--- sql/sqlite/parser3sqlite.C	2007/02/19 10:54:36	1.1
+++ sql/sqlite/parser3sqlite.C	2021/11/08 09:03:09	1.20
@@ -3,12 +3,12 @@
 
 	(c) Dmitry "Creator" Bobrik, 2004
 */
-//static const char *RCSId="$Id: parser3sqlite.C,v 1.1 2007/02/19 10:54:36 misha Exp $"; 
 
 #include "config_includes.h"
 
 #include "pa_sql_driver.h"
-//#include "windows.h"  // for messagebox
+
+volatile const char * IDENT_PARSER3SQLITE_C="$Id: parser3sqlite.C,v 1.20 2021/11/08 09:03:09 moko Exp $" IDENT_PA_SQL_DRIVER_H;
 
 #define NO_CLIENT_LONG_LONG
 #include "sqlite3.h"
@@ -17,31 +17,30 @@
 #define MAX_STRING 0x400
 #define MAX_NUMBER 20
 
+#define SQLITE_DEFAULT_CHARSET "UTF-8"
+#define PA_REGEXP
+
 #if _MSC_VER
 #	define snprintf _snprintf
 #	define strcasecmp _stricmp
 #endif
 
-static void MBox(const char *message, const char *title){
-//	MessageBox(0, (LPCSTR)message, (LPCSTR)title, MB_OK);
-}
-
 static char *lsplit(char *string, char delim) {
-    if(string) {
+	if(string) {
 		char *v=strchr(string, delim);
 		if(v) {
 			*v=0;
 			return v+1;
 		}
-    }
-    return 0;
+	}
+	return 0;
 }
 
 static char *lsplit(char **string_ref, char delim) {
-    char *result=*string_ref;
+	char *result=*string_ref;
 	char *next=lsplit(*string_ref, delim);
-    *string_ref=next;
-    return result;
+	*string_ref=next;
+	return result;
 }
 
 static void toupper_str(char *out, const char *in, size_t size) {
@@ -53,10 +52,95 @@ struct Connection {
 	SQL_Driver_services* services;
 
 	sqlite3* handle;
-	const char* cstrClientCharset;
+	const char* client_charset;
+	bool multi_statements;
 	bool autocommit;
+	int busy_timeout;
 };
 
