv) int argc; /* Number of parameters passed */ char *argv[]; /* Array of strings containing */ /* the parameter values */ { long int locv1; /* Local copy of V1 */ char locv2[10]; /* Local copy of V2 */ /* (null-terminated) */ . . . /***************************************************************/ /* Get the passed parameters. */ /***************************************************************/ if(argc==3) /* Should get 3 parameters: */ { /* procname, V1, V2 */ locv1 = *(int *) argv[1]; /* Get local copy of V1 */ . . . strcpy(argv[2],locv2); /* Assign a value to V2 */ . . . } }

Figure 117 shows how to define the parameters in a stored procedure that uses the GENERAL WITH NULLS linkage convention. In this case:

• argv[0] contains the address of the stored procedure name
• argv[1] contains the address of parameter 1
• argv[2] contains the address of parameter 2
• argv[n] contains the address of parameter n
• argv[n+1] contains the address of the indicator variable array

Figure 117. Stored Procedure - Using GENERAL WITH NULLS Linkage Convention

#pragma runopts(PLIST(OS)) #include <stdlib.h> #include <stdio.h> /*****************************************************************/ /* Code for a C language stored procedure that uses the */ /* GENERAL WITH NULLS linkage convention. * /*****************************************************************/ main(argc,argv) int argc; /* Number of parameters passed */ char *argv[]; /* Array of strings containing */ /* the parameter values */ { long int locv1; /* Local copy of V1 */ char locv2[10]; /* Local copy of V2 */ /* (null-terminated) */ short int locind[2]; /* Local copy of indicator */ /* variable array */ short int *tempint; /* Used for receiving the */ /* indicator variable array */ . . . /***************************************************************/ /* Get the passed parameters. */ /***************************************************************/ if(argc==4) /* Should get 4 parameters: */ { /* procname, V1, V2, */ /* indicator variable array */ locv1 = *(int *) argv[1]; /* Get local copy of V1 */ tempint = argv[3]; /* Get pointer to indicator */ /* variable array */ locind[0] = *tempint; /* Get 1st indicator variable */ locind[1] = *(++tempint); /* Get 2nd indicator variable */ if(locind[0]<0) /* If 1st indicator variable */ { /* is negative, V1 is null */ . . . } . . . strcpy(argv[2],locv2); /* Assign a value to V2 */ *(++tempint) = 0; /* Assign 0 to V2's indicator */ /* variable */ } }