/**********************************************************************
* FILENAME : CopyDescriptor.c
*
* DESCRIPTION :
* Example illustrates use of SQLCopyDesc to copy one table to another.
* This is done by copying the descriptors of a SELECT statement to the
* descriptors of an INSERT statement, with a loop which performs
* SELECT and INSERT for all the records.
*
* Basically the rows of the SELECT become the PARAMS of the INSERT
*
* ODBC USAGE :
* SQLAllocHandle to allocate two statement handles,
one a SELECT and one an INSERT
* SQLGetStmtAttr to obtain the ARD and IRD handles of the SELECT
* SQLGetStmtAttr to obtain the APD and IPD handles of the SELECT
* SQLSetStmtAttr with SQL_ATTR_ROW_BIND_TYPE to define ROW binding on
* the SELECT
* SQLSetStmtAttr with SQL_ATTR_ROW_ARRAY_SIZE to define the no of records
* on the SELECT
* SQLSetStmtAttr with SQL_ATTR_ROWS_FETCHED_PTR to define a variable into
* which the num of rows fetched are returned
* SQLExecDirect to execute a SELECT without need to be prepared
* SQLBindCol to bind the 4 columns in the SELECT
* SQLCopyDesc to copy the SELECT ARD descriptor to the INSERT APD
* descriptor
* SQLCopyDesc to copy the SELECT IRD descriptor to the INSERT IPD
* descriptor
* SQLSetStmtAttr to define the same status array for the
* SELECT and INSERT
* SQLSetDescField to set the parameter type to SQL_PARAM_INPUT on each
* of the fields for the INSERT
* SQLPrepare to prepare the INSERT
* SQLFetchScroll on the SELECT followed by SQLExecute on the INSERT and
* SQLFetch until SQL_NO_DATA returned
*
* The example (based on SQL SERVER) uses two active statements at the
* same time and needs the Mars_Connection setting in the odbc.ini file
* set to yes. This allowes Multiple Active Result Sets to work (for
* concurrent SELECTs and INSERTs). MARS was new in SQLServer 2005.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sql.h>
#include <sqlext.h>
#include <string.h>
#include "util.c"
#define ROWS 10
#define BOOKMARK_LEN 10
#define PERSONID_LEN 2
#define LASTNAME_LEN 255
#define FIRSTNAME_LEN 255
#define ADDRESS_LEN 255
#define CITY_LEN 255
SQLRETURN retcode;
// Person row (same as TestTBL1) minus PersonID identity field
typedef struct tagCustStruct {
SQLCHAR FirstName[255];
SQLLEN lenFirstName;
SQLCHAR LastName[255];
SQLLEN lenLastName;
SQLCHAR Address[255];
SQLLEN lenAddress;
SQLCHAR City[255];
SQLLEN lenCity;
} CustStruct;
int main () {
CustStruct CustArray[ROWS]; // rowset buffer
SQLUSMALLINT sts_ptr[ROWS]; // status pointer
SQLHDESC hArd0, hIrd0, hApd1, hIpd1;
SQLHENV henv = SQL_NULL_HENV; // Environment
SQLHDBC hdbc = SQL_NULL_HDBC; // Connection handle
