9 replies to this topic

[Robbie.Knox]

Ok I'm a bit of a beginner when it comes to MySQL. I'm trying to create a table with fields, so obviously I have to declare the lengths of the Varchar fields. If i set it to 20, and I tried inputting a name that's 24 characters long, what would happen?

Thanks

[Mr. Matt]

it would just cut the end of it off i beleive.

[Robbie.Knox]

So if I was for example doing a script, where people type their name into a text box and press submit, and it enters into a database, how would I stop it cutting any off? Would I use Text as the field type? Or limit the characters entered into the text field.

Cheers

[Av-]

Just make sure you make your field large enough. I believe the max length for a varchar field is 255 characters. There's no reason for anybody to have a username longer than 255 chars, so you should be good

[Robbie.Knox]

Ok but if I stuck it to 255, wouldn't that waste space in the database?

Sorry I'm just new to this.

[rc69]

If we were dealing with C, i could give you a definate answer to that. But since we are not i can only say that, theoretically, yes, it will waste space.

Thats why you have to choose. What is the max length a user name should have. 50 characters maybe? If so, then make a note of that next to the input field (possibly even add the maxlength attribute so they can't enter a name longer than the field).

[Robbie.Knox]

Alright thanks. I was just wandering what scripts such as IPB and vBuletin do to handle this.

[WkD]

It shouldnt waste any space should it ?? your only setting the max number of characters you can enter so you should only take up the space needed to store the input should you not.

if im wrong sorry

[Robbie.Knox]

I thought it wouldn't but apparently if you set it to hold 20 characters, and the data entered is only 10, the other 10 characters will still be stored as blanks, which could affect big websites.

Thanks for all the replies by the way.

[joe]

Robbie.Knox, on May 26 2007, 03:47 AM, said:

I thought it wouldn't but apparently if you set it to hold 20 characters, and the data entered is only 10, the other 10 characters will still be stored as blanks, which could affect big websites.

Thanks for all the replies by the way.

but it depends on the variable type in table which you want to use. For example, for username, i prefer to choose variable type : varchar than char on MySQL.
but, i think it depends to the programmer...

joe