FMDB puts objects into the database, and fmdb Object Database

FMDB puts objects into the database, and fmdb Object Database

First, create an HJShop class to implement the NSCoding protocol.

# Import <Foundation/Foundation. h>

@ Interface HJShop: NSObject <NSCoding>

@ Property (nonatomic, copy) NSString * name;

@ Property (nonatomic, assign) double price;

@ End

# Import "HJShop. h"

@ Implementation HJShop

-(Void) encodeWithCoder :( NSCoder *) ACO

{

[Ecoder encodeObject: self. name forKey: @ "name"];

[Ecoder encodeDouble: self. price forKey: @ "price"];

}

-(Id) initWithCoder :( NSCoder *) aDecoder

{

If (self = [super init]) {

Self. name = [aDecoder decodeObjectForKey: @ "name"];

Self. price = [aDecoder decodeDoubleForKey: @ "price"];

}

Return self;

}

-(NSString *) description

{

Return [NSString stringWithFormat: @ "% @-% f", self. name, self. price];

}

@ End

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Then use the FMDB framework

// Initialization

NSString * path = [[NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent: @ "shop. sqlite"];

Self. db = [FMDatabase databaseWithPath: path];

[Self. db open];

// Create a table

[Self. db executeUpdate: @ "create table if not exists t_shop (id integer primary key, shop blob not null unique);"];

[Self addShops];

[Self readShop];

 

-(Void) addShops

{

HJShop * shop = [[HJShop alloc] init];

Shop. name = @ "jack ";

Shop. price = 11.0;

NSData * data = [NSKeyedArchiver archivedDataWithRootObject: shop];

[Self. db executeUpdateWithFormat: @ "insert or ignore into t_shop (shop) VALUES (% @);", data];

}

-(Void) readShop

{

FMResultSet * set = [self. db executeQuery: @ "SELECT * FROM t_shop;"];

While (set. next ){

NSData * data = [set objectForColumnName: @ "shop"];

HJShop * shop = [NSKeyedUnarchiver unarchiveObjectWithData: data];

NSLog (@ "% @", shop );

}

}

As long as the object encoding is converted into a binary file, it can be put into SQLite.