iPhone SQLite 新增一直失敗找到原因了

一開始的部份就不再說明教學了(是我太懶)，讓大家參考這三個網站

1.iPhone Tutorial: Using SQLite3 database
http://ved-dimensions.blogspot.com/2009/03/iphone-development-sqlite3-populating.html

2.SQLite Tutorial - Saving images in the database
http://www.iphonesdkarticles.com/2009/02/sqlite-tutorial-saving-images-in.html

3.How do you insert an image into SQLite on the iPhone?
http://stackoverflow.com/questions/737443/how-do-you-insert-an-image-into-sqlite-on-the-iphone

今天為了要讓iPhone能透過讀取xml方式，取得更新的圖片url，得到url之後希望把圖片存到SQLite內，搞了超久一直失敗...
首先出現out of memory，光這個問題就找一個下午=.=，最後認真看到國外網友，它點出了db沒有正確讀到才會發生問題，下面這隻method就是連線成功的方式

- (void) getNewDBConnection{

NSFileManager *fileManager = [NSFileManager defaultManager];

NSError *error;

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

NSString *documentsDirectory = [paths objectAtIndex:0];

NSString *path = [documentsDirectory stringByAppendingPathComponent:@"data.sqlite"];

BOOL success = [fileManager fileExistsAtPath:path];

if (sqlite3_open([path UTF8String], &database) == SQLITE_OK) {

NSLog(@"Database Successfully Opened :)");

} else {

NSLog(@"Error in opening database :(");

}

}

接下來連線成功之後遇到第二個error : no such table: item ，這個問題也讓人很吐血，明明在resource下有一個data.sqlite，我也用Firefox plugin 的SQLite Manager 建好table與欄位，為什麼會告訴我找不到item這個table呢。最後我把上面的method中的path路徑 NSlog出來才看到原來根本不是在resource下的data.sqlite，原來它存取的是/Users/Maccc/Library/Application Support/iPhone Simulator/4.0/Applications/87386C6E-CCBC-48BF-A121-CF9900D4E0C3/Documents/data.sqlite

insert 至db的method

- (void) addData:(UIImage*)image {

NSString *title=[NSString stringWithString:@"test"];

NSData *ImageData = UIImagePNGRepresentation(image);

NSInteger Imagelen = [ImageData length];

if(addStmt == nil) {

const char *sql = "insert into item(title,imageData) values(?,?)";

if(sqlite3_prepare_v2(database, sql, -1, &addStmt, NULL) != SQLITE_OK)

NSLog(@"Error while creating add statement. '%s'", sqlite3_errmsg(database));

}

sqlite3_bind_text(addStmt, 1, [title UTF8String], -1, SQLITE_TRANSIENT);

sqlite3_bind_blob(addStmt, 2, [ImageData bytes], Imagelen, SQLITE_TRANSIENT);

if(SQLITE_DONE != sqlite3_step(addStmt))

NSLog(@"Error while inserting data. '%s'", sqlite3_errmsg(database));

else

sqlite3_last_insert_rowid(database);

//Reset the add statement.

sqlite3_reset(addStmt);

}

如果你有要轉換UImage為NSData可以用此method

- (UIImage*)loadImageFromUrl:(NSString*)url

{

NSURL *picUrl = [NSURL URLWithString:url];

NSData *picData = [NSData dataWithContentsOfURL:picUrl];

UIImage *image = [UIImage imageWithData:picData];

return image;

}

這樣你轉完後就可以存進db了..