利用fmdb做了一个简单的本地数据存储，存储对象是字典，首先通过第三方cocospod集成 fmdb (
pod 'FMDB'
)
创建一个新的类继承NSObject，代码如下：
.h
#import <Foundation/Foundation.h>
@interface YMStatusCacheTool : NSObject
/** 存 */
+ (void)ym_saveWithStatus:(NSDictionary *)dataSoucre withParam:(NSString *)house_id;
//取数据
+ (NSDictionary *)ym_statuseWithParam:(NSString *)house_id;
//删
+ (void)ym_deleteWithParam:(NSString *)house_id;
@end
.m
#import "YMStatusCacheTool.h"
#import <FMDB.h>
@implementation YMStatusCacheTool
static FMDatabase * _db;
+ (void)initialize
{
NSString *cachePath = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)[0];
//拼接文件名
NSString *filePath = [cachePath stringByAppendingString:@"status.sqlite"];
//创建了一个数据库实例
_db = [FMDatabase databaseWithPath:filePath];
//打开数据库
if ([_db open]) {
NSLog(@"打开成功");
} else {
NSLog(@"打开失败");
}
//创建表格
BOOL flag = [_db executeUpdate:@"create table if not exists t_status (id integer primary key autoincrement,house_id integer,dict,blob);"];
if (flag) {
NSLog(@"success to creating db table");
} else {
NSLog(@"error when creating db table");
}
}
/** 插入数据 */
+ (void)ym_saveWithStatus:(NSDictionary *)dataSoucre withParam:(NSString *)house_id
{
//打开数据库
if ([_db open]) {
//转为二进制数据
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:dataSoucre];
BOOL flag = [_db executeUpdate:@"insert into t_status (house_id,dict) values(?,?)",house_id,data];
if (flag) {
NSLog(@"插入成功");
} else {
NSLog(@"插入失败");
}
[_db close];
} else {
NSLog(@"打开失败");
}
}
//取数据
+ (NSDictionary *)ym_statuseWithParam:(NSString *)house_id
{
//打开数据库
NSDictionary *dict = [NSDictionary new];
if ([_db open]) {
//查询语句
NSString *sql = [NSString stringWithFormat:@"select * from t_status where house_id = '%@';",house_id];
FMResultSet *set = [_db executeQuery:sql];
while ([set next]) {
NSData *data = [set dataForColumn:@"dict"];
dict = [NSKeyedUnarchiver unarchiveObjectWithData:data];
}
[_db close];
} else {
NSLog(@"打开失败");
}
return dict;
}
//删
+ (void)ym_deleteWithParam:(NSString *)house_id
{
//打开数据库
if ([_db open]) {
//删除语句
NSString *sql = [NSString stringWithFormat:@"delete from t_status where house_id = '%@';",house_id];
BOOL res = [_db executeUpdate:sql];
if (!res) {
NSLog(@"删除失败");
} else {
NSLog(@"删除成功");
}
[_db close];
} else {
NSLog(@"打开失败");
}
}
@end
这个demo没有很好的封装，也没有用上异步线程，缺陷还是蛮大的，当然对于新手也挺合适。