对于简单的数据，您应该使用NSUserDefaults。CoreData非常酷，但主要用于存储数据库结构，并引入了复杂性（但我喜欢它：））。如果您只需要存储字符串、数组等数据（基本上是偏好设置），则可以使用NSUserDefaults：
例如：
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; //load NSUserDefaults
NSArray *fakeFavs = [[ NSArray alloc] initWithObjects:@"2",@"4", @"100", nil]; //declare array to be stored in NSUserDefaults
[prefs setObject:fakeFavs forKey:@"favourites"]; //set the prev Array for key value "favourites"
prefs的NSUserDefaults实例，用于访问应用程序的持久性数据存储。 NSMutableArray *favorites = [prefs arrayForKey:@"favourites"];这行代码使用prefs实例从存储中获取一个名为“favourites”的数组，并将其分配给favorites可变数组。 - Sr.RichieNSUserDefaults *prefs = [NSUserDefaults standardUserDefaults]; NSMutableArray *favorites = [[prefs arrayForKey:@"favourites"] mutableCopy]; - DigitalNinja存储数据有两个基本的选择：
CoreData使用SQLite，其API稍微更容易使用（您不需要了解SQL或编写大量函数来读取和写入您的数据）。
SQLite API仍然是一个很好的选择，因为它使用SQLite的C API，这非常好地记录并且易于使用。使用该选项可以将其针对旧版的iOS平台。
无论哪种选择，数据都将在客户端存储，并且每次用户通过iTunes同步手机时都会进行备份。
[NSUserDefaults standardUserDefaults]
您有几种不同的方式可以在iPhone上存储应用程序数据。
// Create Database file
- (void)createEditableCopyOfDatabaseIfNeeded
{
// First, test for existence.
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSLog(@"%@",documentsDirectory);
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"TestDB.sqlite"];
success = [fileManager fileExistsAtPath:writableDBPath];
if (success) return;
// The writable database does not exist, so copy the default to the appropriate location.
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"TestDB.sqlite"];
success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
if (!success) {
NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]);
}
}
Select Query::::::
NSArray *array_hiback =[app.sk lookupAllForSQL:@"SELECT * FROM cycle_datagathering_begoodyourselef ORDER BY RANDOM() LIMIT 1"];
NSLog(@"%@",array_hiback);
insert Query:::::
NSMutableDictionary *dict=[[NSMutableDictionary alloc]init];
[dict setObject:@"0" forKey:@"isuploaded"];
[app.sk insertDictionary:dict forTable:@"mindeditor"];
[dict release];
update Query::::
NSMutableDictionary *updatedata=[[NSMutableDictionary alloc]init];
[updatedata setObject: [[NSUserDefaults standardUserDefaults] objectForKey:@"savecycleid"] forKey:@"cycleid"];
delete Query:::::
[app.sk deleteWhere:[NSString stringWithFormat:@"rowid=%@",str] forTable:@"mindeditor"];
[app.sk updateDictionary:updatedata forTable:@"mindeditor" where:[NSString stringWithFormat:@"rowid=%@", [[checkarray objectAtIndex:checkarray.count-1] objectForKey:@"cycleid"]]];
[updatedata release];
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
sk = [[SKDatabase alloc] init];
NSString *db = @"MindEditor.db";
[sk initWithDynamicFile:db];
userid=@"0";
}
SKDatabase.h
//
// SKDatabase.h
// Version 1.1
//
// Created by Shannon Appelcline on 9/11/08.
// Copyright 2008 __MyCompanyName__. All rights reserved.