+// sqlite client library funcs
+
+typedef int (*t_sqlite3_open)(const char *filename, sqlite3 **ppDb); t_sqlite3_open pa_sqlite3_open;
+
+typedef int (*t_sqlite3_close)(sqlite3 *); t_sqlite3_close pa_sqlite3_close;
+
+typedef int (*t_sqlite3_busy_timeout)(sqlite3*, int ms); t_sqlite3_busy_timeout pa_sqlite3_busy_timeout;
+
+typedef int (*t_sqlite3_exec)(sqlite3*, const char *sql, sqlite3_callback, void *, char **errmsg); t_sqlite3_exec pa_sqlite3_exec;
+
+typedef void (*t_sqlite3_free)(char *z); t_sqlite3_free pa_sqlite3_free;
+
+typedef const char *(* t_sqlite3_errmsg)(sqlite3*); t_sqlite3_errmsg pa_sqlite3_errmsg;
+
+typedef int (* t_sqlite3_prepare)(sqlite3 *db, const char *zSql, int nBytes, sqlite3_stmt **ppStmt, const char **pzTail); t_sqlite3_prepare pa_sqlite3_prepare;
+
+typedef int (* t_sqlite3_column_count)(sqlite3_stmt *pStmt); t_sqlite3_column_count pa_sqlite3_column_count;
+
+typedef int (* t_sqlite3_finalize)(sqlite3_stmt *pStmt); t_sqlite3_finalize pa_sqlite3_finalize;
+
+typedef const char *(* t_sqlite3_column_name)(sqlite3_stmt*,int); t_sqlite3_column_name pa_sqlite3_column_name;
+
+typedef int (* t_sqlite3_step)(sqlite3_stmt*); t_sqlite3_step pa_sqlite3_step;
+
+typedef int (* t_sqlite3_column_type)(sqlite3_stmt*, int iCol); t_sqlite3_column_type pa_sqlite3_column_type;
+
+typedef const unsigned char *(* t_sqlite3_column_text)(sqlite3_stmt*, int iCol); t_sqlite3_column_text pa_sqlite3_column_text;
+
+typedef const unsigned char *(* t_sqlite3_column_blob)(sqlite3_stmt*, int iCol); t_sqlite3_column_blob pa_sqlite3_column_blob;
+
+typedef int (* t_sqlite3_column_bytes)(sqlite3_stmt*, int iCol); t_sqlite3_column_bytes pa_sqlite3_column_bytes;
+
+#ifdef PA_REGEXP
+typedef int (* t_sqlite3_create_function)(sqlite3 *, const char *, int, int, void *, void (*)(sqlite3_context*,int,sqlite3_value**), void *, void *);  t_sqlite3_create_function pa_sqlite3_create_function;
+
+typedef const unsigned char *(* t_sqlite3_value_text)(sqlite3_value*); static t_sqlite3_value_text pa_sqlite3_value_text;
+
+typedef void *(* t_sqlite3_get_auxdata)(sqlite3_context*, int N); static t_sqlite3_get_auxdata pa_sqlite3_get_auxdata;
+
+typedef void (* t_sqlite3_set_auxdata)(sqlite3_context*, int N, void*, void (*)(void*)); static t_sqlite3_set_auxdata pa_sqlite3_set_auxdata;
+
+typedef void (* t_sqlite3_result_error)(sqlite3_context*, const char*, int); static t_sqlite3_result_error pa_sqlite3_result_error;
+
+typedef void (* t_sqlite3_result_error_nomem)(sqlite3_context*); static t_sqlite3_result_error_nomem pa_sqlite3_result_error_nomem;
+
+typedef void (* t_sqlite3_result_int)(sqlite3_context*, int); static t_sqlite3_result_int pa_sqlite3_result_int;
+
+
+// "regexp.h" hardcoded
+struct ReCompiled;
+const char *pa_re_compile(ReCompiled **ppRe, const char *zIn, int noCase);
+void pa_re_free(ReCompiled *pRe);
+int pa_re_match(ReCompiled *pRe, const unsigned char *zIn, int nIn);
+
+// regexp(pattern, string) sqlite3 function implementation
+static void regexp_sql_func(sqlite3_context *context, int argc, sqlite3_value **argv){
+	ReCompiled *pRe = (ReCompiled *)pa_sqlite3_get_auxdata(context, 0);
+	int setAux = 0; /* True to invoke sqlite3_set_auxdata() */
+
+	if( pRe==0 ){
+		const char *zPattern = (const char*)pa_sqlite3_value_text(argv[0]);
+		if( zPattern==0 ) return;
+		const char *zErr = pa_re_compile(&pRe, zPattern, 0);
+		if( zErr ){
+			pa_re_free(pRe);
+			pa_sqlite3_result_error(context, zErr, -1);
+			return;
+		}
+		if( pRe==0 ){
+			pa_sqlite3_result_error_nomem(context);
+			return;
+		}
+		setAux = 1;
+	}
+	const unsigned char *zStr = (const unsigned char*)pa_sqlite3_value_text(argv[1]);
+	if( zStr!=0 ){
+		pa_sqlite3_result_int(context, pa_re_match(pRe, zStr, -1));
+	}
+	if( setAux ){
+		pa_sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))pa_re_free);
+	}
+}
+#endif
 
 
 /**
@@ -70,284 +154,384 @@ public:
 
 	/// get api version
 	int api_version() { return SQL_DRIVER_API_VERSION; }
+
 	/// initialize driver by loading sql dynamic link library
 	const char *initialize(char *dlopen_file_spec) {
-		return dlopen_file_spec?
-			dlink(dlopen_file_spec):"client library column is empty";
+		return dlopen_file_spec ? dlink(dlopen_file_spec) : "client library column is empty";
 	}
+
 	/**	connect
 		@param url
-			format: @b database
-			SQLite options - database file name
+			format: @b db-file|:memory:|temporary:?
+			autocommit=1&			// =0 disable autocommit. in this case 1 connect == 1 transaction.
+									//	or you can use begin/commit|rollback explicitly
+			multi_statements=0&		// =1 allow many statements in 1 query
+			ClientCharset=UTF-8		// will transcode to/from specified charset instead of UTF-8 (default for sqlite)
 	*/
 	void connect(
-		char *url, 
-		SQL_Driver_services& services, 
-		void **connection_ref ///< output: Connection*
-		) {
-
-		int rc;
+				char *url, 
+				SQL_Driver_services& services, 
+				void **connection_ref ///< output: Connection*
+		){
 
