Author: wyoung
Date: Tue Jul 17 20:12:29 2007
New Revision: 1713
URL: http://svn.gna.org/viewcvs/mysqlpp?rev=1713&view=rev
Log:
Simplified fieldinf example
Modified:
trunk/examples/fieldinf.cpp
Modified: trunk/examples/fieldinf.cpp
URL:
http://svn.gna.org/viewcvs/mysqlpp/trunk/examples/fieldinf.cpp?rev=1713&r1=1712&r2=1713&view=diff
==============================================================================
--- trunk/examples/fieldinf.cpp (original)
+++ trunk/examples/fieldinf.cpp Tue Jul 17 20:12:29 2007
@@ -1,12 +1,11 @@
/***********************************************************************
- fieldinf1.cpp - Example showing how to request information about the
- fields in a table, such as their SQL and C++-equivalent types, as
- MySQL++ sees it.
+ fieldinf.cpp - Shows how to request information about the fields in a
+ table, such as their SQL and C++-equivalent types.
- Copyright (c) 1998 by Kevin Atkinson, (c) 1999, 2000 and 2001 by
- MySQL AB, and (c) 2004-2007 by Educational Technology Resources, Inc.
- Others may also hold copyrights on code in this file. See the CREDITS
- file in the top directory of the distribution for details.
+ Copyright (c) 1998 by Kevin Atkinson, (c) 1999-2001 by MySQL AB, and
+ (c) 2004-2007 by Educational Technology Resources, Inc. Others may
+ also hold copyrights on code in this file. See the CREDITS file in
+ the top directory of the distribution for details.
This file is part of MySQL++.
@@ -28,83 +27,66 @@
#include "util.h"
-#include <mysql++.h>
-
#include <iostream>
#include <iomanip>
using namespace std;
-using namespace mysqlpp;
+
int
main(int argc, char *argv[])
{
try {
- Connection con(use_exceptions);
+ mysqlpp::Connection con;
if (!connect_to_db(argc, argv, con)) {
return 1;
}
- Query query = con.query("select * from stock");
- cout << "Query: " << query.preview() << endl;
+ mysqlpp::Query query = con.query("select * from stock");
+ mysqlpp::Result res = query.store();
- Result res = query.store();
- cout << "Records Found: " << res.size() << endl << endl;
+ char widths[] = { 8, 15, 20 };
+ cout.setf(ios::left);
+ cout << setw(widths[0]) << "Field" <<
+ setw(widths[1]) << "SQL Type" <<
+ setw(widths[2]) << "Mangled C++ Type" <<
+ endl;
+ for (int i = 0; i < sizeof(widths) / sizeof(widths[0]); ++i) {
+ cout << string(widths[i] - 1, '=') << ' ';
+ }
+ cout << endl;
+
+ for (size_t i = 0; i < res.names().size(); i++) {
+ cout << setw(widths[0]) << res.names(i).c_str() <<
+ setw(widths[1]) <<
res.types(i).sql_name() <<
+ setw(widths[2]) << res.types(i).name()
<<
+ endl;
+ }
+ cout << endl;
- cout << "Query Info:\n";
- cout.setf(ios::left);
-
- for (unsigned int i = 0; i < res.names().size(); i++) {
- cout << setw(2) << i
- // this is the name of the field
- << setw(15) << res.names(i).c_str()
- // this is the SQL identifier name
- // Result::types(unsigned int) returns
a mysql_type_info which in many
- // ways is like type_info except that
it has additional sql type
- // information in it. (with one of the
methods being sql_name())
- << setw(15) << res.types(i).sql_name()
- // this is the C++ identifier name
which most closely resembles
- // the sql name (its is implementation
defined and often not very readable)
- << setw(20) << res.types(i).name()
- << endl;
+ // Simple type check
+ if (res.types(0) == typeid(string)) {
+ cout << "SQL type of 'item' field most closely
resembles "
+ "the C++ string type." << endl;
}
- cout << endl;
-
- if (res.types(0) == typeid(string)) {
- // this is demonstrating how a mysql_type_info can be
- // compared with a C++ type_info.
- cout << "Field 'item' is of an SQL type which most "
- "closely resembles\nthe C++ string
type\n";
+ // Tricky type check: the 'if' path shouldn't happen because the
+ // num field has the NULL attribute. We need to dig a little
+ // deeper if we want to ignore this in our type checks.
+ if (res.types(1) == typeid(mysqlpp::longlong)) {
+ cout << "Should not happen! Type check failure." <<
endl;
}
-
- if (res.types(1) == typeid(longlong)) {
- cout << "Field 'num' is of an SQL type which most "
- "closely resembles\nC++ long long int
type\n";
- }
- else if (res.types(1).base_type() == typeid(longlong)) {
- // you have to be careful as if it can be null the
actual
- // type is Null<TYPE> not TYPE. So you should always
use
- // the base_type method to get at the underlying type.
- // If the type is not null than this base type would be
- // the same as its type.
- cout << "Field 'num' base type is of an SQL type which "
- "most closely\nresembles the C++ long
long int type\n";
+ else {
+ cout << "SQL type of 'num' field most closely resembles
"
+ "MySQL++'s longlong type." << endl;
}
}
- catch (const BadQuery& er) {
+ catch (const mysqlpp::BadQuery& er) {
// Handle any query errors
cerr << "Query error: " << er.what() << endl;
return -1;
}
- catch (const BadConversion& er) {
- // Handle bad conversions
- cerr << "Conversion error: " << er.what() << endl <<
- "\tretrieved data size: " << er.retrieved <<
- ", actual size: " << er.actual_size << endl;
- return -1;
- }
- catch (const Exception& er) {
+ catch (const mysqlpp::Exception& er) {
// Catch-all for any other MySQL++ exceptions
cerr << "Error: " << er.what() << endl;
return -1;
_______________________________________________
Mysqlpp-commits mailing list
[email protected]
https://mail.gna.org/listinfo/mysqlpp-commits
