The most significant difference between this function and that one is that when we add a new record we use db.session.add(record) and here, we do not.“flash cache compression expands capacity to 88TB ( raw)” This is also very similar to the way we added a new record. However, we do not write the record back to the database unless the form data validates. In lines 187–191, we add the form data to sock - which contains the record retrieved from the database in line 185. We are validating the data in exactly the same way (the else clause following line 202 is practically the same). Note that we are in fact using the same form that we used there. This is a bit more complicated than the deletion function, but recall the way we added a new record, at the start of this chapter. commit () # create a message to send to the template message = f 'The data for sock has been updated.' return render_template ( 'result.html', message = message ) else : form # get today's date from function, above all the routes updated = stringdate () # the data to be inserted into Sock model - the table, socks record = Sock ( name, style, color, quantity, price, updated ) # Flask-SQLAlchemy magic adds record to database db.

route ( '/add_record', methods = ) def add_record (): form1 = AddRecord () if form1. NumberRange() allows us to provide a minimum and maximum number for an integer or a float. Length() allows us to provide a minimum and maximum length for the string. The message= value inside the parentheses will appear if the pattern is not matched. Learn about regular expressions in Python. Regexp() is used to provide a regular expression, which is a pattern the entered string needs to match. InputRequired() means the field cannot be left empty. self represents the new instance of the class, and everywhere you see it, it needs to stay.Ĭlass AddRecord ( FlaskForm ): # id used only by update/edit id_field = HiddenField () name = StringField ( 'Sock name', +$', message = 'Invalid sock name' ), Length ( min = 3, max = 25, message = 'Invalid sock name length' ) ]) style = SelectField ( 'Choose the sock style', , choices = ) color = StringField ( 'Color', +$', message = 'Invalid color' ), Length ( min = 3, max = 25, message = 'Invalid color length' ) ]) quantity = IntegerField ( 'Quantity in stock', ) price = FloatField ( 'Retail price per pair', ) # updated - date - handled in the route function updated = HiddenField () submit = SubmitField ( 'Add/Update Record' ) Note that the order matters! You’ll see this in the first new route. Here, it specifies that when we pass values into a new record in this table, the order of the values will be name, style, color, quantity, price, updated. It is called when an object is created from the class, to initialize the properties of the class. _init_() is a reserved method in Python classes. Lines 45–51 were not needed there, but now we need them, or we’ll get an error when we try to write a new record into this table in the database. Lines 35–43 were explained in the chapter about reading from a database. String ) def _init_ ( self, name, style, color, quantity, price, updated ): self. Integer, primary_key = True ) name = db. # each table in the database needs a class to be created for it # db.Model is required - don't change it # identify all columns by name and data type class Sock ( db. Line 17: required by WTForms covered in the forms chapter.Įverything else above was covered in previous chapters. Line 12: import to enable Python to insert a date automatically into your database. Line 11: new form validators to prevent unwanted values going into your database. Line 10: new form fields you have not seen before, because the form here has a lot more going on than the simple form in the introductory chapter. Line 5: new imports from Flask - request and flash. config = True # this variable, db, will be used for all SQLAlchemy commands db = SQLAlchemy ( app ) config = 'MLXH243GssUWwKdTWS7FDhdwYF56wPj8' # Flask-Bootstrap requires this line Bootstrap ( app ) # the name of the database add path if necessary db_name = 'sockmarket.db' app.

''' write to a SQLite database with forms, templates add new record, delete a record, edit/update a record ''' from flask import Flask, render_template, request, flash from flask_sqlalchemy import SQLAlchemy from flask_bootstrap import Bootstrap from flask_wtf import FlaskForm from wtforms import SubmitField, SelectField, RadioField, HiddenField, StringField, IntegerField, FloatField from wtforms.validators import InputRequired, Length, Regexp, NumberRange from datetime import date app = Flask ( _name_ ) # Flask-WTF requires an enryption key - the string can be anything app.

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