ds - Data Access System

Sqlite (read-write), Ms DAO mdb (read-write), Ms SQL (read-only), databases access system.

DS is an easy to use C++ SQLite3, DAO, MsSQL C++ based wrapper.

Provides a Recordset (MFC: CDaoRecordSet, CRecordset) like interface for a SQLite3, MsSQL, DAO databases.

You can access sqlite database in the same way as mdb file with the minimal code changes inside your project.

Text, Long/Integer, Blob, Double/Real field types are supported.

Text field type addition: Json format support. RapidJson used as backend. (PicoJson, sajson also can be used as backends. RapidJson used as the fastest one.)

New backend to read json files: simdjson: Parsing gigabytes of JSON per second.

Use namespace ds_json::read to acceess simdjson.

dsTable loader(&db, L"Table_Name");
loader.MoveFirst(); // take the first record
ds_json::read::object obj;
ds_json::str2obj(std::move(loader.GetFieldStringUTF8("json_data")), obj);

ds_json::read::array obj_array;
obj.GetArray("json_array", obj_array);
for (const ds_json::read::object &obj : obj_array) {
	obj.GetTextUtf8("json_field");
}

If you're a NoSQL type of person and SQL based database usage can not be avoided, then this might fit the bill perfectly.

DS is an exception free code.

Visual Studio Workspace Generation

cd DBUtils
cmake.exe CMakeLists.txt

Samples:

dsDatabase db;
db.OpenDB(L"database.sqlite"); // sqlite database 
//db.OpenDB(L"database.mdb"); // MS mdb database 

dsTable loader(&db, L"Table_Name");
loader.AddNew();
    // after AddNew you can always retrieved new record key
    int nId = loader.GetFieldLong(L"ID"); 
    loader.SetFieldString(L"Code", L"My_Code");
loader.Update();

loader.SeekIndex(L"ID", nId);
loader.GetFieldString(L"Code");
loader.Edit();
    loader.SetFieldString(L"Code", L"New_Code");
loader.Update();

class CCodeDescrLoader : public dsTable
{
public:
    CCodeDescrLoader(dsDatabase *pDatabase)
       : dsTable(pDatabase, L"MyTableName") { }
    virtual ~CCodeDescrLoader() { }

public:
    KEY_LONG(Id,      "ID");
    KEY_TEXT(Code,    "CODE");
    FIELD_TEXT(Descr, "DESCRIPTION");
    FIELD_JSON(Data,  "DATA"); // Json based field
	 JSON_TEXT(Remark, "Remark"); // Data.Remark
	 JSON_INT32(Order,  "Order"); // Data.Order
	 // NOTE: new fields can be always added, old fields can be always deleted
	 // no changes are required in the sqlite or mdb file/database structure.
};

CCodeDescrLoader loader(&db);
loader.Flush(); // delete all records from the MyTableName
loader.AddNew();
   int nNewId = loader.GetId();
   loader.SetCode(L"New");
   loader.SetDescr(L"Descr");
   ds_json::object obj;
   	CCodeDescrLoader::SetRemark(obj, "MyRemark");
	CCodeDescrLoader::SetOrder(obj,  2);
   loader.SetData(obj); // do store json data
VERIFY(loader.Update());

loader.DeleteById(nNewId); // do delete one record ID=nNewId
// do delete all records from the Table1 with the code value: New
loader.DeleteAllByCode(L"New"); 

// do iterate all Table1 records and do retrieve code values
std::vector<std::wstring> codes;
if ( loader.MoveFirst() )
{
    while ( !loader.IsEOF() ) )
    {
        std::wstring sCode = loader.GetCode(); 
	codes.push_back(sCode); 
        loader.MoveNext();
    }
}

void OnDatabaseError(const wchar_t* sError) 
{
    TRACE(sError); TRACE(L"\n");
}

dsDatabase db;
db.OpenDB(_T("database.mdb")); 
// Exception free code, do handle all errors through the defined function
db.SetErrorHandler(OnDatabaseError);