Ios_sn_coredate (i) package use

Read a package CoreData article is very good, there is a basic use of encapsulation, but did not write how with TableView, I use the process of some small twists and turns, I did a demo, we can see the source of some basic use should not be difficult,

Original: Http://blog.csdn.net/pengyuan_d/article/details/40657225?utm_source=tuicool&utm_medium=referral

(1) Create a data model file named Mymodel.xcdatamodeld

(2) Create the Users table, add fields

(3) Create Nsmanagedobject Subclass table entity file

(4) in the users.m file, overwrite the description method

CoreDataDBHelper.h #import <Foundation/Foundation.h> #import <CoreData/CoreData.h>//path of local file storage #define P ATH [Nshomedirectory () stringbyappendingpathcomponent:@ "documents/sqlite.db"] #define MODEL_NAME @ "MyModel" @interfa            Ce coredatadbhelper:nsobject {//1. Data model object Nsmanagedobjectmodel *_managedobjectmodel;            2. Create a local persistent file object Nspersistentstorecoordinator *_persistentstorecoordinator;  3. Manage Data Objects Nsmanagedobjectcontext *_managedobjectcontext;    }//Designed as a single case mode + (Coredatadbhelper *) Sharecoredatadbhelper;    Method of adding data-(BOOL) Insertdatawithmodelname: (NSString *) modelname setattributwithdic: (nsdictionary *) params;           View/* ModelName: Entity object class name predicatestring: Predicate condition identifers: Sort Field Collection Ascending : Whether ascending */-(Nsarray *) Selectdatawithmodelname: (NSString *) modelname predicatestring: (NSS Tring *) predicatestring SorT: (Nsarray *) identifers Ascending: (BOOL) ascending;               Modified-(BOOL) Updatedatawithmodelname: (NSString *) modelname predicatestring: (NSString *) predicatestring    Setattributwithdic: (nsdictionary *) params;     Delete-(BOOL) Deletedatawithmodelname: (NSString *) modelname predicatestring: (NSString *) predicatestring;   @end

COREDATADBHELPER.M

  #import "CoreDataDBHelper.h" @implementation Coredatadbhelper-(instancetype) init {self = [super init]; if (self) {///1. Data Model object Nsurl *modelurl = [[NSBundle Mainbundle] Urlforresource:model_name with          extension:@ "MOMD"];                    _managedobjectmodel = [[Nsmanagedobjectmodel alloc] initwithcontentsofurl:modelurl]; 2. Create a local persistent file object _persistentstorecoordinator = [[Nspersistentstorecoordinator alloc] Initwithmanagedobjectmodel:_m          Anagedobjectmodel];                    Set save location for local data nsurl *fileurl = [Nsurl Fileurlwithpath:path]; [_persistentstorecoordinator addpersistentstorewithtype:nssqlitestoretype configuration:nil URL:fileUrl options:                    Nil Error:nil];          3. Manage Data Objects _managedobjectcontext = [[Nsmanagedobjectcontext alloc] init];      [_managedobjectcontext Setpersistentstorecoordinator:_persistentstorecoordinator];  } return self; }//Designed as a singleton mode + (COREDATADBHELper *) sharecoredatadbhelper {static Coredatadbhelper *coredatadbhelper = nil;      Static dispatch_once_t Oncetoken;      Dispatch_once (&oncetoken, ^{coredatadbhelper = [[Coredatadbhelper alloc] init];            });  return coredatadbhelper; }//method to add data */params: @{@ "name": @ "Zhang San" @ "Age": @20} */-( BOOL) Insertdatawithmodelname: (NSString *) modelname setattributwithdic: (nsdictionary *) params {nsentit Ydescription *entity = [Nsentitydescription insertnewobjectforentityforname:modelname inManagedObjectContext:_            Managedobjectcontext];          Traversal parameter dictionary for (NSString *key in params) {SEL selector = [self selwithkeyname:key]; if ([entity Respondstoselector:selector]) {[Entity Performselector:selector Withobject:params[key]]          ;            }} [_managedobjectcontext insertobject:entity]; Save to local return [_manaGedobjectcontext Save:nil];           }//View/* ModelName: Entity object class name predicatestring: Predicate condition identifers: Sort Field Collection Ascending : Whether ascending */-(Nsarray *) Selectdatawithmodelname: (NSString *) modelname predicatestring: (NSString *) p Redicatestring Sort: (Nsarray *) identifers Ascending: (BOOL) ASC Ending {//1. Create entity object Nsentitydescription *entity = [Nsentitydescription entityforname:modelname inmanagedobject            Context:_managedobjectcontext];      2. Create a Query object nsfetchrequest *request = [[Nsfetchrequest alloc] init];            Tell the Query object the type of data you want to query [request setentity:entity]; Add Query condition if (predicatestring! = Nil | |      [Predicatestring isequaltostring:@ ""])          {Nspredicate *predicate = [Nspredicate predicatewithformat:predicatestring];      [Request Setpredicate:predicate]; }//3. Set sort Nsmutablearray *sortdescriptors = [NSMUtablearray array]; For (NSString *identifer in identifers) {//Create sort object Nssortdescriptor *sortdescriptor = [[Nssortdesc          Riptor alloc] Initwithkey:identifer ascending:ascending];      Add the Sort object to the array [sortdescriptors Addobject:sortdescriptor];            }//Set the Sort object inside the query object [request Setsortdescriptors:sortdescriptors];  3. Start inquiry return [_managedobjectcontext executefetchrequest:request Error:nil]; }//Modify-(BOOL) Updatedatawithmodelname: (NSString *) modelname predicatestring: (NSString *) predicate String setattributwithdic: (nsdictionary *) params {//Get all required to modify entity object Nsarray *entitys = [Self Selec            Tdatawithmodelname:modelname predicatestring:predicatestring Sort:nil Ascending:no]; Traverse all entity objects for (nsentitydescription *entity in Entitys) {//Modify the properties of the object for (NSString *key in P      Arams) {SEL selector = [self selwithkeyname:key];        if ([entity Respondstoselector:selector]) {[Entity Performselector:selector withobj              Ect:params[key]];        }}} return [_managedobjectcontext Save:nil]; }//Delete-(BOOL) Deletedatawithmodelname: (NSString *) modelname predicatestring: (NSString *) predicatest Ring {//Get all required to modify entity object Nsarray *entitys = [self selectdatawithmodelname:modelname predicatestring:predicatestri            ng Sort:nil Ascending:no]; Traverse all entity objects for (nsentitydescription *entity in Entitys) {//delete object [_managedobjectcontext del                Eteobject:entity];  } return [_managedobjectcontext Save:nil]; }//Back to a set method via a string-(SEL) Selwithkeyname: (NSString *) keyName {nsstring *first = [[KeyName substringtoindex      : 1] uppercasestring];      NSString *end = [KeyName substringfromindex:1]; NSString *selstring = [NSString stringwithformat:@ "set%@%@:", first,end];     Return nsselectorfromstring (selstring);   } @end

Ios_sn_coredata Demo

Ios_sn_coredate (i) package use