本文主要是介绍iOS sqllite 数据库，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
前言：现在的项目中 推送消息需要用到 数据库缓存从服务器推送过来的消息，demo代码如下：
//
// MessageTool.m
// testdataBase
//
// Created by tinghou on 16/7/28.
// Copyright © 2016年 tinghou. All rights reserved.
//#import "MessageTool.h"
#import "FMDB.h"
@implementation MessageTool
static FMDatabase *_db;
+ (void)initialize
{// NSCachesDirectory NSDocumentDirectoryNSString *path = [[NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"messages.sqlite"];_db = [FMDatabase databaseWithPath:path];[_db open];DLog(@"path = %@",path);// [_db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_message (id integer PRIMARY KEY, message blob NOT NULL);"];[_db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_message (id integer PRIMARY KEY, message blob NOT NULL);"];
}+ (NSMutableArray *)messagesWithParams:(NSDictionary *)params
{NSString *sql = nil;sql = @"SELECT * FROM t_message;";FMResultSet *set = [_db executeQuery:sql];NSMutableArray *messages = [NSMutableArray array];while (set.next) {int ID = [set intForColumn:@"id"];DLog(@"ID = %d",ID);NSData *Data = [set objectForColumnName:@"message"];
// NSString *isRead = [set objectForColumnName:@"isRead"];
// NSString *isRead = [NSKeyedUnarchiver unarchiveObjectWithData:isReadData];NSDictionary *messageDic = [NSKeyedUnarchiver unarchiveObjectWithData:Data];
// NSDictionary *dic = @{@"messageDic":messageDic,
// @"isRead":isRead
// };[messages addObject:messageDic];}return messages;
}
//删除
+(void)delete
{if ([_db open]) {NSString *deleteSql = [NSString stringWithFormat:@"DELETE FROM t_message;"];BOOL res = [_db executeUpdate:deleteSql];if (!res) {NSLog(@"error when delete db table");} else {NSLog(@"success to delete db table");}
// [_db close];}
}
+ (void)resaveMessages:(NSMutableArray *)messages{for (NSDictionary *message in messages) {NSData *messageData = [NSKeyedArchiver archivedDataWithRootObject:message];[_db executeUpdateWithFormat:@"INSERT INTO t_message(message) VALUES ( %@);", messageData];}
}+ (void)saveMessages:(NSMutableArray *)messages
{for (NSDictionary *message in messages) {
// NSString *isRead = @"0";NSData *messageData = [NSKeyedArchiver archivedDataWithRootObject:message];[_db executeUpdateWithFormat:@"INSERT INTO t_message(message) VALUES ( %@);", messageData];}
}@end
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