SQLHSTMT hstmt0 = SQL_NULL_HSTMT; // Statement handle
SQLHSTMT hstmt1 = SQL_NULL_HSTMT; // Statement handle
SQLRETURN retcode;
SQLLEN RowsFetched = 0, params_processed = 0;
int i;
// Allocate Environment Handle
retcode = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &henv);
CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_ENV)",
henv, SQL_HANDLE_ENV);
// Set ODBC version
retcode = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION,
(SQLCHAR *)(void*)SQL_OV_ODBC3, -1);
CHECK_ERROR(retcode, "SQLSetEnvAttr(SQL_ATTR_ODBC_VERSION)",
henv, SQL_HANDLE_ENV);
// Allocate Connection Handle
retcode = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);
CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_DBC)",
hdbc, SQL_HANDLE_DBC);
// Set Login Timeout
retcode = SQLSetConnectAttr(hdbc, SQL_LOGIN_TIMEOUT, (SQLPOINTER)10, 0);
CHECK_ERROR(retcode, "SQLSetConnectAttr(SQL_LOGIN_TIMEOUT)",
hdbc, SQL_HANDLE_DBC);
// Connect to DSN
retcode = SQLConnect(hdbc, (SQLCHAR*) "DATASOURCE", SQL_NTS,
(SQLCHAR*) NULL, 0, NULL, 0);
CHECK_ERROR(retcode, "SQLConnect(DATASOURCE)",
hdbc, SQL_HANDLE_DBC);
// Allocate Statement 0 Handle (For Select)
retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt0);
CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_STMT0)",
hstmt0, SQL_HANDLE_STMT);
// Allocate Statement 1 Handle (For Insert)
retcode = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt1);
CHECK_ERROR(retcode, "SQLAllocHandle(SQL_HANDLE_STMT1)",
hstmt1, SQL_HANDLE_STMT);
// Get the ARD and IRD row descriptors for hstmt0
retcode = SQLGetStmtAttr(hstmt0, SQL_ATTR_APP_ROW_DESC, &hArd0, 0, NULL);
CHECK_ERROR(retcode, "SQLGetStmtAttr(SQL_ATTR_APP_ROW_DESC)",
hstmt0, SQL_HANDLE_STMT);
retcode = SQLGetStmtAttr(hstmt0, SQL_ATTR_IMP_ROW_DESC, &hIrd0, 0, NULL);
CHECK_ERROR(retcode, "SQLGetStmtAttr(SQL_ATTR_IMP_ROW_DESC)",
hstmt0, SQL_HANDLE_STMT);
// Get the APD and IPD param descriptors for hstmt1
retcode = SQLGetStmtAttr(hstmt1, SQL_ATTR_APP_PARAM_DESC, &hApd1, 0, NULL);
CHECK_ERROR(retcode, "SQLGetStmtAttr(SQL_ATTR_APP_PARAM_DESC)",
hstmt1, SQL_HANDLE_STMT);
retcode = SQLGetStmtAttr(hstmt1, SQL_ATTR_IMP_PARAM_DESC, &hIpd1, 0, NULL);
CHECK_ERROR(retcode, "SQLGetStmtAttr(SQL_ATTR_IMP_PARAM_DESC)",
hstmt1, SQL_HANDLE_STMT);
// Use row-wise binding on hstmt0 to fetch rows
retcode = SQLSetStmtAttr(hstmt0, SQL_ATTR_ROW_BIND_TYPE,
(SQLPOINTER) sizeof(CustStruct), 0);
CHECK_ERROR(retcode, "SQLSetStmtAttr(SQL_ATTR_ROW_BIND_TYPE)",
hstmt0, SQL_HANDLE_STMT);
// Set rowset size for hstmt0
retcode = SQLSetStmtAttr(hstmt0, SQL_ATTR_ROW_ARRAY_SIZE, (SQLPOINTER) ROWS, 0);
CHECK_ERROR(retcode, "SQLSetStmtAttr(SQL_ATTR_ROW_ARRAY_SIZE)",