//
#import <UIKit/UIKit.h>
#import <sqlite3.h>
@protocol SKDatabaseDelegate <NSObject>
@optional
- (void)databaseTableWasUpdated:(NSString *)table;
@end
@interface SKDatabase : NSObject {
id<SKDatabaseDelegate> delegate;
sqlite3 *dbh;
BOOL dynamic;
}
@property (assign) id<SKDatabaseDelegate> delegate;
@property sqlite3 *dbh;
@property BOOL dynamic;
- (id)initWithFile:(NSString *)dbFile;
- (id)initWithDynamicFile:(NSString *)dbFile;
- (void)close;
- (sqlite3_stmt *)prepare:(NSString *)sql;
- (id)lookupColForSQL:(NSString *)sql;
- (NSDictionary *)lookupRowForSQL:(NSString *)sql;
- (NSArray *)lookupAllForSQL:(NSString *)sql;
- (int)lookupCountWhere:(NSString *)where forTable:(NSString *)table;
- (int)lookupMax:(NSString *)key Where:(NSString *)where forTable:(NSString *)table;
- (int)lookupSum:(NSString *)key Where:(NSString *)where forTable:(NSString *)table;
- (void)insertArray:(NSArray *)dbData forTable:(NSString *)table;
- (void)insertDictionary:(NSDictionary *)dbData forTable:(NSString *)table;
- (void)updateArray:(NSArray *)dbData forTable:(NSString *)table;
- (void)updateArray:(NSArray *)dbData forTable:(NSString *)table where:(NSString *)where;
- (void)updateDictionary:(NSDictionary *)dbData forTable:(NSString *)table;
- (void)updateDictionary:(NSDictionary *)dbData forTable:(NSString *)table where:(NSString *)where;
- (void)updateSQL:(NSString *)sql forTable:(NSString *)table;
- (void)deleteWhere:(NSString *)where forTable:(NSString *)table;
- (BOOL)runDynamicSQL:(NSString *)sql forTable:(NSString *)table;
@end
SKDatabase.m
//
// SKDatabase.m
// Version 1.1
//
// Created by Shannon Appelcline on 9/11/08.
// Copyright 2008 __MyCompanyName__. All rights reserved.
//
#import "SKDatabase.h"
@implementation SKDatabase
@synthesize delegate;
@synthesize dbh;
@synthesize dynamic;
// Two ways to init: one if you're just SELECTing from a database, one if you're UPDATing
// and or INSERTing
- (id)initWithFile:(NSString *)dbFile {
if (self = [super init]) {
NSString *paths = [[NSBundle mainBundle] resourcePath];
NSString *path = [paths stringByAppendingPathComponent:dbFile];
int result = sqlite3_open([path UTF8String], &dbh);
NSAssert1(SQLITE_OK == result, NSLocalizedStringFromTable(@"Unable to open the sqlite database (%@).", @"Database", @""), [NSString stringWithUTF8String:sqlite3_errmsg(dbh)]);
self.dynamic = NO;
}
return self;
}
- (id)initWithDynamicFile:(NSString *)dbFile {
if (self = [super init]) {
NSArray *docPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docDir = [docPaths objectAtIndex:0];
NSString *docPath = [docDir stringByAppendingPathComponent:dbFile];
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath:docPath]) {
NSString *origPaths = [[NSBundle mainBundle] resourcePath];
NSString *origPath = [origPaths stringByAppendingPathComponent:dbFile];
NSError *error;
int success = [fileManager copyItemAtPath:origPath toPath:docPath error:&error];
NSAssert1(success,[NSString stringWithString:@"Failed to copy database into dynamic location"],error);
}
int result = sqlite3_open([docPath UTF8String], &dbh);
NSAssert1(SQLITE_OK == result, NSLocalizedStringFromTable(@"Unable to open the sqlite database (%@).", @"Database", @""), [NSString stringWithUTF8String:sqlite3_errmsg(dbh)]);
self.dynamic = YES;
}
return self;
}
// Users should never need to call prepare
- (sqlite3_stmt *)prepare:(NSString *)sql {
const char *utfsql = [sql UTF8String];
sqlite3_stmt *statement;
if (sqlite3_prepare([self dbh],utfsql,-1,&statement,NULL) == SQLITE_OK) {
