SQLite 查询无法正常工作

Question

I have made every attempt that I know of to make this work, but at this point I think I am just running in circles.

I am taking user input and using that to query a database. The caveat is that there are dates within the database that need to have days added to them, and to make sure that the user is seeing all the UPDATED information between the dates they chose, I changed the user's start date so that it includes two months beforehand.

At this point, the information is passed into a dataframe where it is then filtered to contain only relevant information as well as adjusting the dates that need to be adjusted. After that, it's passed through a mask on the dataframe to make sure that the user is seeing the updated information only, and not dates that are outside of their chosen range that originally weren't.

There were a few points throughout this process that my code was running properly, but I kept realizing there were changes that needed to be made. As to be expected, those changes caused my code to break and I've not been able to figure out how to fix it.

One issue is that the SQL queries are not returning the correct information. It seems that the chosen start date will allow any entries past that date, but the chosen end date will only include database entries if the end date is very near to the highest date in the database. The problem with that is that the user may not always know what the highest value in the database is, therefore they need to be able to choose an arbitrary value to query by.

There is an also an issue where it seems the query only wants to work some of the time. On two separate instances I ran the same exact queries and it only worked one time and not the other.

Here is my code:

 self.StartDate = (self.StartMonth.get() + " " + self.StartDay.get() + "," + " " + self.StartYear.get())
    self.StartDate = datetime.strptime(self.StartDate, '%b %d, %Y').date()
    self.StartDate = self.StartDate - timedelta(days = 60)
    self.StartDate = self.StartDate.strftime('%b %d, %Y')

    self.EndDate = (self.EndMonth.get() + " " + self.EndDay.get() + "," + " " + self.EndYear.get())
    self.EndDate = datetime.strptime(self.EndDate, '%b %d, %Y').date()
    self.EndDate = self.EndDate.strftime('%b %d, %Y')

    JobType = self.JobType.get()

    if JobType == 'All':
        self.cursor.execute('''
                            SELECT
                                *
                            FROM
                                MainTable
                            WHERE
                                ETADate >= ? and
                                ETADate <= ?
                            ''',
                            (self.StartDate, self.EndDate,)
                            )
        self.data = self.cursor.fetchall()
    else:
        self.cursor.execute('''
                            SELECT
                                *
                            FROM
                                MainTable
                            WHERE
                                ETADate BETWEEN
                                    ? AND ?
                                AND EndUse = ?
                            ''',
                            (self.StartDate, self.EndDate, JobType,)
                            )
        self.data = self.cursor.fetchall()

    self.Data_Cleanup()
    
def Data_Cleanup(self):

    self.df = pd.DataFrame  (
                            self.data, 
                            columns =   [
                                        'id',
                                        'JobNumber',
                                        'ETADate',
                                        'Balance',
                                        'EndUse',
                                        'PayType'
                                        ]
                            )

    remove = ['id', 'JobNumber']
    self.df = self.df.drop(columns = remove)
    self.df['ETADate'] = pd.to_datetime(self.df['ETADate'])
    self.df.loc[self.df['PayType'] == '14 Days', 'ETADate'] = self.df['ETADate'] + timedelta(days = 14)
    self.df.loc[self.df['PayType'] == '30 Days', 'ETADate'] = self.df['ETADate'] + timedelta(days = 30)

    self.df['ETADate'] = self.df['ETADate'].astype('category')
    self.df['EndUse'] = self.df['EndUse'].astype('category')
    self.df['PayType'] = self.df['PayType'].astype('category')


    mask = (self.df['ETADate'] >= self.StartDate) & (self.df['ETADate'] <= self.EndDate)
    print(self.df.loc[mask])

Ideally, the data would be updated before it is added to the database, but unfortunately the source of this data isn't capable of updating it correctly.

I appreciate any help.

Answer 1

You are storing dates as a string, formatted like Jan 02, 2021 . That means you'll compare the month first, alphabetically, then the day numerically, then the year. Or, to take a few random dates, the sort order looks like this:

Dec 23, 2021
Jan 01, 2021
Nov 07, 2026
Nov 16, 2025

If you want a query that makes sense, you'll either need quite a bit of SQL logic to parse these dates on the SQLite side, or preferably, just store the dates using a format that sorts correctly as a string. If you use .strftime("%Y-%m-%d") those same dates will sort in order:

2021-01-01
2021-12-23
2025-11-16
2026-11-07

This will require changing the format of the columns in your database, of course.