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MySQL: how to know whether an item is already in the database?


By : digimus
Date : October 16 2020, 11:12 PM
hope this fix your issue Something like SELECT 1 FROM table WHERE title = '' springs to mind, with an index on title ofcourse :)
From PHP:
code :


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When to store images in a database(mySQL) and when not? (Linking image to item in database)


By : user3858762
Date : March 29 2020, 07:55 AM
I wish this helpful for you Advantages of storing images/blobs in the database
Storing the images is automatically part of your transactions No need to cleanup the file system and sync it with the database Access to the images is controlled through the same means as access to the rest of the data Only one single backup to care about A database is usually better suited to stored million (if not billions) of records. In the filesystem you have to find a clever distribution over several directories. A single directory will not be able to handle millions of files efficiently. For some workloads storing the images in the database could actually be faster.

Php mysql database item name call from another database


By : fangqi
Date : March 29 2020, 07:55 AM
To fix the issue you can do First of all you need a column in iteme table to reference to alchimie in my following example I gave it a name alchimie_id.
Now LEFT JOIN, GROUP BY, and GROUP_CONCAT() will do the trick with a query
code :
SELECT a.nume_potiune, 
       a.nivel_potiune,
       a.nivel_caracter,
       i.obiecte_necesare
  FROM alchimie a LEFT JOIN 
(
  SELECT alchimie_id,
         GROUP_CONCAT(nume) obiecte_necesare
    FROM iteme
   GROUP BY alchimie_id
) i
    ON a.id = i.alchimie_id
|  NUME_POTIUNE | NIVEL_POTIUNE | NIVEL_CARACTER |                          OBIECTE_NECESARE |
----------------------------------------------------------------------------------------------
|         Fusar |             1 |              1 | Name of item1,Name of item2,Name of item3 |
|      Caracuda |             1 |              1 |                                    (null) |
| Tipar Chiscar |             2 |              1 |                                    (null) |
|         Salau |             2 |              2 |                                    (null) |

How to update the value of an item in a database, using mysql


By : Elbargetni
Date : March 29 2020, 07:55 AM
This might help you I am lost on where to go next, I have a database that stores, name, email, uname, password, calories. I want to update the value of the calories column based on what the username is. When a new account is created the value of calories is set to default.. , Try with this...
code :
public void insertCalories(Intents c)
{
    db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put("calories", c.getCalories);
    String selection = "where uname = ?";
    String[] selectionArgs = new String[]{c.getUname()};

    int result = db.update(
         "tbltest",
         values,
         selection,
         selectionArgs);

}

getting 2 item instead of 1 mysql database


By : Angie
Date : March 29 2020, 07:55 AM
Hope this helps I think you get 2 values because you have for example,element [0] and same element with key=name of column , so use only associatif result :
Change this :

How to add a max item limit to mysql database?


By : Travis Eden
Date : March 29 2020, 07:55 AM
Hope that helps I want to add a limit to how many items my table can have. I want the maximum amount of items to be 10. I want it to only be 10 people in my table. I dont want it to be able to add items after the 10th person. Here is my code:
code :
delimiter //   
 create trigger limit_persons before insert on person for each row
    begin
        declare count integer
        select COUNT(*) FROM person INTO count;
        if count>=10 then
            signal sqlstate '45000' set message_text = 'Limit exceeded';
        end if;
    end
//
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