hstmt0, SQL_HANDLE_STMT);
// Rows fetched
retcode = SQLSetStmtAttr(hstmt0, SQL_ATTR_ROWS_FETCHED_PTR, &RowsFetched,0);
CHECK_ERROR(retcode, "SQLSetStmtAttr(SQL_ATTR_ROWS_FETCHED_PTR)",
hstmt0, SQL_HANDLE_STMT);
// Execute a SELECT statement
retcode = SQLExecDirect(hstmt0,
"SELECT FirstName, LastName, Address, City FROM TestTBL1 order by FirstName", SQL_NTS);
CHECK_ERROR(retcode, "SQLExecDirect(SQL_HANDLE_STMT0)",
hstmt0, SQL_HANDLE_STMT);
// Bind columns for reading records
// Bind COL 1 - FirstName
retcode = SQLBindCol(hstmt0, 1, SQL_C_CHAR,
&CustArray[0].FirstName,
sizeof(CustArray[0].FirstName),
&CustArray[0].lenFirstName);
CHECK_ERROR(retcode, "SQLBindCol(1)",
hstmt0, SQL_HANDLE_STMT);
// Bind COL 2 - LastName
retcode = SQLBindCol(hstmt0, 2, SQL_C_CHAR,
&CustArray[0].LastName,
sizeof(CustArray[0].LastName),
&CustArray[0].lenLastName);
CHECK_ERROR(retcode, "SQLBindCol(2)",
hstmt0, SQL_HANDLE_STMT);
// Bind Col 3- Address
retcode = SQLBindCol(hstmt0, 3, SQL_C_CHAR,
&CustArray[0].Address,
sizeof(CustArray[0].Address),
&CustArray[0].lenAddress);
CHECK_ERROR(retcode, "SQLBindCol(3)",
hstmt0, SQL_HANDLE_STMT);
// Bind Col 4 - City
retcode = SQLBindCol(hstmt0, 4, SQL_C_CHAR,
&CustArray[0].City,
sizeof(CustArray[0].City),
&CustArray[0].lenCity);
CHECK_ERROR(retcode, "SQLBindCol(4)",
hstmt0, SQL_HANDLE_STMT);
// Perform parameter bindings on hstmt1.
// Copy SELECT ARD to INSERT APD (App RECORD descriptor
// becomes App PARAM descriptor)
retcode = SQLCopyDesc(hArd0, hApd1);
if ( (retcode != SQL_SUCCESS) &&
(retcode != SQL_SUCCESS_WITH_INFO) ) {
extract_error("SQLCopyDesc(hArd0, hApd1, 0)", hArd0,
SQL_HANDLE_DESC);
extract_error("SQLCopyDesc(hArd0, hApd1, 1)", hApd1,
SQL_HANDLE_DESC);
goto exit;
}
// Copy SELECT IRD to INSERT IPD
// (Imp RECORD descriptor becomes Imp PARAM descriptor)
retcode = SQLCopyDesc(hIrd0, hIpd1);
if ( (retcode != SQL_SUCCESS) &&
(retcode != SQL_SUCCESS_WITH_INFO) ) {
extract_error("SQLCopyDesc(hIrd0, hIpd1, 0)", hIrd0,
SQL_HANDLE_DESC);
extract_error("SQLCopyDesc(hIrd0, hIpd1, 1)", hIpd1,
SQL_HANDLE_DESC);
goto exit;
}
// Set the ARRAY_STATUS_PTR field of IRD (ROW STATUS Array for SELECT)
retcode = SQLSetStmtAttr(hstmt0, SQL_ATTR_ROW_STATUS_PTR, sts_ptr,
SQL_IS_POINTER);
CHECK_ERROR(retcode, "SQLSetStmtAttr(SQL_ATTR_ROW_STATUS_PTR)",
hstmt0, SQL_HANDLE_STMT);
// Set the ARRAY_STATUS_PTR field of APD to be the same as that in IRD
// (ROW STATUS Array for INSERT)
retcode = SQLSetStmtAttr(hstmt1, SQL_ATTR_PARAM_OPERATION_PTR, sts_ptr,
SQL_IS_POINTER);
CHECK_ERROR(retcode, "SQLSetStmtAttr(PARAM_OPERATION_PTR)",
hstmt1, SQL_HANDLE_STMT);
// Set the hIpd1 record input parameters
