Tricks of the Windows Gam…ming Gurus (2nd Edition)/Disc2.iso/msdn_vcb/samples/vc98/sdk/dbmsg/sql/dblib/c/example1/example1.c

C/C++ Source or Header | 1996-04-03 | 5.1 KB | 193 lines

/*    example1.c */
/*
**    This example illustrates how to send two queries to
**    SQL Server in a command batch.    It binds each set
**    of results and prints the rows.
**
*/

#if defined(DBNTWIN32)
#include <windows.h>
#endif

#include <stdio.h>
#include <sqlfront.h>
#include <sqldb.h>

#define DATELEN    26
#define TYPELEN    2

/* Forward declarations of the error handler and message handler.
*/
int err_handler(DBPROCESS*, int, int, int, char*, char*);
int msg_handler(DBPROCESS*, DBINT, int, int, char*);

main(argc, argv)
int    argc;
char    *argv[];
{
    DBPROCESS    *dbproc;    /* Our connection with SQL Server. */
    LOGINREC    *login;    /* Our login information. */

    /* These are the variables used to store the returning data. */

    DBCHAR    crdate[DATELEN+1];
    DBINT    id;
    DBCHAR    name[MAXNAME+1];    /* MAXNAME is defined in
    * "sqldb.h" as the maximum
    * length for names of database
    * objects, such as tables,
    * columns, and procedures.
    */
    DBCHAR    type[TYPELEN+1];
    RETCODE    result_code;

        dbinit();        /* initialize dblib */

    /* Install the user-supplied error-handling and message-handling
    * functions. They are defined at the bottom of this source file.
    */
    dbmsghandle((DBMSGHANDLE_PROC)msg_handler);
    dberrhandle((DBERRHANDLE_PROC)err_handler);

    /*
    ** Get a LOGINREC structure and fill it with the necessary
    ** login information.
    */

    login = dblogin();
    DBSETLUSER(login, "user");
    DBSETLPWD(login, "my_passwd");
    DBSETLAPP(login, "example1");
    DBSETLVERSION(login, DBVER60);

    /*
    ** Get a DBPROCESS structure for communicating with SQL Server.
    */

    dbproc = dbopen(login, "my_server");

    /*
    ** We are going to retrieve some information from a table
    ** named "sysobjects", regarding names of system tables and
    ** stored procedures.
    ** We will submit two queries.    The first finds all the rows
    ** that describe system tables.    The second finds all the rows
    ** that describe stored procedures.    The program will only look
    ** at the first 10 rows that describe stored procedures.
    */

    /* First, put the commands into the command buffer. */

    dbcmd(dbproc, "select name, type, id, crdate from sysobjects");
    dbcmd(dbproc, " where type = 'S' ");
    dbcmd(dbproc, "select name, type, id, crdate from sysobjects");
    dbcmd(dbproc, " where type = 'P' ");

    /*
    ** SQL Server processes the command batch in the following
    ** order:
    **
    ** 1)    It checks for syntax errors (i.e., "use database pubs"
    **        is syntactically incorrect; it should be "use pubs").
    ** 2)    The second check is a semantic check (i.e., "select * from
    **        titels" is incorrect because the spelling should be
    **        "titles".)
    ** 3) The third check occurs in the actual execution phase. This
    **    check involves issues like permissions or memory problems.
    **
    ** In the execution phase, dbsqlexec() and dbresults() can return
    ** the value "SUCCEED", which means there are more commands in the
    ** batch to process and that command was successful. A value
    ** of "FAIL" means that the query failed but there may be more
    ** commands in the batch to process. A value of "NO_MORE_RESULTS"
    ** means that there are no more commands in the batch to process.
    ** Therefore, the programmer must check the return values after
    ** dbsqlexec() and dbresults(), as illustrated below.
    **
    */

    /* Send the commands to SQL Server and start execution. */
    dbsqlexec(dbproc);

    /* Process each command until there are no more. */

    while ((result_code = dbresults(dbproc)) != NO_MORE_RESULTS)
    {
        if (result_code == SUCCEED)
        {
            /* Bind program variables. */

            dbbind(dbproc, 1, NTBSTRINGBIND, (DBINT) 0, name);
            dbbind(dbproc, 2, NTBSTRINGBIND, (DBINT) 0, type);
            dbbind(dbproc, 3, INTBIND, (DBINT) 0, (BYTE *) &id);
            dbbind(dbproc, 4, NTBSTRINGBIND, (DBINT) 0, crdate);

            /* Print appropriate header for the type of
            * data coming back.
            */

            printf("\n %s Objects: \n\n",
            DBCURCMD(dbproc) == 1 ? "System Table": "Procedure");

            /* Now print the rows. */

            while (dbnextrow(dbproc) != NO_MORE_ROWS)
            {
                /*
                ** If this is the 2nd command and
                ** 10th row, flush the rest of the
                ** rows for that command.
                */

                if ((DBCURCMD(dbproc) == 2)
                && (DBCURROW(dbproc) > 10))
                                    continue;

                printf
                ("%s %s %ld %s\n", name, type, id, crdate);
            }
        }
    }


    /* Close our connection and exit the program. */

    dbexit();
    return(STDEXIT);
}

int err_handler(dbproc, severity, dberr, oserr, dberrstr, oserrstr)
DBPROCESS    *dbproc;
int    severity;
int    dberr;
int    oserr;
char    *dberrstr;
char    *oserrstr;
{
    printf("DB-LIBRARY error:\n\t%s\n", dberrstr);

    if (oserr != DBNOERR)
        printf("Operating-system error:\n\t%s\n", oserrstr);

    if ((dbproc == NULL) || (DBDEAD(dbproc)))
        return(INT_EXIT);

    return(INT_CANCEL);
}

int msg_handler(dbproc, msgno, msgstate, severity, msgtext)
DBPROCESS    *dbproc;
DBINT    msgno;
int    msgstate;
int    severity;
char    *msgtext;
{
    printf
    ("SQL Server message %ld, state %d, severity %d:\n\t%s\n",
    msgno, msgstate, severity, msgtext);
    return(0);
}