没用FMDB封装SQLite

打开和关闭数据库

执行sql语句

//内部状态判断
1._db是否可用
2.sql语句是否是合法状态
//解析参数
va_list args;
va_start(args,sql);
/*获取有多少个参数需要绑定*/
NSArray *bindArgs = [self parseArguments:args];
va_end(args);

//绑定参数
通过bindObject 这个自定义的方法，对传过来的参数进行绑定

FMDB封装的SQLite

https://github.com/ccgus/fmdb

demo

FMDB要求我们每一个传进去的参数都是一个objc对象

• 返回的路径操作

- (NSString *)filepath
{
    NSString *documents = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
    return  [documents stringByAppendingPathComponent:@"contacts.db"];
}

• 打开数据库操作

- (void)openDatabase
{
    NSString *filepath = [self filepath];
    _database = [FMDatabase databaseWithPath:filepath];
    if ([_database open])
    {
        if (![_database executeUpdate:@"create table if not exists contacts(id integer primary key autoincrement,name text,mobile text)"])
        {
            NSLog(@"open database failed");
        }
    }
    else
    {
        NSLog(@"open database failed");
    }
}

• 关闭数据库操作

- (void)dealloc
{
    [_database close];
}

• 读取数据库操作

- (void)read
{
  FMResultSet *set=  [_database executeQuery:@"select *from contacts"];
    while ([set next]) {
        Contact *contact=[[Contact alloc]init];
        contact.serialId=[set unsignedLongLongIntForColumn:@"id"];
        contact.name=[set stringForColumn:@"name"];
        contact.mobile=[set stringForColumn:@"mobile"];
        [self.contacts addObject:contact];
    }
    [set close];
}

• 从数据库删除数据操作

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete)
    {
        NSInteger index = [indexPath row];
        int64_t serialId = [self.contacts[index] serialId];
        
        if ([_database executeUpdate:@"delete from contacts where id = ?",@(serialId)])
        {
            [self.contacts removeObjectAtIndex:index];
            [self.tableView reloadData];
        }
    }
}

从数据库搜索操作

- (void)updateSearchResultsForSearchController:(UISearchController *)searchController
{
    NSString *text = searchController.searchBar.text;
    NSMutableArray *contacts = nil;
    if ([text length])
    {
        NSString *searchText = [NSString stringWithFormat:@"%%%@%%",text];
        contacts = [NSMutableArray array];
        NSString *sql = @"select * from contacts where name like ? or mobile like ?";
        
        FMResultSet *set = [_database executeQuery:sql,searchText,searchText];
        while ([set next])
        {
            Contact *contact =[[Contact alloc] init];
            contact.serialId = [set longLongIntForColumn:@"id"];
            contact.name = [set stringForColumn:@"name"];
            contact.mobile = [set stringForColumn:@"mobile"];
            [contacts addObject:contact];
        }
        [set close];
    }

    self.filteredContacts = contacts;
    [self.tableView reloadData];
}