// Set Desc Field 1 as INPUT in INSERT IPD
retcode = SQLSetDescField(hIpd1, 1, SQL_DESC_PARAMETER_TYPE,
(SQLPOINTER)SQL_PARAM_INPUT, SQL_IS_INTEGER);
CHECK_ERROR(retcode, "SQLSetDescField(DESC_PARAMETER_TYPE 1)",
hstmt1, SQL_HANDLE_STMT);
// Set Desc Field 2 as INPUT in INSERT IPD
retcode = SQLSetDescField(hIpd1, 2, SQL_DESC_PARAMETER_TYPE,
(SQLPOINTER)SQL_PARAM_INPUT, SQL_IS_INTEGER);
CHECK_ERROR(retcode, "SQLSetDescField(DESC_PARAMETER_TYPE 2)",
hstmt1, SQL_HANDLE_STMT);
// Set Desc Field 3 as INPUT in INSERT IPD
retcode = SQLSetDescField(hIpd1, 3, SQL_DESC_PARAMETER_TYPE,
(SQLPOINTER)SQL_PARAM_INPUT, SQL_IS_INTEGER);
CHECK_ERROR(retcode, "SQLSetDescField(DESC_PARAMETER_TYPE 3)",
hstmt1, SQL_HANDLE_STMT);
// Set Desc Field 4 as INPUT in INSERT IPD
retcode = SQLSetDescField(hIpd1, 4, SQL_DESC_PARAMETER_TYPE,
(SQLPOINTER)SQL_PARAM_INPUT, SQL_IS_INTEGER);
CHECK_ERROR(retcode, "SQLSetDescField(DESC_PARAMETER_TYPE 4)",
hstmt1, SQL_HANDLE_STMT);
// Prepare an INSERT statement on hstmt1.
// TestTBL1Copy is a copy of TestTBL1
retcode = SQLPrepare(hstmt1, "INSERT INTO TestTBL1Copy (FirstName, LastName, Address, City) VALUES (?, ?, ?, ?)", SQL_NTS);
CHECK_ERROR(retcode, "SQLPrepare(hstmt1)",
hstmt1, SQL_HANDLE_STMT);
// In a loop, fetch a rowset, and copy the fetched rowset to TestTBL1Copy
// Fetch initial rowset from SELECT
retcode = SQLFetchScroll(hstmt0, SQL_FETCH_NEXT, 0);
// Loop while data and success
while (SQL_SUCCEEDED(retcode)) {
printf ("Rows Fetched : %i\n", (int) RowsFetched);
for (i=0;i<ROWS;i++) {
printf ("%i", sts_ptr[i]);
if (i!=ROWS-1)
printf (", ");
else
printf ("\n");
}
for (i=0;i<RowsFetched;i++) {
printf ("Record %i, Status %i, First Field - %.10s\n",
i+1, sts_ptr[i], CustArray[i].FirstName);
}
// The row status array (returned by the FetchScroll of hstmt0)
// is used as input status in the APD of hstmt1 and hence determines
// which elements of the rowset buffer are inserted.
// Execute INSERT
retcode = SQLExecute(hstmt1);
CHECK_ERROR(retcode, "SQLExecute(hstmt1)",
hstmt1, SQL_HANDLE_STMT);
printf ("SQLExecute(hstmt1) OK\n");
// Fetch Scroll next rowset from SELECT
retcode = SQLFetchScroll(hstmt0, SQL_FETCH_NEXT, 0);
if (retcode == SQL_NO_DATA) {
printf ("SQL_NO_DATA\n");
} else {
CHECK_ERROR(retcode, "SQLFetchScroll(SQL_HANDLE_STMT 0)",
hstmt0, SQL_HANDLE_STMT);
printf ("SQLFetchScroll(hstmt0) OK\n");
}
}
exit:
printf ("\nComplete.\n");
// Free handles
// Statement 0
if (hstmt0 != SQL_NULL_HSTMT)
SQLFreeHandle(SQL_HANDLE_STMT, hstmt0);
// Statement 1
if (hstmt1 != SQL_NULL_HSTMT)
SQLFreeHandle(SQL_HANDLE_STMT, hstmt1);
// 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;
}
See Also
