execute.c

关系型数据库 Postgresql 6.5.2

//      -       -       -       -       -       -       -       -       -

RETCODE SQL_API SQLCancel(
        HSTMT   hstmt)  // Statement to cancel.
{
static char *func="SQLCancel";
StatementClass *stmt = (StatementClass *) hstmt;
RETCODE result;
#ifdef WIN32
HMODULE hmodule;
FARPROC addr;
#endif

	mylog( "%s: entering...\n", func);

	//	Check if this can handle canceling in the middle of a SQLPutData?
	if ( ! stmt) {
		SC_log_error(func, "", NULL);
		return SQL_INVALID_HANDLE;
	}

	//	Not in the middle of SQLParamData/SQLPutData so cancel like a close.
	if (stmt->data_at_exec < 0) {


		/*	MAJOR HACK for Windows to reset the driver manager's cursor state:
			Because of what seems like a bug in the Odbc driver manager,
			SQLCancel does not act like a SQLFreeStmt(CLOSE), as many
			applications depend on this behavior.  So, this 
			brute force method calls the driver manager's function on
			behalf of the application.  
		*/

#ifdef WIN32
		if (globals.cancel_as_freestmt) {
			hmodule = GetModuleHandle("ODBC32");
			addr = GetProcAddress(hmodule, "SQLFreeStmt");
			result = addr( (char *) (stmt->phstmt) - 96, SQL_CLOSE);
		}
		else {
			result = SQLFreeStmt( hstmt, SQL_CLOSE);
		}
#else
		result = SQLFreeStmt( hstmt, SQL_CLOSE);
#endif

		mylog("SQLCancel:  SQLFreeStmt returned %d\n", result);

		SC_clear_error(hstmt);
		return SQL_SUCCESS;
	}

	//	In the middle of SQLParamData/SQLPutData, so cancel that.
	//	Note, any previous data-at-exec buffers will be freed in the recycle
	//	if they call SQLExecDirect or SQLExecute again.

	stmt->data_at_exec = -1;
	stmt->current_exec_param = -1;
	stmt->put_data = FALSE;

	return SQL_SUCCESS;

}

//      -       -       -       -       -       -       -       -       -

//      Returns the SQL string as modified by the driver.
//		Currently, just copy the input string without modification
//		observing buffer limits and truncation.
RETCODE SQL_API SQLNativeSql(
        HDBC      hdbc,
        UCHAR FAR *szSqlStrIn,
        SDWORD     cbSqlStrIn,
        UCHAR FAR *szSqlStr,
        SDWORD     cbSqlStrMax,
        SDWORD FAR *pcbSqlStr)
{
static char *func="SQLNativeSql";
int len = 0;
char *ptr;
ConnectionClass *conn = (ConnectionClass *) hdbc;
RETCODE result;

	mylog( "%s: entering...cbSqlStrIn=%d\n", func, cbSqlStrIn);

	ptr = (cbSqlStrIn == 0) ? "" : make_string(szSqlStrIn, cbSqlStrIn, NULL);
	if ( ! ptr) {
		conn->errornumber = CONN_NO_MEMORY_ERROR;
		conn->errormsg = "No memory available to store native sql string";
		CC_log_error(func, "", conn);
		return SQL_ERROR;
	}

	result = SQL_SUCCESS;
	len = strlen(ptr);

	if (szSqlStr) {
		strncpy_null(szSqlStr, ptr, cbSqlStrMax);

		if (len >= cbSqlStrMax)  {
			result = SQL_SUCCESS_WITH_INFO;
			conn->errornumber = STMT_TRUNCATED;
			conn->errormsg = "The buffer was too small for the result.";
		}
	}

	if (pcbSqlStr)
		*pcbSqlStr = len;

	free(ptr);

    return result;
}

//      -       -       -       -       -       -       -       -       -

//      Supplies parameter data at execution time.      Used in conjuction with
//      SQLPutData.