-//		char *cstrBackwardCompAskServerToTranscode=0;
-
-		Connection& connection=*(Connection  *)services.malloc(sizeof(Connection));
+		Connection& connection=*(Connection *)services.malloc(sizeof(Connection));
+		*connection_ref=&connection;
 		connection.services=&services;
 
-		rc = sqlite3_open(url, &connection.handle);
-
-		if( SQLITE_OK != rc ){
-			services._throw(sqlite3_errmsg(connection.handle));
-			sqlite3_close(connection.handle);
+		connection.client_charset=SQLITE_DEFAULT_CHARSET;
+		connection.multi_statements=false;
+		connection.autocommit=true;
+		connection.busy_timeout=4000;
+
+		char* db_path=0;
+		char* db=url;
+		char* options=lsplit(db, '?');
+
+		if(strcmp(db, ":memory:")==0){ // in-memory temporary DB
+			db_path=db;
+		} else if(strcmp(db, ":temporary:")==0){ // on-disk temporary DB
+			// do nothing: empty path mean temporary table on disk
+		} else {
+			char* document_root=(char*)services.request_document_root();
+			if(!document_root) // path to DB-file which was specified by user is path from document_root as anywhere in parser
+				services._throw("document_root is empty");
+
+			db_path=(char*)services.malloc_atomic(strlen(document_root)+1+strlen(db)+1);
+			strcpy(db_path, document_root);
+			strcat(db_path, "/");
+			strcat(db_path, db);
 		}
 
-		connection.cstrClientCharset=0;	
-		connection.autocommit=true;   // значит что все INSERTы и UPDATEы коммитятся автоматически будучи запущенными отдельным запросом
-		*connection_ref=&connection;
-
-	}
-
-	void exec(Connection& connection, const char* statement) {
+		//services._throw(db_path);
 
-		char *zErr;
-		int rc;
-
-		rc = sqlite3_exec(connection.handle, statement, 0, 0, &zErr);
+		while(options){
+			if(char* key=lsplit(&options, '&')){
+				if(*key) {
+					if(char* value=lsplit(key, '=')){
+						if(strcasecmp(key, "multi_statements")==0){
+							if(atoi(value)!=0)
+								connection.multi_statements=true;
+						} else if(strcasecmp(key, "busy_timeout")==0){
+							connection.busy_timeout=atoi(value);
+						} else if(strcasecmp(key, "autocommit")==0){
+							if(atoi(value)==0)
+								connection.autocommit=false;
+						} else if(strcmp(key, "ClientCharset")==0){
+							toupper_str(value, value, strlen(value));
+							connection.client_charset=value;
+						} else
+							services._throw("unknown connect option" /*key*/);
+					} else 
+						services._throw("connect option without =value" /*key*/);
+				}
+			}
+		}
 
-		MBox(statement, "exec_stat");
+		// transcode database_name from $request:charset to UTF-8
+		if(db_path && _transcode_required(connection, SQLITE_DEFAULT_CHARSET)){
+			size_t length=strlen(db_path);
+			services.transcode((const char*)db_path, length,
+				(const char*&)db_path, length,
+				services.request_charset(),
+				SQLITE_DEFAULT_CHARSET);
 
-		if( SQLITE_OK!=rc ){
-			MBox(zErr, "exec_error");
-			connection.services->_throw(zErr);
-			sqlite3_free(zErr);
 		}
+		
 
+		int rc=pa_sqlite3_open(db_path, &connection.handle);
+#ifdef PA_REGEXP
+		if(rc==SQLITE_OK)
+			rc=pa_sqlite3_create_function(connection.handle, "regexp", 2, SQLITE_UTF8, 0, regexp_sql_func, 0, 0);
+#endif
+		if(rc!=SQLITE_OK){
+			const char* error_msg=pa_sqlite3_errmsg(connection.handle);
+			pa_sqlite3_close(connection.handle);
+			_throw(connection, error_msg);
+		}
+		
+		pa_sqlite3_busy_timeout(connection.handle, connection.busy_timeout);
+		
+		_begin_transaction(connection);
 	}
 
