ios sqlite中写入图片二进制数据及读取

sqlite数据库插入和读取图片数据 (for ios)


在iOS下用sqlite数据库存储图片，先把你的图片转换成 NSData 形式，然后在数据库添加一行 blob 数据


假定数据库中存在表 test_table(name,image), 下面代码将图片文件test.png的二进制数据写到sqlite数据库：


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char *name = "test";
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NSString * nameString = [NSString stringWithCString:name encoding:NSUTF8StringEncoding];
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NSString * filePath = [[NSBundle mainBundle] pathForResource:nameString ofType:@"png"];
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if ([[NSFileManager defaultManager] fileExistsAtPath:filePath])
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{
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    NSData * imgData = UIImagePNGRepresentation([UIImage imageWithContentsOfFile:filePath]);
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    const  char * sequel = "insert into test_table(name,image) values(?,?)";
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    sqlite3_stmt * update;
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    if (sqlite3_prepare_v2(database, sequel, -1, &update, NULL) == SQLITE_OK)
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    {
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        sqlite3_bind_text(update, 1, name, -1, NULL);
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        sqlite3_bind_blob(update, 2, [imgData bytes], [imgData length], NULL);
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        if( sqlite3_step(update) == SQLITE_DONE)
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        {
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           NSLog(@"已经写入数据");
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        }
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        sqlite3_finalize(update);
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    } 
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}
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else
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{
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    NSLog(@"文件不存在");
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}
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下面代码从数据库中读取图片二进制数据，然后显示图片：
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const char * sequel = "select image from test_table where name=?";
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sqlite3_stmt * getimg;
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if (sqlite3_prepare_v2(database, sequel, -1, &getimg, NULL) == SQLITE_OK)
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{
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    char *name = "test";
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    sqlite3_bind_text(update, 1, name, -1, NULL);
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    if(sqlite3_step(getimg)  == SQLITE_ROW)
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    {
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        int bytes = sqlite3_column_bytes(getimg, 0);
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        Byte * value = (Byte*)sqlite3_column_blob(getimg, 1);
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        if (bytes !=0 && value != NULL)
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        {
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            NSData * data = [NSData dataWithBytes:value length:bytes];
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            UIImage * img = [UIImage imageWithData:data];
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            UIImageView * aview =[[UIImageView alloc] initWithFrame:
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                                    CGRectMake(0.0, 0.0, IMAGE_WIDTH, IMAGE_HEIGHT)];
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            aview.image = img;
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            [self.view addSubview:aview];
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            [aview release];
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         }
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     }
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     sqlite3_finalize(getimg);
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}




例2:


存储图片:


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// Save Small Image Data by given main url  
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- (void) SaveImagesToSql: (NSData*) imgData :(NSString*) mainUrl 
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{ 
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    NSLog( @"\n*****Save image to SQLite*****\n" ); 
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    const char* sqliteQuery = "INSERT INTO IMAGES (URL, IMAGE) VALUES (?, ?)"; 
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    sqlite3_stmt* statement; 
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    if( sqlite3_prepare_v2(articlesDB, sqliteQuery, -1, &statement, NULL) == SQLITE_OK ) 
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    { 
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        sqlite3_bind_text(statement, 1, [mainUrl UTF8String], -1, SQLITE_TRANSIENT); 
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        sqlite3_bind_blob(statement, 2, [imgData bytes], [imgData length], SQLITE_TRANSIENT); 
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        sqlite3_step(statement); 
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    } 
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    else NSLog( @"SaveBody: Failed from sqlite3_prepare_v2. Error is:  %s", sqlite3_errmsg(articlesDB) ); 
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    // Finalize and close database. 
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    sqlite3_finalize(statement); 
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}
读取图片:
view sourceprint?
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// Load images from data base with given image url  
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- (NSData*) LoadImagesFromSql: (NSString*) imageLink 
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{ 
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    NSData* data = nil; 
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    NSString* sqliteQuery = [NSString stringWithFormat:@"SELECT IMAGE FROM IMAGES WHERE URL = '%@'", imageLink];     
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    sqlite3_stmt* statement; 
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    if( sqlite3_prepare_v2(articlesDB, [sqliteQuery UTF8String], -1, &statement, NULL) == SQLITE_OK ) 
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    { 
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        if( sqlite3_step(statement) == SQLITE_ROW ) 
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        { 
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            int length = sqlite3_column_bytes(statement, 0); 
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            data       = [NSData dataWithBytes:sqlite3_column_blob(statement, 0) length:length]; 
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        } 
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    } 
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    // Finalize and close database. 
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    sqlite3_finalize(statement); 
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    return data; 
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}