If I receive post data with Flask, put that data into a WTForms form and it successfully validates, is it safe from SQL injection attacks?

Question

I am using Flask, WTForms, and the OurSQL MySQL library for my app. I receive post data from the request.form variable. I put that into a WTForms form object. I call validate() on that form, and then insert the form data into a MySQL database using OurSQL.

Without doing any additional processing, am I safe from SQL injection? Does the WTForms validate method do escaping? If not, what should I do to escape the data? An example of what I am doing looks like this:

form = MyWTFFormsForm(request.form)
if form.validate():
    cursor.execute("INSERT INTO mytable VALUES (?, ?, ?, ?, ?);",
            (form.field1.data, form.field2.data, form.field3.data,
             form.field4.data,
             form.field5.data))

Answer 1

As far as I know, neither WTForms nor Flask escape the data for SQL, but using placeholders like you're doing there eliminates the need for escaping.