/**********************************************************************
* FILENAME : CallSPFindName.c
*
* DESCRIPTION :
* Simple ODBC example to SELECT data from a table via a stored
* procedure where two arrays of parameters are used, one
* containing FirstNames and one contining offsets into the
* FirstNames array. As each FirstName is processed the matching
* offset value is passed back as the stored procedure return
* value. This can then be used by the calling program to identify
* which element in the FirstNames array was used to generate the
* results set.
*
* The stored procedure has 3 parameters,
* in the form :
*
* {? = CALL Find_ByName(?, ?)}
*
* If the Firstnames array contains "a","b","c","d" and the
* offsets array contains 0,1,2,3, we get, for each Firstname,
* the result set with the return value equal to the offset into
* the firstnamess array that produced the result set. For "a"s,
* we 0, "b"s we get 1, etc. In that way we can tie a results set
* back to the data that produced it.
*
* ODBC USAGE :
* Calls DropProcedure (), CreateProcedure () and ListProcedure ()
* to recreate and display the stored procedure 'Find_ByName'.
* SQLSetStmtAttr - to set : SQL_ATTR_PARAMSET_SIZE
* SQL_ATTR_PARAM_STATUS_PTR
* SQL_ATTR_PARAMS_PROCESSED_PTR
* SQLBindParameter - to bind 3 paramaters for the stored proc :
* Param 1 - RetParam - proc return variable
* Param 2 - pFirstNames array
* Param 3 - pFirstNameIXs array
* SQLExecDirect - to execute the stored procedure
* Loops using SQLNumResultCols(), SQLFetch(), SQLRowCount()
* and SQLMoreResults() to retrieve results sets generated by
* stored procedure.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sql.h>
#include <sqlext.h>
#include <string.h>
#include "util.c"
#include "CallSPUtil.c"
#define PARAM_ARRAY_SIZE 20 // Number of params in param array
int main () {
SQLHENV henv = SQL_NULL_HENV; // Environment
SQLHDBC hdbc = SQL_NULL_HDBC; // Connection handle
SQLHSTMT hstmt = SQL_NULL_HSTMT; // Statement handle
SQLRETURN retcode; // Return status
// return index pPersonIXs[param no] from stored Proc
SQLCHAR * strCallSP = "{? = CALL Find_ByName(?, ?)}";
char * strProcName = "Find_ByName";
SQLSMALLINT columns; // Number of columns in result-set
int i, count;
SQLCHAR pFirstNames [PARAM_ARRAY_SIZE][2] =
{"a","b","c","d","e","f","g","h","i","j",
"k","l","m","n","o","p","q","r","s","t",};
SQLINTEGER pFirstNameIXs [PARAM_ARRAY_SIZE] =
{0,1,2,3,4,5,6,7,8,9,
10,11,12,13,14,15,16,17,18,19};
SWORD RetParam;
SQLLEN cbRetParam, lenFirstName;
SQLUSMALLINT ParamStatusArray[PARAM_ARRAY_SIZE];
SQLINTEGER ParamsProcessed=0;
// Allocate an environment handle
retcode=SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
CHECK_ERROR(retcode, "SQLAllocHandle(ENV)", henv, SQL_HANDLE_ENV);
// Set ODBC Version
retcode=SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION,
(void *) SQL_OV_ODBC3, 0);
CHECK_ERROR(retcode, "SQLSetEnvAttr(SQL_ATTR_ODBC_VERSION)",
henv, SQL_HANDLE_ENV);
// Allocate a connection handle
retcode=SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_DBC)",
hdbc, SQL_HANDLE_DBC);
// DSN
retcode=SQLDriverConnect(hdbc, NULL, "DSN=DATASOURCE;", SQL_NTS,
NULL, 0, NULL, SQL_DRIVER_COMPLETE);
CHECK_ERROR(retcode, "SQLDriverConnect(DATASOURCE)",
hdbc, SQL_HANDLE_DBC);
retcode = DropProcedure (hdbc, strProcName);
retcode = CreateProcedure (hdbc, strProcName);
retcode = ListProcedure (hdbc, strProcName);
// Allocate a statement handle
retcode=SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);
CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_STMT)",
hstmt, SQL_HANDLE_STMT);
// setup for parameter array processing
retcode = SQLSetStmtAttr (hstmt, SQL_ATTR_PARAMSET_SIZE,
(SQLPOINTER) PARAM_ARRAY_SIZE, 0);
retcode = SQLSetStmtAttr (hstmt, SQL_ATTR_PARAM_STATUS_PTR,
ParamStatusArray, PARAM_ARRAY_SIZE);
retcode = SQLSetStmtAttr (hstmt, SQL_ATTR_PARAMS_PROCESSED_PTR,
&ParamsProcessed, 0);
// Bind the output parameter to variable RetParam.
