【學習筆記】sqlite 数据库读写图片

用 iPhone 的 sqlite 数据库读写图片，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，代码如下（data就是图片） ：

NSMutableString *insertSql = [[NSMutableString alloc] initWithString:@"INSERT INTO "];
[insertSql appendString:BLOB];
[insertSql appendString:@" ("];
[insertSql appendString:BLOB_DATA];
[insertSql appendString:@") VALUES(?1)"];
sqlite3_stmt *insert_statement = nil;
sqlite3 *database = 你的数据库;
if (sqlite3_prepare_v2(database, [insertSql UTF8String], -1, &insert_statement, NULL) == SQLITE_OK) {
sqlite3_bind_blob(insert_statement, 1, [data bytes], [data length], NULL);
if(sqlite3_step(insert_statement) != SQLITE_DONE) {
NSLog(@"Db error %s", sqlite3_errmsg(database));
}
} else {
NSLog(@"Db error %s", sqlite3_errmsg(database));
}
sqlite3_finalize(insert_statement);
[insertSql release];

//获取表格中所有的记录，放到数组fChannels中。

- (void) getChannels:(NSMutableArray*)fChannels{

char *sql = "SELECT * FROM channels where id = 2";

sqlite3_stmt *statement;

int success = (sqlite3_prepare_v2(database_, sql, -1, &statement, NULL));

if (success == SQLITE_OK) {

if (SQLITE_ROW == sqlite3_step(statement)) {

const unsigned char *cid = sqlite3_column_text(statement, 1);//获取log的字符串，’1‘是第2列

const unsigned char *dtitle = sqlite3_column_text(statement, 2);

Byte* imageData = (Byte*)sqlite3_column_blob(statement, 3);

int imageLen    = sqlite3_column_int(statement, 4);

_titleLabel.text = [NSString stringWithUTF8String:(char *)dtitle];

_iv.image = [UIImage imageWithData:[NSData dataWithBytes:imageData length:imageLen]];

sqlite3_finalize(statement);

}

sqlite3_finalize(statement);

}

}