How to query by date format yyyy-mm-dd?

Short text... so you can't use numeric comparison operator.

What you can do is use SQL side query to convert column then use numeric operator on the expression.

Something like below, assuming it's MS Access.

Select Column1, DateValue(ShortTextDateColumn) as [NewName] FROM Table
Where DateValue(ShortTextDateColumn) <= SomeDateValue

EDIT: 'can' should be can't in first sentence. Fixed.