cursor_upd.c

sybase linux or unix develope library package

/* Program Name : cursor_upd.c 
**
** Description  : This program uses a cursor to retrieve data from the 
**                'publishers' table in the 'pubs2' database. It retrieves 
**		  data row by row and prompts the user to input new values 
** 		  for the column 'state' in the 'publishers' table.
**
** Inputs       : value for the input parameter ( 'state' column from the
**                'publishers' table ) for the UPDATE.
**
** Script File 	: This program actually uses a copy of the publishers table
**		  ( called publishers2 ). Please run the script 
**		  cursor_upd.sql before running this program.
**
** References   : Open Client Reference manual pages for ct_cursor and also
**                ct_param.
**
*/
#include <stdio.h>
#include <ctpublic.h>
#include "./example.h"

#define RETURN_IF(a,b) if (a != CS_SUCCEED) \
	{fprintf(stdout,"error in %s\n",b); return a;}

#define EXIT_IF(a) if (a != CS_SUCCEED)\
	{fprintf(stdout,"FATAL error on line %d \n",__LINE__); exit(-1) ;}

/* Global variables */
#define MAX_COLUMN 	10 
#define MAX_COLSIZE 	255
#define MAX_COMMAND	255
char			rowbuffer[MAX_COLUMN][MAX_COLSIZE] ;

/* Function definitions */
CS_RETCODE	init_db PROTOTYPE((
						CS_CONTEXT	**
						));
						
CS_RETCODE	connect_db PROTOTYPE((
						CS_CONTEXT 	*,
						CS_CONNECTION   **,
						CS_CHAR		*,
						CS_CHAR		*
					    ));
CS_RETCODE 	cleanup_db PROTOTYPE((
						CS_CONTEXT	*,
						CS_RETCODE	 
					    ));
CS_RETCODE	send_sql PROTOTYPE((
						CS_COMMAND	*,
						CS_CHAR		*
				  	    ));
CS_RETCODE	handle_returns PROTOTYPE((
						CS_COMMAND	*
					    ));
CS_RETCODE 	bind_columns PROTOTYPE((
						CS_COMMAND	*
					    ));
CS_RETCODE	fetch_n_print PROTOTYPE((
						CS_COMMAND	*
				            ));
CS_RETCODE 	open_cursor PROTOTYPE((
						CS_COMMAND	*
						));

CS_RETCODE 	single_row PROTOTYPE((
						CS_COMMAND	*
						));
extern CS_RETCODE CS_PUBLIC   	ctlib_client_msg_handler PROTOTYPE((
						CS_CONTEXT	*,
						CS_CONNECTION 	*,
						CS_CLIENTMSG	*
						));
extern CS_RETCODE CS_PUBLIC   	ctlib_server_msg_handler PROTOTYPE((
						CS_CONTEXT	*,
						CS_CONNECTION 	*,
						CS_SERVERMSG	*
						));


int main()
{
	CS_CONTEXT	*cntx_ptr ;
	CS_CONNECTION	*conn_ptr ;
	CS_COMMAND	*cmd_ptr ;
	CS_RETCODE	ret ;
	CS_INT		command_type ;

		/* Allocate a context and initialize client-library */
	ret = init_db(&cntx_ptr);
	  EXIT_IF(ret);

		/* Establish a connection to the server */
	ret = connect_db (cntx_ptr, &conn_ptr, EX_USERNAME, EX_PASSWORD);
	  EXIT_IF(ret);
	
		/* Allocate a command structure */
	ret = ct_cmd_alloc (conn_ptr, &cmd_ptr );
	  EXIT_IF(ret);

		/* Perform cursor operations */
	ret = open_cursor ( cmd_ptr );
	  EXIT_IF(ret);

		/* Drop the command structure */
	ret = ct_cmd_drop ( cmd_ptr );
	  EXIT_IF(ret);

		/* Close connection to the server */
	ret = ct_close ( conn_ptr, CS_UNUSED ) ;	
	  EXIT_IF(ret);

		/* Drop the context and perform cleanup */
	ret = cleanup_db (cntx_ptr, ret );
 		EXIT_IF (ret);

	printf("\n End of program run! \n");
	exit(0);
}

CS_RETCODE 	init_db (cntx_ptr)
CS_CONTEXT	**cntx_ptr ;
{
	CS_RETCODE	retcode ;

			/* allocate a context */
	retcode = cs_ctx_alloc (CS_VERSION_100,cntx_ptr );
		RETURN_IF ( retcode, "cs_ctx_alloc ");

			/* initialize the library */
	retcode = ct_init (*cntx_ptr, CS_VERSION_100 );
		RETURN_IF ( retcode, "ct_init ");

			/* install the server message callback */
	retcode = ct_callback ( *cntx_ptr, NULL, CS_SET, CS_SERVERMSG_CB,
				(CS_VOID *)ctlib_server_msg_handler) ;
		RETURN_IF ( retcode, "ct_callback ");

