iphone - 将图像存储和检索到 iphone 的 sqlite 数据库中

Question

我正在尝试从 sqlite 数据库存储和检索图像和文本..我的 saveDatabase 编码工作正常..但我不知道它是否保存在我的数据库中..这是我的代码..

    sqlite3 *database;
    dbName=@"dataTable.sqlite";
    NSArray *documentpath=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentdir=[documentpath objectAtIndex:0];
    dbPath=[documentdir stringByAppendingPathComponent:dbName];
    sqlite3_stmt *compiledStmt;
   if(sqlite3_open([dbPath UTF8String], &database)==SQLITE_OK){
        NSLog(@"Name:%@,Company:%@,URL:%@",model.personName,model.companyName,model.imgurl);
//        NSString *sqlStatement=[NSString stringWithFormat:@"insert or ignore into Persons(PersonName,CompanyName,ImgUrl)values(\"%@\",\"%@\",\"%@\")",model.personName,model.companyName,model.imgurl];
//           const char *insertSQL=[sqlStatement UTF8String];

       const char *insertSQL="insert or ignore into Persons(PersonName,CompanyName,ImgUrl,UserImage)values(?,?,?,?)";
       sqlite3_bind_text(compiledStmt,1,[model.personName UTF8String],-1,SQLITE_TRANSIENT);
       sqlite3_bind_text(compiledStmt,2,[model.companyName UTF8String],-1,SQLITE_TRANSIENT);
       sqlite3_bind_text(compiledStmt,3,[model.imgurl UTF8String],-1,SQLITE_TRANSIENT);
       NSData *imageData=UIImagePNGRepresentation(imageView.image);
       sqlite3_bind_blob(compiledStmt, 4, [imageData bytes], [imageData length], NULL);
    if(sqlite3_prepare_v2(database,insertSQL, -1, &compiledStmt, NULL)==SQLITE_OK){
        sqlite3_step(compiledStmt);

//    char *errMsg;
//        sqlite3_exec(database, insertSQL, NULL,compiledStmt,&errMsg);
        NSLog(@"Add to Favourites");

当我尝试检索我的数据库时出现错误..

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** +[NSString stringWithUTF8String:]: NULL cString'

这是我读取数据库的代码..

    sqlite3 *database;

    favArray=[[NSMutableArray alloc]init];
    if(sqlite3_open([dbPath UTF8String],&database)==SQLITE_OK)
    {
        const char *sqlStatement="select * from Persons";
        sqlite3_stmt *compiledStatement;

        if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL)==SQLITE_OK)
        {
            while (sqlite3_step(compiledStatement)==SQLITE_ROW) 
            {
                int personId = sqlite3_column_int(compiledStatement,0);

                NSString *personName=[NSString stringWithUTF8String:(char *) sqlite3_column_text(compiledStatement, 1)];

                NSString *companyName=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];

                NSString *imgurl=[NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 3)];
                int length = sqlite3_column_bytes(compiledStatement, 4);
//                NSData *data       = [NSData dataWithBytes:sqlite3_column_blob(compiledStatement, 4) length:length];
                NSString *imageString=[NSString stringWithCharacters:sqlite3_column_blob(compiledStatement, 4) length:length];
                UIImage *personImage=[UIImage imageNamed:imageString];

                Favourites *favourites=[[Favourites alloc]initWithPersonId:personId personName:personName companyName:companyName imgurl:imgurl personImage:personImage];
                [favArray addObject:favourites];
            }
        }sqlite3_finalize(compiledStatement);
    }
    sqlite3_close(database);

我认为我在通过错误的数据访问方式读取数据库时做错了..任何人都可以帮助我从数据库中获取图像...

Answer 1

最后我发现我在哪个地方遇到了问题...首先我检查了数据存储在我的模拟器数据库中..它没有存储.所以我发现我的插入编码有问题...这是我m 在 prepare 语句之前绑定(bind)数据...我找到的答案是..

if(sqlite3_prepare_v2(database,insertSQL, -1, &compiledStmt, NULL)==SQLITE_OK){

sqlite3_bind_text(compiledStmt,1,[model.personName UTF8String],-1,SQLITE_TRANSIENT);
       sqlite3_bind_text(compiledStmt,2,[model.companyName UTF8String],-1,SQLITE_TRANSIENT);
       sqlite3_bind_text(compiledStmt,3,[model.imgurl UTF8String],-1,SQLITE_TRANSIENT);
       NSData *imageData=UIImagePNGRepresentation(imageView.image);
       sqlite3_bind_blob(compiledStmt, 4, [imageData bytes], [imageData length], NULL);

sqlite3_step(compiledStmt);

//    char *errMsg;
//        sqlite3_exec(database, insertSQL, NULL,compiledStmt,&errMsg);
        NSLog(@"Add to Favourites");
}