RETCODE SQL_API SQLParamData(
        HSTMT   hstmt,
        PTR FAR *prgbValue)
{
static char *func = "SQLParamData";
StatementClass *stmt = (StatementClass *) hstmt;
int i, retval;

	mylog( "%s: entering...\n", func);

	if ( ! stmt) {
		SC_log_error(func, "", NULL);
		return SQL_INVALID_HANDLE;
	}

	mylog("%s: data_at_exec=%d, params_alloc=%d\n", func, stmt->data_at_exec, stmt->parameters_allocated);

	if (stmt->data_at_exec < 0) {
		stmt->errornumber = STMT_SEQUENCE_ERROR;
		stmt->errormsg = "No execution-time parameters for this statement";
		SC_log_error(func, "", stmt);
		return SQL_ERROR;
	}

	if (stmt->data_at_exec > stmt->parameters_allocated) {
		stmt->errornumber = STMT_SEQUENCE_ERROR;
		stmt->errormsg = "Too many execution-time parameters were present";
		SC_log_error(func, "", stmt);
		return SQL_ERROR;
	}

	/* close the large object */
	if ( stmt->lobj_fd >= 0) {
		lo_close(stmt->hdbc, stmt->lobj_fd);
		stmt->lobj_fd = -1;
	}


	/*	Done, now copy the params and then execute the statement */
	if (stmt->data_at_exec == 0) {
		retval = copy_statement_with_parameters(stmt);
		if (retval != SQL_SUCCESS)
			return retval;

		stmt->current_exec_param = -1;

		return SC_execute(stmt);
	}

	/*	Set beginning param;  if first time SQLParamData is called , start at 0.
		Otherwise, start at the last parameter + 1.
	*/
	i = stmt->current_exec_param >= 0 ? stmt->current_exec_param+1 : 0;

	/*	At least 1 data at execution parameter, so Fill in the token value */
	for ( ; i < stmt->parameters_allocated; i++) {
		if (stmt->parameters[i].data_at_exec == TRUE) {
			stmt->data_at_exec--;
			stmt->current_exec_param = i;
			stmt->put_data = FALSE;
			*prgbValue = stmt->parameters[i].buffer;	/* token */
			break;
		}
	}

	return SQL_NEED_DATA;
}

//      -       -       -       -       -       -       -       -       -

//      Supplies parameter data at execution time.      Used in conjunction with
//      SQLParamData.

RETCODE SQL_API SQLPutData(
        HSTMT   hstmt,
        PTR     rgbValue,
        SDWORD  cbValue)
{
static char *func = "SQLPutData";
StatementClass *stmt = (StatementClass *) hstmt;
int old_pos, retval;
ParameterInfoClass *current_param;
char *buffer;

	mylog( "%s: entering...\n", func);

	if ( ! stmt) {
		SC_log_error(func, "", NULL);
		return SQL_INVALID_HANDLE;
	}

	
	if (stmt->current_exec_param < 0) {
		stmt->errornumber = STMT_SEQUENCE_ERROR;
		stmt->errormsg = "Previous call was not SQLPutData or SQLParamData";
		SC_log_error(func, "", stmt);
		return SQL_ERROR;
	}

	current_param = &(stmt->parameters[stmt->current_exec_param]);

	if ( ! stmt->put_data) {	/* first call */

		mylog("SQLPutData: (1) cbValue = %d\n", cbValue);

		stmt->put_data = TRUE;

		current_param->EXEC_used = (SDWORD *) malloc(sizeof(SDWORD));
		if ( ! current_param->EXEC_used) {
			stmt->errornumber = STMT_NO_MEMORY_ERROR;
			stmt->errormsg = "Out of memory in SQLPutData (1)";
			SC_log_error(func, "", stmt);
			return SQL_ERROR;
		}

		*current_param->EXEC_used = cbValue;

		if (cbValue == SQL_NULL_DATA)
			return SQL_SUCCESS;


		/*	Handle Long Var Binary with Large Objects */
		if ( current_param->SQLType == SQL_LONGVARBINARY) {

			/*	store the oid */
			current_param->lobj_oid = lo_creat(stmt->hdbc, INV_READ | INV_WRITE);
			if (current_param->lobj_oid == 0) {
				stmt->errornumber = STMT_EXEC_ERROR;
				stmt->errormsg = "Couldnt create large object.";
				SC_log_error(func, "", stmt);
				return SQL_ERROR;
			}