			/* install the client message callback */
	retcode = ct_callback (*cntx_ptr, NULL, CS_SET, CS_CLIENTMSG_CB,
				(CS_VOID *)ctlib_client_msg_handler);
		RETURN_IF ( retcode, "ct_callback: CLIENTMSG ");

	return retcode ;
}

CS_RETCODE 	cleanup_db ( cntx_ptr, status )
CS_CONTEXT	*cntx_ptr ;
CS_RETCODE	status ;
{
	CS_RETCODE	retcode ;
	CS_INT		exit_type ;

	exit_type = ( status != CS_SUCCEED ) ? CS_FORCE_EXIT : CS_UNUSED ;

		 /* close and cleanup connection to the server */
	retcode = ct_exit (cntx_ptr, exit_type );
		RETURN_IF ( retcode, "db_cleanup:ct_exit ");

		 /* drop the context */
	retcode = cs_ctx_drop (cntx_ptr) ;
		RETURN_IF ( retcode, "db_cleanup:cs_drop ");

	return retcode ; 
}	

CS_RETCODE	connect_db (cntx_ptr, conn_ptr, user_name, password )
CS_CONTEXT	*cntx_ptr ;
CS_CONNECTION	**conn_ptr ;
CS_CHAR		*user_name, *password ;
{
	CS_RETCODE	retcode ;

		 /* Allocate a connection pointer */
	retcode = ct_con_alloc (cntx_ptr, conn_ptr );
		RETURN_IF ( retcode, "connect_db: ct_con_alloc ");

		/* Set the username and password properties */
	retcode = ct_con_props ( *conn_ptr, CS_SET, CS_USERNAME, user_name,
					CS_NULLTERM, NULL );
		RETURN_IF ( retcode, "connect_db: ct_con_props: username ");

	retcode = ct_con_props ( *conn_ptr, CS_SET, CS_PASSWORD, password,
					CS_NULLTERM, NULL );
		RETURN_IF ( retcode, "connect_db: ct_con_props: password"); 

		 /* connect to the server */
	retcode = ct_connect ( *conn_ptr, NULL, 0 ) ;
		RETURN_IF ( retcode, "connect_db: ct_connect ") ;

	return  CS_SUCCEED ;
}

CS_RETCODE	handle_returns ( cmd_ptr )
CS_COMMAND	*cmd_ptr ;
{
	CS_RETCODE	results_ok ;
	CS_INT		result_type ;

		 /* Process all returned result types */
	while (( results_ok = ct_results ( cmd_ptr, &result_type)) == CS_SUCCEED )
	{
		switch ((int)result_type)
		{
			case CS_ROW_RESULT:
				  printf("TYPE: ROW RESULT \n");
				  results_ok = bind_columns ( cmd_ptr );
				  RETURN_IF ( results_ok, "bind columns");
		
				  results_ok = fetch_n_print ( cmd_ptr );
				  RETURN_IF ( results_ok, "fetch_n_print");
				  break ;

			case CS_CMD_SUCCEED:	
				  printf("TYPE: CMD SUCCEEDED \n");
				  break ;

			case CS_CMD_DONE   :
				  printf("TYPE : CMD DONE \n");
				  break ;

			case CS_CMD_FAIL   :
				  printf("TYPE: CMD FAIL \n");
				  break ;

			case CS_CURSOR_RESULT :
				  printf("TYPE: CURSOR RESULT ");
				  results_ok = bind_columns ( cmd_ptr );
				  RETURN_IF(results_ok, "bind columns");
				  results_ok = fetch_n_print(cmd_ptr);
				  RETURN_IF ( results_ok, "fetch n print");
				  break ;

			default    :
				  RETURN_IF ( CS_FAIL, "unknown results \n");
				  break ;
		} ;
	}
	if ( results_ok == CS_END_RESULTS )
	 	return CS_SUCCEED ;
	return CS_FAIL ;
}

CS_RETCODE 	bind_columns (cmd_ptr )
CS_COMMAND	*cmd_ptr ;
{
	CS_RETCODE	retcode ;
	CS_INT		i , num_cols ;
	CS_DATAFMT	target_format ;

	retcode = ct_res_info( cmd_ptr, CS_NUMDATA, &num_cols, 
			       CS_UNUSED, NULL);
		RETURN_IF ( retcode, "ct_bind : ct_res_info ");

	for ( i = 1 ; i <= num_cols ; i++ )
	{
		memset ( &target_format, 0, CS_SIZEOF(target_format)) ;

		target_format.datatype = CS_CHAR_TYPE ;
		target_format.maxlength = MAX_COLSIZE  ;
		target_format.count    = 1 ;
		target_format.format   = CS_FMT_NULLTERM ;

			 /* Bind returned data to host variables */
		retcode = ct_bind (cmd_ptr, i, &target_format, rowbuffer[i-1],
					NULL, NULL ) ;

