ios - 如何在sqlite数据库的表行中添加NSDictionary

Question

我是iPhone开发的新手。我想在表sqlite行中存储一个NSDictionary。
我用Google搜索，发现了很多结果，但对我不起作用。

这是我的字典:

NSDictionary * dic = [NSDictionary dictionaryWithObjectsAndKeys:@"24",@"id",@"Folder",@"name",@"300 MB",@"size", nil];

我也在这个网站上搜寻，但对类似的文章一无所知。
请向我解释有关在表SQLite DB的行中添加(存储)NSDictionary的更多信息。

Answer 1

您可以通过创建具有三列的表(使用create table query)来做到这一点。然后将字典中的这些对象插入到这些列中(使用插入查询)。

编辑:对于插入数据使用查询:

            NSString *query = [NSString stringWithFormat:@"insert into tablename (column1, column2,column3) values('%@','%@','%@')",[dic objectForKey:@"id"],[dic objectForKey:@"name"],[dic objectForKey:@"size"]];
            NSLog(@"query : %@",query);
            [self executeQuery:query];

在.h类中，创建一个sqlite实例:

sqlite3 *database; and import:  #import<sqlite3.h>

在.m类中添加以下方法:

-(NSString *) dataFilePath
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSLog(@"PATH %@",[documentsDirectory stringByAppendingPathComponent:DatabaseName]);
    return [documentsDirectory stringByAppendingPathComponent:DatabaseName];
}

/*==================================================================
              METHOD FOR INSERTING DATA IN DATABASE
 ==================================================================*/
-(void)executeQuery:(NSString *)query
{
    //NSLog(@"QUERY : %@",query);

    sqlite3_stmt *statement;
    if(sqlite3_open([[self dataFilePath] UTF8String], &database) == SQLITE_OK)
    {
        if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, NULL) == SQLITE_OK)
        {
            if (sqlite3_step(statement) != SQLITE_DONE)
            {
                sqlite3_finalize(statement);
            }
        }
        else
        {
            NSLog(@"query Statement Not Compiled");
        }

        sqlite3_finalize(statement);
        sqlite3_close(database);
    }
    else
    {
        NSLog(@"Data not Opened");
    }
}

对于读取数据:

/*==================================================================
 METHOD FOR Fetching Data FROM DATABASE
 ==================================================================*/
 NSString *query = [NSString stringWithFormat:@"select * from table_name"];
NSMutableArray *tableData = [self fetchingDataFromTable:query];

//这里的表数据数组包含所有记录

-(NSMutableArray *)fetchingDataFromTable:(NSString *)query;
{
    NSLog(@"QUERY : %@",query);

    NSString *idToReturn=@"";
    NSMutableArray *returnArray = [NSMutableArray new];
    if(sqlite3_open([[self dataFilePath] UTF8String], &database) == SQLITE_OK)
    {
        sqlite3_stmt *statement;
        if (sqlite3_prepare_v2(database, [query UTF8String], -1, &statement, nil)==SQLITE_OK)
        {
            while(sqlite3_step(statement)==SQLITE_ROW)
            {
                NSMutableDictionary *temp= [NSMutableDictionary new];
                const char *s;


                s=(char *)sqlite3_column_text(statement, 0);
                if(s==NULL)
                {
                    idToReturn=@"";
                }
                else
                {
                    idToReturn =[NSString stringWithUTF8String:s];
                }
                [temp setObject:idToReturn forKey:@"id"];

                s=(char *)sqlite3_column_text(statement, 1);
                if(s==NULL)
                {
                    idToReturn=@"";
                }
                else
                {
                    idToReturn =[NSString stringWithUTF8String:s];
                }
                [temp setObject:idToReturn forKey:@"name"];

                s=(char *)sqlite3_column_text(statement, 2);
                if(s==NULL)
                {
                    idToReturn=@"";
                }
                else
                {
                    idToReturn =[NSString stringWithUTF8String:s];
                }
                [temp setObject:idToReturn forKey:@"size"];

                if (temp != nil)
                {
                    [returnArray addObject:temp];

                    temp = nil;
                }

            }
            sqlite3_finalize(statement);
            sqlite3_close(database);
        }
    }
    return returnArray;

}

希望对您有帮助。