00001 // database query helper functions -*- C++ -*- 00002 // $Id: query.h,v 1.4 2004/03/11 10:05:18 roger Exp $ 00003 // 00004 // Copyright (C) 2003 Roger Leigh <rleigh@debian.org> 00005 // 00006 // 00007 // All rights reserved. 00008 // 00009 // Redistribution and use in source and binary forms, with or without 00010 // modification, are permitted provided that the following conditions 00011 // are met: 00012 // 00013 // * Redistributions of source code must retain the above copyright 00014 // notice, this list of conditions and the following disclaimer. 00015 // * Redistributions in binary form must reproduce the above 00016 // copyright notice, this list of conditions and the following 00017 // disclaimer in the documentation and/or other materials provided 00018 // with the distribution. 00019 // * Neither the name of the author, nor the names of other 00020 // contributors may be used to endorse or promote products derived 00021 // from this software without specific prior written permission. 00022 // 00023 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 00024 // CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 00025 // INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00026 // MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 00027 // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 00028 // BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00029 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00030 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 00031 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 00032 // ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR 00033 // TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 00034 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00035 // SUCH DAMAGE. 00036 // 00038 00039 #ifndef PQXX_OBJECT_QUERY_HELPERSH 00040 #define PQXX_OBJECT_QUERY_HELPERSH 00041 00042 #include <sstream> 00043 00044 namespace pqxxobject 00045 { 00051 template< typename T, template <typename> class F > 00052 struct query_helper 00053 { 00060 std::pair< std::string, std::string > 00061 apply(F<T>& field) 00062 { 00063 std::ostringstream value; 00064 value << field; 00065 return std::pair< std::string, std::string > 00066 (field.get_column_name(), value.str()); 00067 } 00068 }; 00069 00070 template< template <typename> class F > 00071 struct query_helper< std::string, F > 00072 { 00073 std::pair< std::string, std::string > 00074 apply(F<std::string>& field) 00075 { 00076 std::ostringstream value; 00077 value << pqxx::Quote(*field); 00078 return std::pair< std::string, std::string > 00079 (field.get_column_name(), value.str()); 00080 } 00081 }; 00082 00083 template< template <typename> class F > 00084 struct query_helper< bool, F > 00085 { 00086 std::pair< std::string, std::string > 00087 apply(F<bool>& field) 00088 { 00089 std::ostringstream value; 00090 value << (*field ? "true" : "false"); 00091 return std::pair< std::string, std::string > 00092 (field.get_column_name(), value.str()); 00093 } 00094 }; 00095 00096 }; // namespace pqxxobject 00097 00098 #endif // PQXX_OBJECT_QUERY_HELPERSH