retcode = SQLBindParameter(hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_SSHORT,
SQL_INTEGER, 0, 0, &RetParam, 0, &cbRetParam);
CHECK_ERROR(retcode, "SQLBindParameter(1)",
hstmt, SQL_HANDLE_STMT);
// Bind array values of parameter 2 data in
retcode = SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR,
SQL_VARCHAR, 2, 0, pFirstNames, 2, NULL);
CHECK_ERROR(retcode, "SQLBindParameter(2)",
hstmt, SQL_HANDLE_STMT);
// Bind array values of parameter 3 data in
retcode = SQLBindParameter(hstmt, 3, SQL_PARAM_INPUT, SQL_C_LONG,
SQL_INTEGER, 0, 0, pFirstNameIXs, 0, NULL);
CHECK_ERROR(retcode, "SQLBindParameter(3)",
hstmt, SQL_HANDLE_STMT);
retcode = SQLExecDirect (hstmt, strCallSP, SQL_NTS);
CHECK_ERROR(retcode, "SQLExecDirect(SQL_HANDLE_STMT)",
hstmt, SQL_HANDLE_STMT);
printf ("\nPersonID Firstname Surname Address City");
printf ("\n---------- --------- ------- ------- ----\n");
SQLLEN indicator, RowCount;
char *buf=malloc (255);
do {
// SQLNumResultCols() returns number of columns in result set.
// if non zero use SQLFetch until SQL_NO_DATA returned
retcode=SQLNumResultCols(hstmt, &columns);
CHECK_ERROR(retcode, "SQLNumResultCols()", hstmt, SQL_HANDLE_STMT);
if (columns > 0) {
printf ("\nRows ...");
while (SQLFetch(hstmt) != SQL_NO_DATA) {
// Loop through the columns
memset (buf, ' ', 255);
printf ("\n");
for (i = 1; i <= columns; i++) {
// retrieve column data as a string
retcode = SQLGetData(hstmt, i, SQL_C_CHAR,
buf, 255, &indicator);
if (SQL_SUCCEEDED(retcode)) {
// Handle null columns
if (indicator == SQL_NULL_DATA)
strcpy (buf, "NULL");
buf=rtrim(buf, ' ');
printf("%10s ", buf);
}
}
}
printf ("\nEnd ...");
}
else {
// SQLRowCount returns number of rows affected by INSERT, UPDATE,
// DELETE or (if supported by the driver) number of rows returned
// by a SELECT
retcode=SQLRowCount(hstmt, &RowCount);
CHECK_ERROR(retcode, "SQLRowCount()", hstmt, SQL_HANDLE_STMT);
printf ("\nFirstname offset was : %i\nSelected using : %s",
RetParam, pFirstNames[RetParam]);
}
if (columns==0) {
printf ("\n-----------");
}
} while ((retcode=SQLMoreResults(hstmt)) == SQL_SUCCESS);
// After SQLMoreResults() returns SQL_NO_DATA,
if (retcode==SQL_NO_DATA && columns>0) {
printf ("\nFirstname offset was : %i\nSelected using : %s",
RetParam, pFirstNames[RetParam]);
printf ("\n-----------");
}
exit:
free (buf);
printf ("\nComplete.\n");
// Free handles
// Statement
if (hstmt != SQL_NULL_HSTMT)
SQLFreeHandle(SQL_HANDLE_STMT, hstmt);
// Connection
if (hdbc != SQL_NULL_HDBC) {
SQLDisconnect(hdbc);
SQLFreeHandle(SQL_HANDLE_DBC, hdbc);
}
// Environment
if (henv != SQL_NULL_HENV)
SQLFreeHandle(SQL_HANDLE_ENV, henv);
return 0;
}
Further information
