added: TextStream a class similar to std::ostringstream

but with a Clear() method
       the dynamic allocated buffer can be easily reused
added: DbTextStream a special version of a stream
       used to create a database string query
       everything is escaped by default
added: DbBase a base class with some basic methods for communicating
       with the database
added: DbConn a class for managing connection to the database
changed: some refactoring in Db class       



git-svn-id: svn://ttmath.org/publicrep/winix/trunk@655 e52654a7-88a9-db11-a3e9-0013d4bc506e

db/dbtextstream.h

@@ -0,0 +1,144 @@
+/*
+ * This file is a part of Winix
+ * and is not publicly distributed
+ * 
+ * Copyright (c) 2010, Tomasz Sowa
+ * All rights reserved.
+ * 
+ */
+ 
+#ifndef headerfile_winix_core_dbtextstream
+#define headerfile_winix_core_dbtextstream
+
+#include "core/textstream.h"
+
+
+
+/*
+	DbTextStream is used as a buffer for creating a database's query
+	By default all operators<< espace its string artuments. If you don't want
+	to escape an argument you should use a helper function R() (raw argument)
+	note: you have to define the function yourself, we do not provide it
+	because such a short name would make a mess in namespaces
+
+	sample:
+	create a helper function R as follows:
+
+		template<class RawType>
+		DbTextStream::RawText<RawType> R(const RawType & par)
+		{
+			return DbTextStream::RawText<RawType>(par);
+		}
+	
+	now you can use DbTextStream in an easy way:
+
+		DbTextStream query;
+		std::string key = "some string";
+		query << R("select * from table where key=") << key << R(";");
+
+	in above example only the key is escaped.
+
+	Also with escaping operators<< insert commas between parameters, e.g.:
+		
+		query << R("insert into table (key1, key2, key3) values (")
+			  << key1
+			  << key2
+			  << key3
+			  << R(");");
+
+	between key1 key2 and key3 are commas inserted automatically
+*/
+class DbTextStream : public TextStream
+{
+public:
+
+
+	/*
+		a helper struct to select a proper operator<<
+		(for non-escaping versions of these operators)
+	*/
+	template<class RawType>
+	struct RawText
+	{
+		const RawType & par;
+
+		RawText(const RawText<RawType> & p) : par(p.par) {}
+		RawText(const RawType & p) : par(p) {}
+	};
+
+
+	DbTextStream();
+
+	// extented escaping: adding E character before the first quote e.g. E'string'
+	// default: true
+	void SetExtented(bool ext);
+
+
+
+	/*
+		without escaping
+	*/
+
+	DbTextStream & PutText(const char *);
+	DbTextStream & PutText(const std::string *);
+	DbTextStream & PutText(const std::string &);
+
+	/*
+		we need this template operator for such calling:
+		dbtextstream_object << R("some string");
+		"some string" is actually a table (not a pointer)
+	*/
+	template<size_t str_size>
+	DbTextStream & operator<<(const RawText<char [str_size]> & raw)	{ return PutText(raw.par); }
+
+	DbTextStream & operator<<(const RawText<const char*> & raw);
+	DbTextStream & operator<<(RawText<std::string> raw);
+	DbTextStream & operator<<(RawText<char> raw);
+	DbTextStream & operator<<(RawText<int> raw);
+	DbTextStream & operator<<(RawText<long> raw);
+	DbTextStream & operator<<(RawText<unsigned int> raw);
+	DbTextStream & operator<<(RawText<unsigned long> raw);
+	DbTextStream & operator<<(RawText<double> raw);
+	DbTextStream & operator<<(RawText<void*> raw);
+
+
+
+	/*
+		with escaping
+	*/
+
+	DbTextStream & EBinPutChar(char c);
+	DbTextStream & ETextPutChar(char c);
+
+	DbTextStream & EPutText(const char * str);
+	DbTextStream & EPutText(const std::string * str);
+	DbTextStream & EPutText(const std::string & str);
+
+	DbTextStream & EPutBin(const char * str, size_t len);
+	DbTextStream & EPutBin(const std::string * str); 
+	DbTextStream & EPutBin(const std::string & str); 
+
+	DbTextStream & operator<<(const char * str);
+	DbTextStream & operator<<(const std::string * str);
+	DbTextStream & operator<<(const std::string & str);
+	DbTextStream & operator<<(char);
+	DbTextStream & operator<<(int);
+	DbTextStream & operator<<(long);
+	DbTextStream & operator<<(unsigned int);
+	DbTextStream & operator<<(unsigned long);
+	DbTextStream & operator<<(double);
+	DbTextStream & operator<<(const void *);
+
+
+private:
+
+	bool was_param;
+	bool ext_escape;
+
+};
+
+
+
+
+#endif
+