sqlite之增删改查--简单的实现iOS收藏夹功能
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使用sqlite可以实现简单的收藏夹功能,不多说直接上代码。
1.首先导入libsqlite3.0.dylib,libz.dylib两个类库
2.封装一个NSObject类型的类去管理 (即写sql语句)
在这个类里首先导入一个头文件和你建好的model类 (实现收藏本质是存model类)
model类只是建立需要的字符串(我只写了.h .m里什么都没写)
#import <Foundation/Foundation.h>
@interface TopicDB :NSObject
@property(nonatomic,retain)NSString *topic_id;
@property(nonatomic,retain)NSString *topic_title;
@property(nonatomic,retain)NSString *topic_name;
@property(nonatomic,retain)NSString *topic_image;
@end
.h里声明相应方法,导入相应头文件
#import<sqlite3.h>
#import "TopicDB.h"//我的那个model类
//创建、关闭数据库以及增删改查
+(void)open;
+ (void)close;
+(void)create;
+ (void)insert:(TopicDB *)mymodel;
+ (void)remove:(TopicDB *)mymodel;
+ (void)update;
+ (NSArray *)select;
#import "DataBaseManager.h"
staticsqlite3 *dbPoint = nil;
@implementation DataBaseManager
+ (void)open
{
if (dbPoint) {
return;
}
NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES)firstObject];
path = [path stringByAppendingPathComponent:@"travel_Topic.rdb"];
NSLog(@"%@", path);
int result = sqlite3_open(path.UTF8String, &dbPoint);
if (result == SQLITE_OK) {
NSLog(@"数据库打开成功");
}
}
+ (void)close
{
sqlite3_close(dbPoint);
}
+ (void)create
{
[selfopen];
NSString *sql =@"create table travel_Topic (title text, name text, image text, id text)";
sqlite3_exec(dbPoint, sql.UTF8String,NULL, NULL,NULL);
}
+ (void)insert:(TopicDB *)mymodel
{
[selfopen];
NSString *sql = [NSStringstringWithFormat:@"insert into travel_Topic values ('%@','%@','%@','%@')", mymodel.topic_title ,mymodel.topic_name, mymodel.topic_image, mymodel.topic_id];
sqlite3_exec(dbPoint, sql.UTF8String,NULL, NULL,NULL);
}
+ (void)remove:(TopicDB *)mymodel
{
[selfopen];
NSString *sql = [NSStringstringWithFormat:@"delete from travel_Topic where title = '%@'",mymodel.topic_title];
sqlite3_exec(dbPoint, sql.UTF8String,NULL, NULL,NULL);
}
+ (void)update
{
[selfcreate];
NSString *sql =@"update travel_Topic set name = '汲国兴250' where number = '250'";
sqlite3_exec(dbPoint, sql.UTF8String,NULL, NULL,NULL);
}
+ (NSArray *)select
{
[selfopen];
//创建数据库替身
sqlite3_stmt *stmt = nil;
NSString *sql =@"select * from travel_Topic";
//执行语句
int result = sqlite3_prepare_v2(dbPoint, sql.UTF8String, -1, &stmt,NULL);
//判断是否成功
if (result == SQLITE_OK) {
//创建数组用来保存查询的数据
NSMutableArray *arr = [NSMutableArrayarray];
//如果还有下一行
while (sqlite3_step(stmt) ==SQLITE_ROW) {
//获取数据
const unsignedchar * topic_title = sqlite3_column_text(stmt, 0);
const unsignedchar * topic_name = sqlite3_column_text(stmt, 1);
const unsignedchar * topic_image = sqlite3_column_text(stmt, 2);
const unsignedchar * topic_id = sqlite3_column_text(stmt, 3);
//封装成model
TopicDB *mymodel = [[TopicDBalloc] init];
mymodel.topic_title = [NSStringstringWithUTF8String:(constchar *) topic_title];
mymodel.topic_name = [NSStringstringWithUTF8String:(constchar *) topic_name];
mymodel.topic_image = [NSStringstringWithUTF8String:(constchar *) topic_image];
mymodel.topic_id = [NSStringstringWithUTF8String:(constchar *) topic_id];
[arraddObject:mymodel];
}
sqlite3_finalize(stmt); //释放数据库替身
return arr;
}
sqlite3_finalize(stmt);
return [NSMutableArrayarray];
}
3.在所需的页面(标签4中的详情页)创建一个收藏按钮,编写一个点击事件的方法(将相应的信息存到model类里)-(void)collectionButton
{
//创建数据库 数据库内同一个表不会叠加 所以放心建。
[DataBaseManagercreate];
//初始化model类存所需数据
TopicDB *model = [[TopicDBalloc]init];
model.topic_title =_str2;
model.topic_name =_str1;
model.topic_image =_str;
model.topic_id = [NSStringstringWithFormat:@"%lu",_Travel_Topic_Sub_Id];
//alert提示框
_alertView = [[UIAlertViewalloc]initWithTitle:@"提示"message:@"已收藏