-	void disconnect(void *aconnection) {
+	void disconnect(void *aconnection){
 		Connection& connection=*static_cast<Connection*>(aconnection);
-
-		sqlite3_close(connection.handle);
+		pa_sqlite3_close(connection.handle);
 		connection.handle=0;
-
-		MBox("disconnect", "disconnect");
-
 	}
-	void commit(void *aconnection) {
-		//_asm int 3;
-		Connection& connection=*static_cast<Connection*>(aconnection);
-		MBox("commit", "commit");
 
+	void commit(void *aconnection){
+		Connection& connection=*static_cast<Connection*>(aconnection);
 		if(!connection.autocommit)
-			exec(connection, "commit");
+			_execute_cmd(connection, "COMMIT");
+
+		_begin_transaction(connection);
 	}
-	void rollback(void *aconnection) {
+
+	void rollback(void *aconnection){
 		Connection& connection=*static_cast<Connection*>(aconnection);
+		if(!connection.autocommit)
+			_execute_cmd(connection, "ROLLBACK");
 
-		MBox("rollback", "rollback");
+		_begin_transaction(connection);
+	}
 
-		if(!connection.autocommit)
-			exec(connection, "rollback");
+	bool ping(void *aconnection){
+		return true; // not needed
 	}
 
-	bool ping(void *aconnection) {
-		Connection& connection=*static_cast<Connection*>(aconnection);
+	// charset here is services.request_charset(), not connection.client_charset
+	// thus we can't use the sql server quoting support
+	const char* quote(void *aconnection, const char *str, unsigned int length) 
+	{
+		const char* from;
+		const char* from_end=str+length;
 
-		return true;  // пинг не требуется, т.к. сервер не сокетный :)
-	}
+		size_t quoted=0;
+
+		for(from=str; from<from_end; from++){
+			if(*from=='\'')
+				quoted++;
+		}
+
+		if(!quoted)
+			return str;
 
-	const char* quote(void *aconnection, const char *from, unsigned int length) {
 		Connection& connection=*static_cast<Connection*>(aconnection);
-		/*
-			3.23.22b
-			You must allocate the to buffer to be at least length*2+1 bytes long. 
-			(In the worse case, each character may need to be encoded as using two bytes, 
-			and you need room for the terminating null byte.)
-		*/
-		char *result=(char*)connection.services->malloc_atomic(length*2+1);
-		MBox(from, "quote");
-		char *to=result;
-		while(length--) {
-			if(*from=='\'') { // ' -> ''
-				*to++='\'';
-			}
-			*to++=*from++;
+		char *result=(char*)connection.services->malloc_atomic(length + quoted + 1);
+		char *to = result;
+
+		for(from=str; from<from_end; from++){
+			if(*from=='\'')
+				*to++= '\''; // ' -> ''
+			*to++=*from;
 		}
+		
 		*to=0;
-//		mysql_escape_string(result, from, length);
 		return result;
 	}
+
 	void query(void *aconnection, 
-		const char *astatement, 
-		size_t placeholders_count, Placeholder* placeholders, 
-		unsigned long offset, unsigned long limit,
-		SQL_Driver_query_event_handlers& handlers) {
+			const char *astatement, 
+			size_t placeholders_count, Placeholder* placeholders, 
+			unsigned long offset, unsigned long limit,
+			SQL_Driver_query_event_handlers& handlers
+		){
 
 		Connection& connection=*static_cast<Connection*>(aconnection);
 		SQL_Driver_services& services=*connection.services;
-		const char* cstrClientCharset=connection.cstrClientCharset;
 