return statement;
} else {
return 0;
}
}
// Three ways to lookup results: for a variable number of responses, for a full row
// of responses, or for a singular bit of data
- (NSArray *)lookupAllForSQL:(NSString *)sql {
sqlite3_stmt *statement;
id result;
NSMutableArray *thisArray = [NSMutableArray arrayWithCapacity:4];
if (statement = [self prepare:sql]) {
while (sqlite3_step(statement) == SQLITE_ROW) {
NSMutableDictionary *thisDict = [NSMutableDictionary dictionaryWithCapacity:4];
for (int i = 0 ; i < sqlite3_column_count(statement) ; i++)
{
if (sqlite3_column_decltype(statement,i) != NULL &&
strcasecmp(sqlite3_column_decltype(statement,i),"Boolean") == 0)
{
result = [NSNumber numberWithBool:(BOOL)sqlite3_column_int(statement,i)];
}
else if (sqlite3_column_type(statement, i) == SQLITE_TEXT)
{
result = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement,i)];
}
else if
(sqlite3_column_type(statement,i) == SQLITE_INTEGER)
{
result = [NSNumber numberWithInt:(int)sqlite3_column_int(statement,i)];
}
else if (sqlite3_column_type(statement,i) == SQLITE_FLOAT)
{
result = [NSNumber numberWithFloat:(float)sqlite3_column_double(statement,i)];
}
else
{
result = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement,i)];
}
if (result)
{
[thisDict setObject:result
forKey:[NSString stringWithUTF8String:sqlite3_column_name(statement,i)]];
}
}
[thisArray addObject:[NSDictionary dictionaryWithDictionary:thisDict]];
[thisArray retain];
}
}
sqlite3_finalize(statement);
return thisArray;
}
- (NSDictionary *)lookupRowForSQL:(NSString *)sql {
sqlite3_stmt *statement;
id result;
NSMutableDictionary *thisDict = [NSMutableDictionary dictionaryWithCapacity:4];
if (statement = [self prepare:sql])
{
if (sqlite3_step(statement) == SQLITE_ROW)
{
for (int i = 0 ; i < sqlite3_column_count(statement) ; i++)
{
if (strcasecmp(sqlite3_column_decltype(statement,i),"Boolean") == 0)
{
result = [NSNumber numberWithBool:(BOOL)sqlite3_column_int(statement,i)];
}
else if (sqlite3_column_type(statement, i) == SQLITE_TEXT)
{
result = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement,i)];
}
else if (sqlite3_column_type(statement,i) == SQLITE_INTEGER)
{
result = [NSNumber numberWithInt:(int)sqlite3_column_int(statement,i)];
}
else if (sqlite3_column_type(statement,i) == SQLITE_FLOAT)
{
result = [NSNumber numberWithFloat:(float)sqlite3_column_double(statement,i)];
}
else
{
result = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement,i)];
}
if (result)
{
[thisDict setObject:result
forKey:[NSString stringWithUTF8String:sqlite3_column_name(statement,i)]];
}
}
}
}
sqlite3_finalize(statement);
return thisDict;
}
- (id)lookupColForSQL:(NSString *)sql {
sqlite3_stmt *statement;
id result;
if (statement = [self prepare:sql]) {
if (sqlite3_step(statement) == SQLITE_ROW) {
if (strcasecmp(sqlite3_column_decltype(statement,0),"Boolean") == 0) {
result = [NSNumber numberWithBool:(BOOL)sqlite3_column_int(statement,0)];
} else if (sqlite3_column_type(statement, 0) == SQLITE_TEXT) {
result = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement,0)];
} else if (sqlite3_column_type(statement,0) == SQLITE_INTEGER) {
result = [NSNumber numberWithInt:(int)sqlite3_column_int(statement,0)];
} else if (sqlite3_column_type(statement,0) == SQLITE_FLOAT) {
result = [NSNumber numberWithDouble:(double)sqlite3_column_double(statement,0)];
} else {
result = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement,0)];
}
}
}
sqlite3_finalize(statement);
return result;
}
// Simple use of COUNTS, MAX, etc.
