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3. The subsystem "Database" (TBDS)

Subsystem «Databases» is represented by the object TBDS, which contains a modular objects of the following types of DB TTipBD. Each type of database contains objects of individual databases of that type TBD. Each database in its turn, contains the objects of their tables TTable (Fig. 3).

Fig. 3. Hierarchical structure of the database subsystem.

The subsystem provides the basic functions to access the type of database, as well as generalized functions for the manipulation of the databases and tables. For example, to hide the source of data, which may be a configuration file, the functions of an abstract access to the data source are provided. For the storage system-wide data the system table and the function of the abstract to access it are provided. Consequently, system-wide data can be stored in the configuration file and in the database table. Priority source, in this case, is the database table.

Being a modular object, the type of database (TTipBD) provides access to the implementation of the mechanism of one or another database. Access is made through a public databases of the module of a given type of database. Open/registered database is described in the table of databases to be opened or in the configuration file. There is, the so-called, the working database, which is always opens and is shown in the configuration file. DB which support the SQL-queries can grant access based on direct SQL-queries.

While working, the components of the OpenSCADA system open tables (TTable) available in the database and work with them.

3.1. Object of subsystem «Database» (TBDS)

Data:
Flags of the queries to the system table (enum – TDBS::ReqGen):

• OnlyCfg -- request only to the configuration file.
• UseTranslate -- use the translation of text variable.

Public methods:

• int subVer( ); -- Subsystem version.
• static string realDBName( const string &bdn ); -- Conversion of the full template name of the database or table (of view *.*.myTbl) in the real name. Actually the replacement of the special elements '*' by the elements of the working DB.
• void dbList( vector<string> &ls, bool checkSel = false ); -- Ñïèñîê äîñòóïíûõ ÁÄ. <checkSel> óêàçûâàåò íà íåîáõîäèìîñòü ïðîâåðêè ôàêòà çàãðóçêè èç âûáðàííîé ÁÄ è âñòàâêè â ñïèñîê ÁÄ òîëüêî âûáðàííîé.
• AutoHD<TTable> open( const string &bdn, bool create = false ); -- Îòêðûòèå òàáëèöû <bdn> ÁÄ ïî å¸ ïîëíîìó ïóòè ñ ñîçäàíèåì <create> â ñëó÷àå îòñóòñòâèÿ.
• void close( const string &bdn, bool del = false ); -- Çàêðûòèå òàáëèöû <bdn> ÁÄ ïî å¸ ïîëíîìó ïóòè ñ âîçìîæíîñòüþ óäàëåíèÿ ïîñëå çàêðûòèÿ <del>.
• bool dataSeek( const string &bdn, const string &path, int lev, TConfig &cfg ); -- Îáùåå ñêàíèðîâàíèå çàïèñåé èñòî÷íèêà äàííûõ.  êà÷åñòâå èñòî÷íèêà âûñòóïàåò êîíôèãóðàöèîííûé ôàéë èëè ÁÄ.  ñëó÷àå îòñóòñòâèÿ ÁÄ èñïîëüçóåòñÿ êîíôèãóðàöèîííûé ôàéë. Åñëè èìÿ ÁÄ <bdn> èëè ïóòü <path> êîíôèãóðàöèîííîãî ôàéëà íå óêàçàíû, òî èõ îáðàáîòêà ïðîïóñêàåòñÿ.
• bool dataGet( const string &bdn, const string &path, TConfig &cfg ); -- Ïîëó÷åíèå çàïèñè èç èñòî÷íèêà äàííûõ (ÁÄ èëè êîíôèãóðàöèîííûé ôàéë). Åñëè èìÿ ÁÄ <bdn> èëè ïóòü <path> êîíôèãóðàöèîííîãî ôàéëà íå óêàçàíû, òî èõ îáðàáîòêà ïðîïóñêàåòñÿ.
• void dataSet( const string &bdn, const string &path, TConfig &cfg ); -- Óñòàíîâèòü/ñîõðàíèòü çàïèñü â èñòî÷íèêå äàííûõ (ÁÄ èëè êîíôèãóðàöèîííûé ôàéë). Åñëè èìÿ ÁÄ <bdn> èëè ïóòü <path> êîíôèãóðàöèîííîãî ôàéëà íå óêàçàíû, òî èõ îáðàáîòêà ïðîïóñêàåòñÿ.
• bool dataDel( const string &bdn, const string &path, TConfig &cfg, bool useKeyAll = false ); -- Óäàëåíèå çàïèñè èç èñòî÷íèêà äàííûõ (ÁÄ èëè êîíôèãóðàöèîííûé ôàéë). Åñëè èìÿ ÁÄ <bdn> èëè ïóòü <path> êîíôèãóðàöèîííîãî ôàéëà íå óêàçàíû, òî èõ îáðàáîòêà ïðîïóñêàåòñÿ. <useKeyAll> èñïîëüçóåòñÿ äëÿ óêàçàíèÿ íåîáõîäèìîñòè óñòàíîâêè âñåõ êëþ÷åé äëÿ èñïîëüçîâàíèÿ èõ ïðè óäàëåíèè ñ âîññòàíîâëåíèåì èñõîäíîãî ñîñòîÿíèé âûáîðà êëþ÷åé ïðè âûõîäå èç ôóíêöèè. Åñëè ýòîò ôëàã íå óñòàíîâëåí, òî èñïîëüçóþòñÿ ðàíåå âûáðàííûå êëþ÷è äëÿ âûïîëíåíèÿ îïåðàöèè.
• static string genDBGet( const string &path, const string &oval = "", const string &user = "root", char rFlg = 0 ); -- Ïîëó÷èòü îáùåñèñòåìíûå äàííûå èç êîíôèãóðàöèîííîãî ôàéëà èëè ñèñòåìíîé òàáëèöû îò èìåíè ïîëüçîâàòåëÿ <user>. Åñëè äàííûå îòñóòñòâóþò, òî âîçâðàùàåòñÿ çíà÷åíèé <oval>.
• static void genDBSet( const string &path, const string &val, const string &user = "root", char rFlg = 0 ); -- Óñòàíîâèòü/ñîõðàíèòü îáùå-ñèñòåìíûå äàííûå â êîíôèãóðàöèîííîì ôàéëå èëè ñèñòåìíîé òàáëèöå îò èìåíè ïîëüçîâàòåëÿ <user>.
• string fullDBSYS( ); -- Ïîëíîå èìÿ ñèñòåìíîé òàáëèöû.
• string fullDB( ); -- Ïîëíîå èìÿ òàáëèöû ñ îïèñàíèåì çàðåãèñòðèðîâàííûõ ÁÄ.
• TElem &openDB_E( ) -- Ñòðóêòóðà òàáëèöû çàðåãèñòðèðîâàííûõ ÁÄ.
• AutoHD<TTipBD> at( const string &iid ) -- Îáðàùåíèå ê ìîäóëþ ÁÄ (òèïó ÁÄ).
• string optDescr( ); -- Ëîêàëèçîâàííàÿ ïîìîùü ïî îïöèÿì êîìàíäíîé ñòðîêè è ïàðàìåòðàì êîíôèãóðàöèîííîãî ôàéëà.