		RETURN_IF ( retcode, "bind_columns: ct_bind ");
	}
	return CS_SUCCEED ;
}

CS_RETCODE	fetch_n_print ( cmd_ptr )
CS_COMMAND	*cmd_ptr ;
{
	CS_RETCODE 	retcode ;
	CS_INT		i, num_cols ;
	
	retcode = ct_res_info(cmd_ptr, CS_NUMDATA, &num_cols, CS_UNUSED,NULL);
		RETURN_IF ( retcode, "fetch_n_print: ct_res_info ");

		 /* Fetch the bound data into host variables */
	while (( (retcode = ct_fetch(cmd_ptr, CS_UNUSED, CS_UNUSED, CS_UNUSED,
				(CS_INT *)NULL)) == CS_SUCCEED )	
	||
	      ( retcode == CS_ROW_FAIL ))
	{
		if ( retcode == CS_ROW_FAIL )
		{
			printf("ct_fetch returned row fail \n");
			continue ;
		}

		for ( i = 1 ; i <= num_cols ; i++ )
		{
			printf(" %s \t ", rowbuffer[i-1] );
		}
 		printf("\n");
		single_row( cmd_ptr );
	}

	if ( retcode != CS_END_DATA)
		RETURN_IF ( retcode, "fetch_n_print ") ;
	
	return CS_SUCCEED ;
}

CS_RETCODE open_cursor ( cmd_ptr )
CS_COMMAND	*cmd_ptr ;
{
	CS_RETCODE	ret ;
	CS_CHAR		state[3]; 
	CS_DATAFMT	datafmt ;

	ret = ct_cursor ( cmd_ptr, CS_CURSOR_DECLARE, "browse_cursor",
			  CS_NULLTERM, "select * from pubs2.dbo.publishers2", 
			  CS_NULLTERM, CS_FOR_UPDATE );
		RETURN_IF ( ret, "ct_cursor: declare ");

	ret = ct_cursor ( cmd_ptr, CS_CURSOR_OPEN, NULL, CS_UNUSED, NULL,
			CS_UNUSED, CS_UNUSED );
		RETURN_IF ( ret, "ct_cursor: open "); ;

	ret = ct_send ( cmd_ptr );
		RETURN_IF ( ret, "ct_send : cursors ");

	ret = handle_returns ( cmd_ptr ) ;
		RETURN_IF ( ret, "ct_results : cursors ");

	ret = ct_cursor( cmd_ptr, CS_CURSOR_CLOSE, NULL, CS_UNUSED,
			 NULL, CS_UNUSED, CS_DEALLOC);
			RETURN_IF ( ret, "ct_cursor:close ");

	ret = ct_send ( cmd_ptr );
		RETURN_IF ( ret, "ct_send : cursor close ");

	ret = handle_returns ( cmd_ptr ) ;
		RETURN_IF ( ret, "ct_results : cursor close");

	return CS_SUCCEED ;
}

CS_RETCODE single_row ( cmd_ptr )
CS_COMMAND	*cmd_ptr ;
{
		CS_RETCODE	retcode ;
		CS_DATAFMT	datafmt ;
		CS_INT		i, num_cols, result_type ;
		CS_CHAR		sqlstmt[70] , state[3];


		printf("New state: ");
		gets(state);
		if ( strlen(state) < 1 )
		{
			/* If the user hit 'enter' for the new input value, 
			** don't bother updating.Return to the calling function.
			*/
			return CS_SUCCEED;
		}

		strcpy(sqlstmt,"update pubs2.dbo.publishers2 set state = @state ");
		retcode = ct_cursor(cmd_ptr, CS_CURSOR_UPDATE,
				 "pubs2.dbo.publishers2", CS_NULLTERM,
				  sqlstmt, CS_NULLTERM, CS_UNUSED ) ;
		  RETURN_IF ( retcode, "ct_cursor; update ");

		/* Set up the parameters for the update */
		memset(&datafmt, 0, sizeof (datafmt));
		strcpy(datafmt.name, "@state");
    		datafmt.namelen = CS_NULLTERM;
    		datafmt.datatype = CS_CHAR_TYPE;
    		datafmt.maxlength = CS_UNUSED;
    		datafmt.status = CS_INPUTVALUE;
    		datafmt.locale = NULL;
 
		/* If an input value was entered, do the update. */
    		retcode = ct_param(cmd_ptr, &datafmt, (CS_VOID *)state,
       		         strlen(state), CS_UNUSED) ;
			RETURN_IF( retcode, "ct_param ");

		retcode = ct_send (cmd_ptr) ;
			RETURN_IF ( retcode, "ct_cursor:ct_send ");
		
		retcode = handle_returns ( cmd_ptr );
			RETURN_IF ( retcode, "ct_cursor:ct_results ");

	return CS_SUCCEED ;
}