Re: Embedded SQL in a DLL

From: Jerome Carron <jcarron_at_ca.oracle.com>
Date: 1996/11/11
Message-ID: <3287ab26.28028032_at_newshost.us.oracle.com>#1/1

On 7 Nov 1996 21:58:59 GMT, Norwood Story <Norwood_S_at_shared.com> wrote:

>I am trying to convert a C program with embedded SQL into a DLL on NT.
>The program works as a DLL for Sybase and Informix. I have modified the
>code accordingly for Oracle, but it will not initialize properly. I am
>having trouble finding any documentation that helps. I have the sample
>programs that have the embedded SQL in them working fine.
>
>Any help would be greatly appreciated!
>
>Thanks!
>

Specifically what problems are you having and what are you calling the DLL function from. Here is a sample of some code to connect to the DB using Pro*C. The funtion definitions in the DLL can be done differently, but this was to be called from VB4.

#include <stdio.h>
#include <string.h>
#ifdef WIN_NT
# include <string.h>
# include <stdlib.h>
# include "sqlproto.h"
#endif /* WIN_NT */

#ifdef TRUE
#	undef TRUE

#endif
#define TRUE 1

/* Maximum number of select-list items or bind variables. */ #define MAX_ITEMS 40

/* Maximum lengths of the _names_ of the

   select-list items or indicator variables. */

#define MAX_VNAME_LEN     30
#define MAX_INAME_LEN     30

#ifndef NULL

#define NULL 0
#endif

typedef char asciz;

char *dml_commands[] = {"SELECT", "select", "INSERT", "insert",

                        "UPDATE", "update", "DELETE", "delete"};

EXEC SQL BEGIN DECLARE SECTION;
	EXEC SQL TYPE asciz IS STRING(30);
	VARCHAR		uid1[30];
	VARCHAR		pwd1[30];
	VARCHAR		con1[30];
	VARCHAR     sqlstmt[200];
	VARCHAR     cname[30];
	asciz       tname[10][30];
	char        sql_statement[1024];
	char        update_buf[1024];
	int         row_count;

    EXEC SQL VAR sql_statement IS STRING(1024); EXEC SQL END DECLARE SECTION; EXEC SQL INCLUDE sqlca;
EXEC SQL INCLUDE sqlda;

SQLDA *bind_dp;
SQLDA *select_dp;

extern SQLDA *sqlald();
extern void sqlnul();

/* Define a buffer to hold longjmp state info. */ /*jmp_buf jmp_continue;*/

/* A global flag for the error routine. */ int parse_flag = 0;
/* A global flag for determining if call if for a VIEW or TABLE */ int vtflag =0;
/* A global for dump file record separator, could be done as a passed pointer */
/* can't be bothered for now */
char spchr;

__declspec(dllexport) void ConnectDB(char *uid, char *pwd, char *con, char *err_code)

	{
		int i;
        	char msg_buf[100];
		int buf_size=100;
		int msg_len;
			
        		strcpy(uid1.arr, uid);
        		uid1.len=strlen(uid1.arr);	
		strcpy(pwd1.arr, pwd);
		pwd1.len=strlen(pwd1.arr);
		strcpy(con1.arr, con);
		con1.len=strlen(con1.arr);

		EXEC SQL CONNECT :uid1 IDENTIFIED BY :pwd1 USING
:con1;
		if(sqlca.sqlcode != 0)
		{
/*			sqlglm(msg_buf, &buf_size, &msg_len);
	   		msg_buf[msg_len] = '\0';

			strcpy(err_code, msg_buf);		*/
			sprintf(msg_buf, "%d", sqlca.sqlcode);
			strcpy (err_code, msg_buf);
		}
		else
		{
			strcpy(msg_buf, "YES");
			strcpy(err_code, msg_buf);
		}
 
	}

Hope this helps,
Jc. Received on Mon Nov 11 1996 - 00:00:00 CET