 		if(placeholders_count>0)
-			services._throw("bind variables not supported (yet)");
-
+			services._throw("bind variables not supported yet");
+		
+		const char* request_charset=services.request_charset();
+		const char* client_charset=connection.client_charset;
+		bool transcode_needed=_transcode_required(connection);
+
+		// transcode query from $request:charset to ?ClientCharset
+		if(transcode_needed){
+			size_t length=strlen(astatement);
+			services.transcode(astatement, length,
+				astatement, length,
+				request_charset,
+				client_charset);
+		}
+		
 		const char *statement;
-		// вот этот блок добавляет в запрос LIMIT N, M если задано. SQLite поддерживает эти параметры
-		if(offset || limit) {
+		if(offset || limit!=SQL_NO_LIMIT){
 			size_t statement_size=strlen(astatement);
 			char *statement_limited=(char *)services.malloc_atomic(
-				statement_size+MAX_NUMBER*2+8/* limit #,#*/+1);
+				statement_size+MAX_NUMBER*2+8/* LIMIT #,#*/+1);
 			char *cur=statement_limited;
-			memcpy(cur, astatement, statement_size); cur+=statement_size;
-			cur+=sprintf(cur, " limit ");
+			memcpy(cur, astatement, statement_size);
+			cur+=statement_size;
+			cur+=sprintf(cur, " LIMIT ");
 			if(offset)
-				cur+=snprintf(cur, MAX_NUMBER+1, "%u,", offset);
-			if(limit)
-				cur+=snprintf(cur, MAX_NUMBER, "%u", limit);
+				cur+=snprintf(cur, MAX_NUMBER+1, "%lu,", offset);
+			if(limit!=SQL_NO_LIMIT)
+				cur+=snprintf(cur, MAX_NUMBER, "%lu", limit);
 			statement=statement_limited;
 		} else
 			statement=astatement;
 
 
-		char *zErr;
 		const char *pzTail;
+		int next_statement_length=0;
 		sqlite3_stmt *SQL;
 		int rc;
-		int i;
 		SQL_Error sql_error;
-		bool failed = false;
+		bool failed=false;
 
 		do{ // cycling through SQL commands
-
-//			MBox(statement, "statement");
-			rc = sqlite3_prepare(connection.handle, statement, -1, &SQL, &pzTail);
-			MBox(pzTail, "tail");
-
-			if( SQLITE_OK!=rc ){
-				MBox(sqlite3_errmsg(connection.handle), "query_error");
-				services._throw(sqlite3_errmsg(connection.handle));
-				sqlite3_free(zErr);
+			rc=pa_sqlite3_prepare(connection.handle, statement, -1, &SQL, &pzTail);
+			next_statement_length=strlen(pzTail);
+			if(rc!=SQLITE_OK){
+				//pa_sqlite3_free((char*)pzTail);
+				_throw(connection, pa_sqlite3_errmsg(connection.handle));
+			}
+			if(!connection.multi_statements && next_statement_length>0){ // multi statements was not allowed but pzTail point to not empty one
+				//pa_sqlite3_free((char*)pzTail);
+				_throw(connection, "multi statements are not allowed until option ?multi_statements=1 in connect string is specified.");
 			}
 			
+			#define CHECK(afailed) if(afailed){ failed=true; goto cleanup; }
 
-			#define CHECK(afailed) if(afailed) { failed=true; goto cleanup; }
-
-			int column_count = sqlite3_column_count(SQL);
+			int column_count=pa_sqlite3_column_count(SQL);
 
-			if(!column_count){  // empty result: insert|delete|update|...
-				rc = sqlite3_step(SQL);
+			if(!column_count){ // empty result: insert|delete|update|...
+				rc=pa_sqlite3_step(SQL);
 			} else {
-
-				for(i=0; i<column_count; i++){
-					const char *column_name = sqlite3_column_name(SQL, i);
-					size_t length = strlen(column_name);
+				for(int i=0; i<column_count; i++){
+					const char *column_name=pa_sqlite3_column_name(SQL, i);
+					size_t length=strlen(column_name);
 
 					char* strm=(char*)services.malloc_atomic(length+1);
 					memcpy(strm, column_name, length+1);
-
-					CHECK(handlers.add_column(sql_error, (const char*)strm, length));
+					const char* str=strm;
+					// transcode column name from ?ClientCharset to $request:charset 
+					if(transcode_needed){
+						services.transcode(str, length,
+							str, length,
+							client_charset,
+							request_charset);
+					}
+							
+					CHECK(handlers.add_column(sql_error, (const char*)str, length));
 				}
 				CHECK(handlers.before_rows(sql_error));
 
-				int column_type;
-				const unsigned char *str;
-				size_t length = 0;
+				const char *str;
+				size_t length=0;
 
 				do{
-					rc = sqlite3_step(SQL);
-					if( rc == SQLITE_ROW ){   // новая строка!!
+					rc=pa_sqlite3_step(SQL);
+					if(rc==SQLITE_ROW){ // new line!!
 