			/*	major hack -- to allow convert to see somethings there */
			/*					have to modify convert to handle this better */
			current_param->EXEC_buffer = (char *) &current_param->lobj_oid;

			/*	store the fd */
			stmt->lobj_fd = lo_open(stmt->hdbc, current_param->lobj_oid, INV_WRITE);
			if ( stmt->lobj_fd < 0) {
				stmt->errornumber = STMT_EXEC_ERROR;
				stmt->errormsg = "Couldnt open large object for writing.";
				SC_log_error(func, "", stmt);
				return SQL_ERROR;
			}

			retval = lo_write(stmt->hdbc, stmt->lobj_fd, rgbValue, cbValue);
			mylog("lo_write: cbValue=%d, wrote %d bytes\n", cbValue, retval);

		}
		else {	/* for handling text fields and small binaries */

			if (cbValue == SQL_NTS) {
				current_param->EXEC_buffer = strdup(rgbValue);
				if ( ! current_param->EXEC_buffer) {
					stmt->errornumber = STMT_NO_MEMORY_ERROR;
					stmt->errormsg = "Out of memory in SQLPutData (2)";
					SC_log_error(func, "", stmt);
					return SQL_ERROR;
				}
			}
			else {
				current_param->EXEC_buffer = malloc(cbValue + 1);
				if ( ! current_param->EXEC_buffer) {
					stmt->errornumber = STMT_NO_MEMORY_ERROR;
					stmt->errormsg = "Out of memory in SQLPutData (2)";
					SC_log_error(func, "", stmt);
					return SQL_ERROR;
				}
				memcpy(current_param->EXEC_buffer, rgbValue, cbValue);
				current_param->EXEC_buffer[cbValue] = '\0';
			}
		}
	}

	else {	/* calling SQLPutData more than once */

		mylog("SQLPutData: (>1) cbValue = %d\n", cbValue);

		if (current_param->SQLType == SQL_LONGVARBINARY) {

			/* the large object fd is in EXEC_buffer */
			retval = lo_write(stmt->hdbc, stmt->lobj_fd, rgbValue, cbValue);
			mylog("lo_write(2): cbValue = %d, wrote %d bytes\n", cbValue, retval);

			*current_param->EXEC_used += cbValue;

		} else {

			buffer = current_param->EXEC_buffer;

			if (cbValue == SQL_NTS) {
				buffer = realloc(buffer, strlen(buffer) + strlen(rgbValue) + 1);
				if ( ! buffer) {
					stmt->errornumber = STMT_NO_MEMORY_ERROR;
					stmt->errormsg = "Out of memory in SQLPutData (3)";
					SC_log_error(func, "", stmt);
					return SQL_ERROR;
				}
				strcat(buffer, rgbValue);

				mylog("       cbValue = SQL_NTS: strlen(buffer) = %d\n", strlen(buffer));

				*current_param->EXEC_used = cbValue;

				/*	reassign buffer incase realloc moved it */
				current_param->EXEC_buffer = buffer;

			}
			else if (cbValue > 0) {

				old_pos = *current_param->EXEC_used;

				*current_param->EXEC_used += cbValue;

				mylog("        cbValue = %d, old_pos = %d, *used = %d\n", cbValue, old_pos, *current_param->EXEC_used);

				/* dont lose the old pointer in case out of memory */
				buffer = realloc(current_param->EXEC_buffer, *current_param->EXEC_used + 1);
				if ( ! buffer) {
					stmt->errornumber = STMT_NO_MEMORY_ERROR;
					stmt->errormsg = "Out of memory in SQLPutData (3)";
					SC_log_error(func, "", stmt);
					return SQL_ERROR;
				}

				memcpy(&buffer[old_pos], rgbValue, cbValue);
				buffer[*current_param->EXEC_used] = '\0';

				/*	reassign buffer incase realloc moved it */
				current_param->EXEC_buffer = buffer;
				
			}
			else {
				SC_log_error(func, "bad cbValue", stmt);
				return SQL_ERROR;
			}

		}
	}


	return SQL_SUCCESS;
}