Re: QueryBrowser 1.1.1 - edit fields

Raphael Matthias Krug wrote:

>Hi Adam,
>
>one stupid question. What difference does it make in your example, if 
>this one columne has a primary key?
>  
>
You cannot have a primary key in this table. You would need another
column, for example,

Key  | Data1  |
-----|--------+
  1      1
  2      1
  3      2
  4      1

Then if Key is the primary key, then row two is updated UPDATE table SET
Data1=X WHERE Key=2

There is no ambiguity anymore. Key can be an NOT NULL AUTO_INCREMENT
column (for example) so you don't even need to specify it during INSERTs.

>I my opinion it would make sense to update all fields, which contain 1. 
>But I am only a user, not a programmer :-)
>  
>
Well, no. What about if you want the table to look like 1, 5, 2, 1 ? The
only way possible is to use LIMIT in UPDATE or DELETE, but with no
primary key, you don't know which "row" you are updating or deleting.


>>Without a primary key it is not possible to determine that a given row
>>is unique. For example,
>>
>>Data1   |
>>--------+
>>1
>>1
>>2
>>1
>>    
>>

- Adam


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