 						CHECK(handlers.add_row(sql_error));
 
-						for(i=0; i<column_count; i++){
-
-							column_type = sqlite3_column_type(SQL, i);
-		
-							// SQLite позволяет поле любого типа получить в виде строки через sqlite3_column_text
-							// просто перекодирует если требуется
-							// а парсер только строковые значения получает
-							// но switch я всё-таки сделал - так, на будущее
-							switch(column_type) {
-								case SQLITE_TEXT:
-									str = sqlite3_column_text(SQL, i);
-									length = strlen((const char*)str);
+						for(int i=0; i<column_count; i++){
+							// SQLite allow to get value of any type using pa_sqlite3_column_text function
+							bool transcode_value=false;
+							int column_type=pa_sqlite3_column_type(SQL, i);
+							switch(column_type){
+								case SQLITE_NULL:
+									length=0;
+									str=NULL;
 									break;
-								case SQLITE_INTEGER:
-									str = sqlite3_column_text(SQL, i);
-									length = strlen((const char*)str);
+								case SQLITE_BLOB:
+									str=(const char*)pa_sqlite3_column_blob(SQL, i);
+									length=(size_t)pa_sqlite3_column_bytes(SQL, i);
 									break;
-								default:
-									str = sqlite3_column_text(SQL, i);
-									length = strlen((const char*)str);
+								case SQLITE_TEXT: // for text transcoding can be required
+								default: // anything else?
+									transcode_value=transcode_needed;
+								case SQLITE_INTEGER:
+								case SQLITE_FLOAT:
+									str=(const char*)pa_sqlite3_column_text(SQL, i);
+									length=(size_t)pa_sqlite3_column_bytes(SQL, i);
 									break;
 							}
 
-							//MBox((const char*)str, "query_in_step");
-
-							char* strm=(char*)services.malloc_atomic(length+1);
-							memcpy(strm, str, length+1);
-
-							CHECK(handlers.add_row_cell(sql_error, (const char*)strm, length));
+							if(length){
+								char* strm=(char*)services.malloc_atomic(length+1);
+								memcpy(strm, str, length);
+								strm[length]=0;
+								str=strm;
+
+								if(transcode_value){
+									// transcode cell value from ?ClientCharset to $request:charset
+									services.transcode(str, length,
+										str, length,
+										client_charset,
+										request_charset);
+								}
+							} else
+								str=0;
+							
+							CHECK(handlers.add_row_cell(sql_error, str, length));
 
 						}
 					}
-				} while( rc == SQLITE_BUSY || rc == SQLITE_ROW );
+				} while(rc==SQLITE_BUSY || rc==SQLITE_ROW);
 
-			}  // if column
+			}
 
-			if( rc == SQLITE_ERROR || rc == SQLITE_MISUSE ){
-				services._throw(sqlite3_errmsg(connection.handle));
+			if(rc==SQLITE_ERROR || rc==SQLITE_MISUSE){
+				_throw(connection, pa_sqlite3_errmsg(connection.handle));
 			}
 
 	cleanup:
-			sqlite3_finalize(SQL);
-			statement = pzTail;
-		} while (strlen(pzTail) > 0);
+			pa_sqlite3_finalize(SQL);
+			statement=pzTail;
+		} while (next_statement_length>0);
 
 		if(failed)
 			services._throw(sql_error);
 	}
 
-private: // sqlite client library funcs
-
-	typedef int (*t_sqlite3_open)(const char *filename, sqlite3 **ppDb); t_sqlite3_open sqlite3_open;
-
-	typedef int (*t_sqlite3_close)(sqlite3 *); t_sqlite3_close sqlite3_close;
-
-	typedef int (*t_sqlite3_exec)(sqlite3*, const char *sql, sqlite3_callback, void *, char **errmsg); t_sqlite3_exec sqlite3_exec;
-
-	typedef void (*t_sqlite3_free)(char *z); t_sqlite3_free sqlite3_free;
-
-	typedef const char *(* t_sqlite3_errmsg)(sqlite3*); t_sqlite3_errmsg sqlite3_errmsg;
-
-	typedef int (* t_sqlite3_prepare)(sqlite3 *db, const char *zSql, int nBytes, sqlite3_stmt **ppStmt, const char **pzTail); t_sqlite3_prepare sqlite3_prepare;
+private:
+	void _begin_transaction(Connection& connection) {
+		if(!connection.autocommit){
+			_execute_cmd(connection, "BEGIN");
+		}
+	}
 
