editing and amendment of DB or its tables.

[bazz]

Hi again,

As you might know I am just getting started now on my MySQL Db proper.

To assist with my comparitively low confidence levels, I ask this question....

If I set up the DB or any of its tables ot their fields wrongly, is it a straightforwadr matter of changing various values via phpMyAdmin or by coding directly, without losing any data or other tables settings?

I hope so, so that I can make a bit more progress. Y'see, i think I have my hand written tables normalised but I haven't yet spent much time learning how to setup each table and the fields in each.

bazz

[zro@rtv]

you should be able to edit tables with phpMyAdmin very easily, and not necessarily loose any data.

I would suggest setting up a 'test' DB, and experimenting with phpMyAdmin more.

[bazz]

Thanks.

Now, why didn't I think of that :rolleyes:

bazz

[guelphdad]

you do have to be a bit careful. if for instance you have a char(50) field and have some rows with 50 characters but changed your table to varchar(40) then those fields would be truncated.

similar with int type fields, if you have very large values but change them to a smaller type those values could also get truncated.

[bazz]

Thanks very much guelphdad. I have used values which I think are high enough and shall try to remember never, to shorten them. Indeed, they may have to be lengthened.

As for the text field is it better to use tinytext or to use text(20)?

bazz

[guelphdad]

well text(20) doesn't work like you think it does probably. the (20) I believe specifies the size of the index, here the first 20 characters are indexed. is that your understanding or were you thinking it limited your entire field to 20 characters?

also have you seen this chart (http://codingforums.com/showpost.php?p=540233&postcount=6) for a quick reference on the size of values or amount of text that can go into a field?

[bazz]

hey; now that is useful. I hadn't seen it before and I think I will be seeing a lot more of it in the next few days/weeks.
I had overlooked the stickies :(
Thanks for that

bazz