Sqlite数据库插入和读取图片数据

　2013-01-14 16:02:12　来源：WEB开发网　　　

核心提示： 在iOS下用sqlite数据库存储图片，先把你的图片转换成 NSData 形式，Sqlite数据库插入和读取图片数据，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：CHAR *name =

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：

CHAR *name = "test";
NSString * nameString = [NSString stringWithCString:name encoding:NSUTF8StringEncoding];
NSString * filePath = [[NSBundle mainBundle] pathForResource:nameString ofType:@"png"];
IF ([[NSFileManager defaultManager] fileExistsAtPath:filePath])
{
    NSData * imgData = UIImagePNGRepresentation([UIImage imageWithContentsOfFile:filePath]);
    const  CHAR * sequel = "insert into test_table(name,image) values(?,?)";
 
    sqlite3_stmt * UPDATE;
    IF (sqlite3_prepare_v2(DATABASE, sequel, -1, &UPDATE, NULL) == SQLITE_OK)
    {
        sqlite3_bind_text(UPDATE, 1, name, -1, NULL);
        sqlite3_bind_blob(UPDATE, 2, [imgData bytes], [imgData LENGTH], NULL);
        IF( sqlite3_step(UPDATE) == SQLITE_DONE)
        {
           NSLog(@"已经写入数据");
        }
        sqlite3_finalize(UPDATE);
    }  
}
ELSE
{
    NSLog(@"文件不存在");
}

下面代码从数据库中读取图片二进制数据，然后显示图片：
const CHAR * sequel = "select image from test_table where name=?";
sqlite3_stmt * getimg;
IF (sqlite3_prepare_v2(DATABASE, sequel, -1, &getimg, NULL) == SQLITE_OK)
{
    CHAR *name = "test";
    sqlite3_bind_text(UPDATE, 1, name, -1, NULL);
    IF(sqlite3_step(getimg)  == SQLITE_ROW)
    {
        INT bytes = sqlite3_column_bytes(getimg, 0);
        Byte * VALUE = (Byte*)sqlite3_column_blob(getimg, 1);
        IF (bytes !=0 && VALUE != NULL)
        {
            NSData * DATA = [NSData dataWithBytes:VALUE LENGTH:bytes];
            UIImage * img = [UIImage imageWithData:DATA];
            UIImageView * aview =[[UIImageView alloc] initWithFrame:
　　　　　　　　　　　　　　　　　　CGRectMake(0.0, 0.0, IMAGE_WIDTH, IMAGE_HEIGHT)];
            aview.image = img;
            [SELF.VIEW addSubview:aview];
            [aview release];
         }
     }
     sqlite3_finalize(getimg);
}

例2:存储图片

/ Save Small Image Data by given main url   
- (void) SaveImagesToSql: (NSData*) imgData :(NSString*) mainUrl  
{  
    NSLog( @"\n*****Save image to SQLite*****\n" );  
  
    const char* sqliteQuery = "INSERT INTO IMAGES (URL, IMAGE) VALUES (?, ?)";  
    sqlite3_stmt* statement;  
  
    if( sqlite3_prepare_v2(articlesDB, sqliteQuery, -1, &statement, NULL) == SQLITE_OK )  
    {  
        sqlite3_bind_text(statement, 1, [mainUrl UTF8String], -1, SQLITE_TRANSIENT);  
        sqlite3_bind_blob(statement, 2, [imgData bytes], [imgData length], SQLITE_TRANSIENT);  
        sqlite3_step(statement);  
    }  
    else NSLog( @"SaveBody: Failed from sqlite3_prepare_v2. Error is:  %s", sqlite3_errmsg(articlesDB) );  
  
    // Finalize and close database.  
    sqlite3_finalize(statement);  
}

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