-	typedef int (* t_sqlite3_column_count)(sqlite3_stmt *pStmt); t_sqlite3_column_count sqlite3_column_count;
+	void _execute_cmd(Connection& connection, const char* statement){
+		char* zErr;
+		int rc=pa_sqlite3_exec(connection.handle, statement, 0, 0, &zErr);
+		if(rc!=SQLITE_OK){
+			size_t length=strlen(zErr);
+			char* err_msg=(char *)connection.services->malloc_atomic(length+1);
+			memcpy(err_msg, zErr, length);
 
-	typedef int (* t_sqlite3_finalize)(sqlite3_stmt *pStmt); t_sqlite3_finalize sqlite3_finalize;
+			pa_sqlite3_free(zErr);
+			_throw(connection, err_msg);
+		}
 
-	typedef const char *(* t_sqlite3_column_name)(sqlite3_stmt*,int); t_sqlite3_column_name sqlite3_column_name;
+	}
 
-	typedef int (* t_sqlite3_step)(sqlite3_stmt*); t_sqlite3_step sqlite3_step;
+	void _throw(Connection& connection, const char* aerr_msg){
+		size_t length=strlen(aerr_msg);
+		if(length && _transcode_required(connection)){
+			// transcode server error message from ?ClientCharset to $request:charset 
+			connection.services->transcode(aerr_msg, length,
+				aerr_msg, length,
+				connection.client_charset,
+				connection.services->request_charset());
+		}
+		connection.services->_throw(aerr_msg);
+	}
 
-	typedef int (* t_sqlite3_column_type)(sqlite3_stmt*, int iCol); t_sqlite3_column_type sqlite3_column_type;
+	bool _transcode_required(Connection& connection, const char* charset=0){
+		return (strcmp(charset?charset:connection.client_charset, connection.services->request_charset())!=0);
+	}
 
-	typedef const unsigned char *(* t_sqlite3_column_text)(sqlite3_stmt*, int iCol); t_sqlite3_column_text sqlite3_column_text;
 
 private: // sqlite client library funcs linking
 
-	const char *dlink(const char *dlopen_file_spec) {
-		if(lt_dlinit())
-			return lt_dlerror();
-        lt_dlhandle handle=lt_dlopen(dlopen_file_spec);
-        if (!handle) {
-            if(const char* result=lt_dlerror())
-            	return result;
+	const char *dlink(char *dlopen_file_spec) {
+		if(lt_dlinit()){
+			if(const char* result=lt_dlerror())
+				return result;
+			return "can not prepare to dynamic loading";
+		}
 
+		lt_dlhandle handle;
+		do {
+			char *next=lsplit(dlopen_file_spec, ',');
+			handle=lt_dlopen(dlopen_file_spec);
+			dlopen_file_spec=next;
+		} while (!handle && dlopen_file_spec);
+
+		if(!handle){
+			if(const char* result=lt_dlerror())
+				return result;
 			return "can not open the dynamic link module";
 		}
 
 		#define DSLINK(name, action) \
-			name=(t_##name)lt_dlsym(handle, #name); \
-				if(!name) \
+			pa_##name=(t_##name)lt_dlsym(handle, #name); \
+				if(!pa_##name) \
 					action;
 
 		#define DLINK(name) DSLINK(name, return "function " #name " was not found")
@@ -355,6 +539,7 @@ private: // sqlite client library funcs
 		
 		DLINK(sqlite3_open);
 		DLINK(sqlite3_close);
+		DLINK(sqlite3_busy_timeout);
 		DLINK(sqlite3_exec);
 		DLINK(sqlite3_free);
 		DLINK(sqlite3_errmsg);
@@ -365,6 +550,17 @@ private: // sqlite client library funcs
 		DLINK(sqlite3_step);
 		DLINK(sqlite3_column_type);
 		DLINK(sqlite3_column_text);
+		DLINK(sqlite3_column_blob);
+		DLINK(sqlite3_column_bytes);
+#ifdef PA_REGEXP
+		DLINK(sqlite3_create_function);
+		DLINK(sqlite3_value_text);
+		DLINK(sqlite3_get_auxdata);
+		DLINK(sqlite3_set_auxdata);
+		DLINK(sqlite3_result_error);
+		DLINK(sqlite3_result_error_nomem);
+		DLINK(sqlite3_result_int);
+#endif
 		return 0;
 	}