1.Realm
2.GYDataCenter
3.CoreData
4.FMDB
每個都有優(yōu)劣之分，但是現(xiàn)在比較火的應(yīng)用是Realm .
FMDB:
將數(shù)據(jù)緩存進(jìn)數(shù)據(jù)庫：
注意：任何對象都要實(shí)現(xiàn)NSCodeing協(xié)議才能實(shí)現(xiàn)轉(zhuǎn)為NSData
(一般已經(jīng)實(shí)現(xiàn)，但是自定義的類需實(shí)現(xiàn)其相應(yīng)的方法)
1>工具類
2>導(dǎo)入工具類#import"FMDB.h"
3>靜態(tài)
4>initialize打開數(shù)據(jù)庫
+ (void)initialize
{
//1.打開數(shù)據(jù)庫
NSString*path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)lastObject]stringByAppendingPathComponent:@"statuses.sqlite"];
_db= [FMDatabasedatabaseWithPath:path];
[_dbopen];
//2.創(chuàng)表
[_dbexecuteUpdate:@"CREATE TABLE IF NOT EXISTS t_status
(id integer PRIMARY KEY, status blob NOT NULL, idstr text NOT NULL);"];
}
/*
*數(shù)據(jù)庫中存入數(shù)據(jù)
*/
+ (void)saveStatuses:(NSArray*)statuses
{
//要將一個對象存進(jìn)數(shù)據(jù)庫的blob字段,最好先轉(zhuǎn)為NSData
//一個對象要遵守NSCoding協(xié)議,實(shí)現(xiàn)協(xié)議中相應(yīng)的方法,才能轉(zhuǎn)成NSData
for(NSDictionary*statusinstatuses) {
//NSDictionary --> NSData
NSData*statusData = [NSKeyedArchiverarchivedDataWithRootObject:status];
[_dbexecuteUpdateWithFormat:@"INSERT
INTO t_status(status, idstr) VALUES (%@, %@);", statusData, status[@"idstr"]];
}
}
+ (NSArray*)statusesWithParams:(NSDictionary*)params
{
//根據(jù)請求參數(shù)生成對應(yīng)的查詢SQL語句
NSString*sql =nil;
if(params[@"since_id"]) {
sql = [NSStringstringWithFormat:@"SELECT
* FROM t_status WHERE idstr > %@ ORDER BY idstr DESC LIMIT 20;", params[@"since_id"]];
}elseif(params[@"max_id"]) {
sql = [NSStringstringWithFormat:@"SELECT
* FROM t_status WHERE idstr <= %@ ORDER BY idstr DESC LIMIT 20;", params[@"max_id"]];
}else{
sql =@"SELECT * FROM t_status ORDER BY idstr DESC LIMIT
20;";
}
//執(zhí)行SQL遍歷最后的結(jié)果
FMResultSet*set = [_dbexecuteQuery:sql];
NSMutableArray*statuses = [NSMutableArrayarray];
while(set.next) {
NSData*statusData = [setobjectForColumnName:@"status"];
NSDictionary*status = [NSKeyedUnarchiverunarchiveObjectWithData:statusData];
[statusesaddObject:status];
}
returnstatuses;
}
NSCoding實(shí)現(xiàn)方法
.h文件
@interfaceHMShop :NSObject
.m文件
- (void)encodeWithCoder:(NSCoder*)encoder
{
[encoderencodeObject:self.nameforKey:@"name"];
[encoderencodeDouble:self.priceforKey:@"price"];
}
- (id)initWithCoder:(NSCoder*)decoder
{
if(self= [superinit]) {
self.name=
[decoderdecodeObjectForKey:@"name"];
self.price=
[decoderdecodeDoubleForKey:@"price"];
}
returnself;
}
/**NSLog*/
- (NSString*)description
{
return[NSStringstringWithFormat:@"%@
<-> %f",self.name,self.price];
}
未完.....
