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/*
* Program type: API Interface
*
* Desription:
* This program demonstrates the reallocation of SQLDA
* and the 'isc_dsql_describe' statement. After a query
* is examined with 'isc_dsql_describe', an SQLDA of correct
* size is reallocated, and some information is printed about
* the query: its type (select, non-select), the number
* of columns, etc.
* The contents of this file are subject to the Interbase Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy
* of the License at http://www.Inprise.com/IPL.html
*
* Software distributed under the License is distributed on an
* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
* or implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code was created by Inprise Corporation
* and its predecessors. Portions created by Inprise Corporation are
* Copyright (C) Inprise Corporation.
*
* All Rights Reserved.
* Contributor(s): ______________________________________.
*/
#include <stdlib.h>
#include <string.h>
#include <ibase.h>
#include <stdio.h>
#include "example.h"
char *sel_str =
"SELECT department, mngr_no, location, head_dept \
FROM department WHERE head_dept in ('100', '900', '600')";
isc_db_handle DB = 0; /* database handle */
isc_tr_handle trans = 0; /* transaction handle */
ISC_STATUS_ARRAY status; /* status vector */
int main (int argc, char** argv)
{
int num_cols, i;
isc_stmt_handle stmt = NULL;
XSQLDA *sqlda;
char empdb[128];
if (argc > 1)
strcpy(empdb, argv[1]);
else
strcpy(empdb, "employee.fdb");
if (isc_attach_database(status, 0, empdb, &DB, 0, NULL))
{
ERREXIT(status, 1)
}
/* Allocate SQLDA of an arbitrary size. */
sqlda = (XSQLDA *) malloc(XSQLDA_LENGTH(3));
sqlda->sqln = 3;
sqlda->version = 1;
if (isc_start_transaction(status, &trans, 1, &DB, 0, NULL))
{
ERREXIT(status, 1)
}
/* Allocate a statement. */
if (isc_dsql_allocate_statement(status, &DB, &stmt))
{
ERREXIT(status, 1)
}
/* Prepare the statement. */
if (isc_dsql_prepare(status, &trans, &stmt, 0, sel_str, 1, sqlda))
{
ERREXIT(status, 1)
}
/* Describe the statement. */
if (isc_dsql_describe(status, &stmt, 1, sqlda))
{
ERREXIT(status, 1)
}
/* This is a select statement, print more information about it. */
printf("Query Type: SELECT\n\n");
num_cols = sqlda->sqld;
printf("Number of columns selected: %d\n", num_cols);
/* Reallocate SQLDA if necessary. */
if (sqlda->sqln < sqlda->sqld)
{
sqlda = (XSQLDA *) malloc(XSQLDA_LENGTH(num_cols));
sqlda->sqln = num_cols;
sqlda->version = 1;
/* Re-describe the statement. */
if (isc_dsql_describe(status, &stmt, 1, sqlda))
{
ERREXIT(status, 1)
}
num_cols = sqlda->sqld;
}
/* List column names, types, and lengths. */
for (i = 0; i < num_cols; i++)
{
printf("\nColumn name: %s\n", sqlda->sqlvar[i].sqlname);
printf("Column type: %d\n", sqlda->sqlvar[i].sqltype);
printf("Column length: %d\n", sqlda->sqlvar[i].sqllen);
}
if (isc_dsql_free_statement(status, &stmt, DSQL_drop))
{
ERREXIT(status, 1)
}
if (isc_commit_transaction(status, &trans))
{
ERREXIT(status, 1)
}
if (isc_detach_database(status, &DB))
{
ERREXIT (status, 1)
}
free(sqlda);
return 0;
}
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