IOS开发-数据库总结

    // NSUserDefaults 默认    NSUserDefaults *userDefaults =  [NSUserDefaults standardUserDefaults];    [userDefaults setObject:@"skyming" forKey:@"username"];    [userDefaults setObject:[NSDate date] forKey:@"date"];    [userDefaults setObject:@[@"a1",@"a2"] forKey:@"array"];    [userDefaults setInteger:6174 forKey:@"code"];    NSLog(@"userDefaults: %@",[userDefaults dictionaryRePResentation]);        NSString *username = [userDefaults objectForKey:@"username"];    NSDate *date = [userDefaults objectForKey:@"date"];    NSArray *array = [userDefaults objectForKey:@"array"];    NSInteger code = [userDefaults integerForKey:@"code"];        NSLog(@"username: %@  date:%@  /n array: %@ code: %d", username, date, array, code);    [userDefaults synchronize];    // NSUserDefaults 自定义    NSUserDefaults *defaults = [[NSUserDefaults alloc] init];    [defaults setPersistentDomain:[NSDictionary dictionaryWithObject:@"Hello" forKey:@"World"] forName:@"com.Sensoro.DefaultsTest"];    [defaults synchronize];//  数组    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);      NSString *docPath = [paths objectAtIndex:0];      NSString *myFile = [docPath stringByAppendingPathComponent:@"my.list"];      //读取文件      NSArray *array = [[NSArray alloc] initWithContentsOfFile:myFile];      //操作完若修改了数据则，写入文件      [array writeToFile:myFile atomically:YES];  

 #pragma mark -#pragma NSCoding协议实现实现- (void)encodeWithCoder:(NSCoder *)aCoder{   //encoder    [aCoder encodeObject:self.username forKey:@"username"];    [aCoder encodeObject:self.passWord forKey:@"password"];}- (id)initWithCoder:(NSCoder *)aDecoder{    //decoder    if (self = [super init]) {        self.username = [aDecoder decodeObjectForKey:@"username"];        self.password =  [aDecoder decodeObjectForKey:@"password"];    }    return self;}#pragma NSCopying协议实现- (id)copyWithZone:(NSZone *)zone{    DSObj *copy = [[[self class] allocWithZone:zone] init];    return copy;}// 读取        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *docPath = [paths objectAtIndex:0];    NSString *myFile = [docPath stringByAppendingPathComponent:@"dsObj.list"];        //写入归档文件    NSMutableData *datawrite = [[NSMutableData alloc] init];    NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:datawrite];    [archiver encodeObject:test forKey:@"data"];    [archiver finishEncoding];    [datawrite writeToFile:myFile atomically:YES];        //读取归档文件    NSData *data = [[NSMutableData alloc] initWithContentsOfFile:myFile];    NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];    DSObj *testread = [unarchiver decodeObjectForKey:@"data"];    [unarchiver finishDecoding];    NSLog(@"DSObjRead: %@ %@",[testread username], [testread password]);

//open database- (void)openDataBase{    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *docPath = [paths objectAtIndex:0];    NSString *myFile = [docPath stringByAppendingPathComponent:@"data.db"];        if (sqlite3_open([myFile UTF8String], &database)==SQLITE_OK)    {        NSLog(@"open sqlite db ok.");    }    else    {        NSLog( @"can not open sqlite db " );                //close database        sqlite3_close(database);    }}//create table- (void)createTable{    char *errorMsg;    const char *createSql="create table if not exists persons (id integer primary key autoincrement,name text)";        if (sqlite3_exec(database, createSql, NULL, NULL, &errorMsg)==SQLITE_OK)    {        NSLog(@"create ok.");    }    else    {        NSLog( @"can not create table" );        [self ErrorReport:[NSString stringWithFormat:@"%s",createSql]];    }}//insert table- (void)insertTable{    char *errorMsg;        const char *insertSql="insert into persons (name) values ('skyming')";    if (sqlite3_exec(database, insertSql, NULL, NULL, &errorMsg)==SQLITE_OK)    {        NSLog(@"insert ok.");    }    else    {        NSLog( @"can not insert it to table" );        [self ErrorReport:[NSString stringWithFormat:@"%s",insertSql]];    }}//query table- (void)queryTable{    const char *selectSql="select id,name from persons";    sqlite3_stmt *statement;    if (sqlite3_prepare_v2(database, selectSql, -1, &statement, nil)==SQLITE_OK)    {        NSLog(@"select ok.");        while (sqlite3_step(statement)==SQLITE_ROW)//SQLITE_OK SQLITE_ROW        {            int _id=sqlite3_column_int(statement, 0);            NSString *name=[[NSString alloc] initWithCString:(char *)sqlite3_column_text(statement, 1) encoding:NSUTF8StringEncoding];            NSLog(@"row>>id %i, name>> %@",_id,name);        }            }    else    {        //error        [self ErrorReport:[NSString stringWithFormat:@"%s",selectSql]];    }        sqlite3_finalize(statement);}//delete table- (void)deleteTable{    char *errorMsg;    [self openDataBase];        const char *sql = "DELETE FROM persons where id=24";    if (sqlite3_exec(database, sql, NULL, NULL, &errorMsg)==SQLITE_OK)    {        NSLog(@"delete ok.");    }    else    {        NSLog( @"can not delete it" );        [self ErrorReport:[NSString stringWithFormat:@"%s",sql]];    }    }//error- (void)ErrorReport: (NSString *)item{    char *errorMsg;        if (sqlite3_exec(database, [item cStringUsingEncoding:NSUTF8StringEncoding], NULL, NULL, &errorMsg)==SQLITE_OK)    {        NSLog(@"%@ ok.",item);    }    else    {        NSLog(@"error: %s",errorMsg);        sqlite3_free(errorMsg);    }}