- (int)lookupCountWhere:(NSString *)where forTable:(NSString *)table {
int tableCount = 0;
NSString *sql = [NSString stringWithFormat:@"SELECT COUNT(*) FROM %@ WHERE %@",
table,where];
sqlite3_stmt *statement;
if (statement = [self prepare:sql]) {
if (sqlite3_step(statement) == SQLITE_ROW) {
tableCount = sqlite3_column_int(statement,0);
}
}
sqlite3_finalize(statement);
return tableCount;
}
- (int)lookupMax:(NSString *)key Where:(NSString *)where forTable:(NSString *)table {
int tableMax = 0;
NSString *sql = [NSString stringWithFormat:@"SELECT MAX(%@) FROM %@ WHERE %@",
key,table,where];
sqlite3_stmt *statement;
if (statement = [self prepare:sql]) {
if (sqlite3_step(statement) == SQLITE_ROW) {
tableMax = sqlite3_column_int(statement,0);
}
}
sqlite3_finalize(statement);
return tableMax;
}
- (int)lookupSum:(NSString *)key Where:(NSString *)where forTable:(NSString *)table {
int tableSum = 0;
NSString *sql = [NSString stringWithFormat:@"SELECT SUM(%@) FROM %@ WHERE %@",
key,table,where];
sqlite3_stmt *statement;
if (statement = [self prepare:sql]) {
if (sqlite3_step(statement) == SQLITE_ROW) {
tableSum = sqlite3_column_int(statement,0);
}
}
sqlite3_finalize(statement);
return tableSum;
}
// INSERTing and UPDATing
- (void)insertArray:(NSArray *)dbData forTable:(NSString *)table {
// NSMutableString *sql = [NSMutableString stringWithCapacity:16];
// [sql appendFormat:@"INSERT INTO %@ (",table];
//
//
// for (int i = 0 ; i < [dbData count] ; i++) {
// NSLog(@"%@",[[dbData objectAtIndex:i] objectForKey:@"mid"]);
// [sql appendFormat:@"%@",[[dbData objectAtIndex:i] objectForKey:@"key"]];
// if (i + 1 < [dbData count]) {
// [sql appendFormat:@", "];
// }
// }
// [sql appendFormat:@") VALUES("];
// for (int i = 0 ; i < [dbData count] ; i++) {
// if ([[[dbData objectAtIndex:i] objectForKey:@"value"] intValue]) {
// [sql appendFormat:@"%@",[[[dbData objectAtIndex:i] objectForKey:@"value"] intValue]];
// } else {
// [sql appendFormat:@"'%@'",[[dbData objectAtIndex:i] objectForKey:@"value"]];
// }
// if (i + 1 < [dbData count]) {
// [sql appendFormat:@", "];
// }
// }
// [sql appendFormat:@")"];
// [self runDynamicSQL:sql forTable:table];
for(int i=0;i<[dbData count];i++)
{
NSDictionary *dict=[dbData objectAtIndex:i];
NSMutableString *sql = [NSMutableString stringWithCapacity:16];
[sql appendFormat:@"INSERT INTO %@ (",table];
NSArray *dataKeys = [dict allKeys];
for (int i = 0 ; i < [dataKeys count] ; i++) {
[sql appendFormat:@"%@",[dataKeys objectAtIndex:i]];
if (i + 1 < [dataKeys count]) {
[sql appendFormat:@", "];
}
}
[sql appendFormat:@") VALUES("];
for (int i = 0 ; i < [dataKeys count] ; i++) {
if ([[dict objectForKey:[dataKeys objectAtIndex:i]] intValue]) {
[sql appendFormat:@"%@",[dict objectForKey:[dataKeys objectAtIndex:i]]];
} else {
[sql appendFormat:@"'%@'",[dict objectForKey:[dataKeys objectAtIndex:i]]];
}
if (i + 1 < [dict count]) {
[sql appendFormat:@", "];
}
}
[sql appendFormat:@")"];
[self runDynamicSQL:sql forTable:table];
}
}
- (void)insertDictionary:(NSDictionary *)dbData forTable:(NSString *)table {
NSMutableString *sql = [NSMutableString stringWithCapacity:16];
[sql appendFormat:@"INSERT INTO %@ (",table];
NSArray *dataKeys = [dbData allKeys];
for (int i = 0 ; i < [dataKeys count] ; i++) {
[sql appendFormat:@"%@",[dataKeys objectAtIndex:i]];
