MS SQL Add Column Error

When I add a column, e.g. PersistedGeneratedYieldCurves column to the Calculation table, and I press Save, HeidiSQL executes:

ALTER TABLE "dbo"."Calculation"
ALTER COLUMN  "PersistedGeneratedYieldCurves" BIT NOT NULL;
EXECUTE sp_addextendedproperty 'MS_Description', '', 'user', 'root', 'table', 'Calculation', 'column', 'PersistedGeneratedYieldCurves';

The first statement actually succeeds, but the second statement fails:

/* SQL Error (15135): Object is invalid. Extended properties are not permitted on 'root.Calculation.PersistedGeneratedYieldCurves', or the object does not exist. */

I'm not sure whether that second statement is necessary. I never use extended properties, but if it's really necessary, shouldn't it be something like this:

EXECUTE sp_addextendedproperty 'MS_Description', '', 'Schema', 'dbo', 'table', 'Calculation', 'column', 'PersistedGeneratedYieldCurves';

Hi ansgar, have you had a chance to look at this?

i have similiar error:when i try to add a comment in ACCION.ACCESO
where accion is table name and acceso is field name

ALTER TABLE "dbo"."ACCESOS"
ALTER COLUMN "ACCESO" VARCHAR(15) NOT NULL;
EXECUTE sp_addextendedproperty 'MS_Description', 'asasas', 'user', 'miquel', 'table', 'ACCESOS', 'column', 'ACCESO';
/* Error de SQL (15135): Objeto no válido. 'miquel.ACCESOS.ACCESO' no admite propiedades extendidas o el objeto no existe. */

i need to add comments in all DB and i don't know how to do it....

Ansgar, I beg you, please have a look at this. I run into this problem at least twice a day.

r4998 now uses that "'schema', 'dbo'" syntax instead of "'user', 'root'".

Hope that doesn't break something else, but I couldn't find the place where I found that sp_addextendedproperty query before. This is the only way I found how to change a column's comment in MSSQL. Is there a more "normal" way than that?

r4998 work for me. I'll look into finding a more 'normal' way. Thanks very much!

Isn't it simpler to execute sp_addextendedproperty statement only when the comment field has been populated. For most cases when I add a column, I leave the comment field blank, so there is no need to execute the statement.

For editing an existing field, the statement should be executed only if the comment field has changed.