Fixed Error: xxxxx already exists in table, but cannot change length

[Jon W]

Affected version

2.1.0

If a setup file tries to create a new boolean column and that column already exists, it produces the following error:

xxxxx already exists in table, but cannot change length

where xxxxx is the column name.

This happens even if the column is already set to size 3 or 4, but the code is checking whether it is size 1, so it fails.

The code is on line 128-132 of XF/Db/Schema/Column:

            case 'BOOL':
            case 'BOOLEAN':
                $type = 'TINYINT';
                $length = 1;
                break;

It would probably be better to set this to 4.

 

[Snog]

Wouldn't that be the correct error since a boolean is 0 or 1 and a TINYINT with a size of 1?

Maybe I'm not understanding why a boolean would have a size greater than 1.

That and I can't imagine why you would be creating a column that already exists.

 

[Jon W]

Sure, but for some reason XenForo always seems to set TINYINT columns to a size of 4.

 

[Snog]

Sure, but for some reason XenForo always seems to set TINYINT columns to a size of 4.

Hmm... I haven't run across that. I'll keep an eye open for it.

 

[Jon W]

Hmm... I haven't run across that. I'll keep an eye open for it.

I see you always explicitly set the column size to 1 in your add-ons, so that makes sense that you wouldn't have noticed.

The default value for a tinyint is 4 though, even if you set the column type to 'bool' or 'boolean' (which then uses tinyint).

 

[Snog]

I see you always explicitly set the column size to 1 in your add-ons, so that makes sense that you wouldn't have noticed.

The default value for a tinyint is 4 though, even if you set the column type to 'bool' or 'boolean' (which then uses tinyint).

Now that is interesting. Just did a test using BOOL as the column type and it does set the size to 4. Odd, but it does happen.

 

[Snog]

I see you always explicitly set the column size to 1 in your add-ons, so that makes sense that you wouldn't have noticed.

Doing some tests, even that doesn't work any more.

$table->addColumn('column_name', 'TINYINT', 1)->setDefault(0);

Results in a size of 3.

 

[XF Bug Bot]

Thank you for reporting this issue. It has now been resolved and we are aiming to include it in a future XF release (2.1.1).

Change log:

Don't set a length when setting up boolean columns in the schema manager as we don't actually output this for integer types.

Any changes made as a result of this issue being resolved may not be rolled out here until later.

 

[Mike]

Just as a note, I couldn't actually reproduce the issue here directly (using the schema manager to create the column and then re-running the alter), though I can see why it's incorrect as we implicitly ignore lengths on integer fields because they don't actually work as lengths.

But that's also the reason I couldn't reproduce it -- the comparison code (which is just above the length check) should normally detect them as equal. I'd have to guess there was something additional that was different about the columns.

 

[Snog]

While this has nothing to do with the bug reported, and I agree that an int value is an int value, ie: a tinyint is -128 to 127 or 0 to 255, the length set in the database is a good visual reminder of what should be in that column.

IE for tinyint size...
1 - Boolean or 0 to 9
2 - 0 to 99
3 - 0 to 255
4 - Don't care

In other words, if I have the size set to 1 and there's a value of 78 in there, I know without a doubt something is wrong somewhere.

At least that's what I've always used them for.