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127 lines
3.0 KiB
Plaintext
127 lines
3.0 KiB
Plaintext
/*
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* Program type: Embedded Dynamic SQL
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*
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* Description:
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* This program demonstrates the reallocation of SQLDA and
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* the 'describe' statement. After a query is examined with
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* 'describe', an SQLDA of correct size is reallocated, and some
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* information is printed about the query: its type (select,
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* non-select), the number of columns, etc.
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* The contents of this file are subject to the Interbase Public
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* License Version 1.0 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy
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* of the License at http://www.Inprise.com/IPL.html
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*
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* Software distributed under the License is distributed on an
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* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
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* or implied. See the License for the specific language governing
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* rights and limitations under the License.
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*
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* The Original Code was created by Inprise Corporation
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* and its predecessors. Portions created by Inprise Corporation are
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* Copyright (C) Inprise Corporation.
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*
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* All Rights Reserved.
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* Contributor(s): ______________________________________.
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*/
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#include "example.h"
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#include <stdlib.h>
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#include <string.h>
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char *sel_str =
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"SELECT department, mngr_no, location, head_dept \
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FROM department WHERE head_dept in ('100', '900', '600')";
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char Db_name[128];
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EXEC SQL
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SET DATABASE empdb = "employee.fdb" RUNTIME :Db_name;
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int main(int argc, char** argv)
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{
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short num_cols, i;
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XSQLDA *sqlda;
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if (argc > 1)
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strcpy(Db_name, argv[1]);
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else
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strcpy(Db_name, "employee.fdb");
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EXEC SQL
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WHENEVER SQLERROR GO TO Error;
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EXEC SQL
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CONNECT empdb;
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EXEC SQL
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SET TRANSACTION;
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/* Allocate SQLDA of an arbitrary size. */
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sqlda = (XSQLDA *) malloc(XSQLDA_LENGTH(4));
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sqlda->sqln = 4;
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sqlda->sqld = 4;
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sqlda->version = 1;
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/* Prepare an unknown statement. */
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EXEC SQL
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PREPARE q INTO SQL DESCRIPTOR sqlda FROM :sel_str;
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/* Describe the statement. */
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EXEC SQL
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DESCRIBE q INTO SQL DESCRIPTOR sqlda;
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/* This is a non-select statement, which can now be executed. */
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if (sqlda->sqld == 0)
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return(0);
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/* If this is a select statement, print more information about it. */
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else
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printf("Query Type: SELECT\n\n");
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num_cols = sqlda->sqld;
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printf("Number of columns selected: %d\n", num_cols);
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/* Reallocate SQLDA if necessary. */
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if (sqlda->sqln < sqlda->sqld)
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{
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free(sqlda);
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sqlda = (XSQLDA *) malloc(XSQLDA_LENGTH(num_cols));
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sqlda->sqln = num_cols;
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sqlda->sqld = num_cols;
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/* Re-describe the statement. */
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EXEC SQL
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DESCRIBE q INTO SQL DESCRIPTOR sqlda;
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num_cols = sqlda->sqld;
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}
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/* List column names, types, and lengths. */
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for (i = 0; i < num_cols; i++)
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{
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printf("\nColumn name: %s\n", sqlda->sqlvar[i].sqlname);
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printf("Column type: %d\n", sqlda->sqlvar[i].sqltype);
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printf("Column length: %d\n", sqlda->sqlvar[i].sqllen);
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}
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EXEC SQL
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COMMIT;
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EXEC SQL
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DISCONNECT empdb;
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free( sqlda);
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return(0);
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Error:
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isc_print_status(gds__status);
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printf("SQLCODE=%d\n", SQLCODE);
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return(1);
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}
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