if (i + 1 < [dbData count]) {
[sql appendFormat:@", "];
}
}
[sql appendFormat:@") VALUES("];
for (int i = 0 ; i < [dataKeys count] ; i++) {
//if ([[dbData objectForKey:[dataKeys objectAtIndex:i]] intValue]) {
// [sql appendFormat:@"%@",[dbData objectForKey:[dataKeys objectAtIndex:i]]];
// } else {
[sql appendFormat:@"'%@'",[dbData objectForKey:[dataKeys objectAtIndex:i]]];
//}
if (i + 1 < [dbData count]) {
[sql appendFormat:@", "];
}
}
[sql appendFormat:@")"];
[self runDynamicSQL:sql forTable:table];
}
- (void)updateArray:(NSArray *)dbData forTable:(NSString *)table {
[self updateArray:dbData forTable:table where:NULL];
}
- (void)updateArray:(NSArray *)dbData forTable:(NSString *)table where:(NSString *)where {
NSMutableString *sql = [NSMutableString stringWithCapacity:16];
[sql appendFormat:@"UPDATE %@ SET ",table];
for (int i = 0 ; i < [dbData count] ; i++) {
if ([[[dbData objectAtIndex:i] objectForKey:@"value"] intValue]) {
[sql appendFormat:@"%@=%@",
[[dbData objectAtIndex:i] objectForKey:@"key"],
[[dbData objectAtIndex:i] objectForKey:@"value"]];
} else {
[sql appendFormat:@"%@='%@'",
[[dbData objectAtIndex:i] objectForKey:@"key"],
[[dbData objectAtIndex:i] objectForKey:@"value"]];
}
if (i + 1 < [dbData count]) {
[sql appendFormat:@", "];
}
}
if (where != NULL) {
[sql appendFormat:@" WHERE %@",where];
} else {
[sql appendFormat:@" WHERE 1",where];
}
[self runDynamicSQL:sql forTable:table];
}
- (void)updateDictionary:(NSDictionary *)dbData forTable:(NSString *)table {
[self updateDictionary:dbData forTable:table where:NULL];
}
- (void)updateDictionary:(NSDictionary *)dbData forTable:(NSString *)table where:(NSString *)where {
NSMutableString *sql = [NSMutableString stringWithCapacity:16];
[sql appendFormat:@"UPDATE %@ SET ",table];
NSArray *dataKeys = [dbData allKeys];
for (int i = 0 ; i < [dataKeys count] ; i++) {
if ([[dbData objectForKey:[dataKeys objectAtIndex:i]] intValue]) {
[sql appendFormat:@"%@=%@",
[dataKeys objectAtIndex:i],
[dbData objectForKey:[dataKeys objectAtIndex:i]]];
} else {
[sql appendFormat:@"%@='%@'",
[dataKeys objectAtIndex:i],
[dbData objectForKey:[dataKeys objectAtIndex:i]]];
}
if (i + 1 < [dbData count]) {
[sql appendFormat:@", "];
}
}
if (where != NULL) {
[sql appendFormat:@" WHERE %@",where];
}
[self runDynamicSQL:sql forTable:table];
}
- (void)updateSQL:(NSString *)sql forTable:(NSString *)table {
[self runDynamicSQL:sql forTable:table];
}
- (void)deleteWhere:(NSString *)where forTable:(NSString *)table {
NSString *sql = [NSString stringWithFormat:@"DELETE FROM %@ WHERE %@",
table,where];
[self runDynamicSQL:sql forTable:table];
}
// INSERT/UPDATE/DELETE Subroutines
- (BOOL)runDynamicSQL:(NSString *)sql forTable:(NSString *)table {
int result;
//NSAssert1(self.dynamic == 1,[NSString stringWithString:@"Tried to use a dynamic function on a static database"],NULL);
sqlite3_stmt *statement;
if (statement = [self prepare:sql]) {
result = sqlite3_step(statement);
}
sqlite3_finalize(statement);
if (result) {
if (self.delegate != NULL && [self.delegate respondsToSelector:@selector(databaseTableWasUpdated:)]) {
[delegate databaseTableWasUpdated:table];
}
return YES;
} else {
return NO;
}
}
// requirements for closing things down
- (void)dealloc {
[self close];
[delegate release];
[super dealloc];
}
- (void)close {
if (dbh) {
sqlite3_close(dbh);
}
}
@end