![]() ![]() The sample app defines a TodoItemDatabase class for this purpose. This class centralizes query logic and simplifies the management of database initialization, making it easier to refactor or expand data operations as the app grows. Create a database access classĪ database wrapper class abstracts the data access layer from the rest of the app. For more information about SQLiteOpenFlags, see Opening A New Database Connection on. You may need to specify different flags depending on how your database will be used. ProtectionNone: The database file isn't encrypted.ProtectionCompleteUntilFirstUserAuthentication: The file is encrypted until after the user has booted and unlocked the device.ProtectionCompleteUnlessOpen: The file is encrypted until it's opened but is then accessible even if the user locks the device.ProtectionComplete: The file is encrypted and inaccessible while the device is locked.SharedCache: The connection will participate in the shared cache, if it's enabled.ReadWrite: The connection can read and write data. ![]() PrivateCache: The connection will not participate in the shared cache, even if it's enabled.NoMutex: The connection is opened in multi-threading mode. ![]() FullMutex: The connection is opened in serialized threading mode.Create: The connection will automatically create the database file if it doesn't exist.The SQLiteOpenFlag enum supports these values: In this example, the constants file specifies default SQLiteOpenFlag enum values that are used to initialize the database connection. Path.Combine(FileSystem.AppDataDirectory, DatabaseFilename) create the database if it doesn't exist Public const SQLite.SQLiteOpenFlags Flags = Public const string DatabaseFilename = "TodoSQLite.db3" The sample project includes a Constants.cs file that provides common configuration data: public static class Constants In addition to sqlite-net-pcl, you temporarily need to install the underlying dependency that exposes SQLite on each platform:Ĭonfiguration data, such as database filename and path, can be stored as constants in your app. Something is lost somewhere, I can’t understand what the problem is.SQLite.NET is a third-party library that's supported from the praeclarum/sqlite-net repo. It seems to be written and read, the size in bytes is the same, but the resulting 123.png file is not read as a picture. Image1->Picture->LoadFromStream(ms) // error Memo1->Lines->Add("read: " + IntToStr(bytes)) ![]() Memo1->Lines->Add("Error open " + IntToStr(error)) Rc = sqlite3_blob_open(db,"main","images","data",1,0,&data) Įrror = sqlite3_blob_read(data,zBlob,bytes,0) Memo1->Lines->Add("Error close " + IntToStr(error)) Memo1->Lines->Add("Error write " + IntToStr(error)) Rc = sqlite3_blob_write(blob, f, f->Size, 0) Memo1->Lines->Add("size of BLOB : " + (String)sqlite3_blob_bytes(blob)) Rc = sqlite3_blob_open(db, "main", "images", "data", rowid, 1, &blob) Memo1->Lines->Add("Insert statement didn't work") sqlite3_bind_blob(insert_stmt,4,f, f->Size,SQLITE_STATIC) // That doesn't work too Sqlite3_bind_zeroblob(insert_stmt, 4, filesize) Sqlite3_bind_text(insert_stmt, 3, Insert_data.c_str(), -1, 0) Rc = sqlite3_prepare_v2(db, Insert_data.c_str(), -1, &insert_stmt, NULL) Insert_data = "INSERT INTO images(id, pic_id, picture_name, data) VALUES (?, ?, ?, ?) " TFileStream *f = new TFileStream(Path, fmOpenRead) Image1->Picture->LoadFromFile(OpenDialog1->FileName) Memo1->Lines->Add(OpenDialog1->FileName) Image Writing Code AnsiString Insert_data I'm reading forums for three days already but can't find a solution. Trying to save PNG image to SQLite base and then get it back. ![]()
0 Comments
Leave a Reply. |