DateTimePicker中的Visual Basic日期在SQL中不起作用

Question

I just need to ask about DateTimePicker since when I run the query below, I get the correct data in between the month and days but the year is wrong. DATEOFTRANSACTION has varchar as data type.

Example scenario

DateTimePicker1 = 06/10/2017

DateTimePicker2 = 10/22/2017

Database has:

06/10/2017
08/02/2017
12/15/2017
08/02/2018

After running the query my display is:

06/10/2017
08/02/2017
08/02/2018

Query String to get dates in between Picker1 and Picker2

Dim rsa As New OracleCommand(
    "SELECT * FROM DBOR WHERE DATEOFTRANSACTION BETWEEN '" 
    & Format(DateTimePicker1.Value, "MM/dd/yyyy").ToString & "' AND '" 
    & Format(DateTimePicker2.Value, "MM/dd/yyyy").ToString & "'", con)

My insert query is this

Dim rs As New OracleCommand(
    "Insert into DBOR (OR_NUMBER,FIRSTNAME,MIDDLENAME,LASTNAME,DATEOFTRANSACTION,TIMEOFTRANSACTION, PRICE, CASHIER) values ('" 
    & RECEIPTform.Label1.Text & "', '" 
    & ADDCUSTOMERform.FirstName.Text & "','" 
    & ADDCUSTOMERform.MiddleName.Text & "','" 
    & ADDCUSTOMERform.LastName.Text & "' ,'" 
    & Format(Date.Now(), "MM/dd/yyyy") & "' , '" 
    & TimeOfDay.ToString("h:mm:ss tt") & "', '" 
    & TextBox1.Text & "', '" 
    & LOGINform.username.Text & "')", con)

Answer 1

First, as commented before, you need to use parameters instead of concatenating strings values. OracleCommand.Parameters Property ie:

OracleCommand oraCommand = new OracleCommand("SELECT fullname FROM sup_sys.user_profile
                           WHERE domain_user_name = :userName", db);
oraCommand.Parameters.Add(new OracleParameter("userName", domainUser));

Second, dates stored in DB as string in this format:

YEAR(YYYY/YY)[optional separatos]Month(MM)[optional separatos]DAY(DD)

alphabetical and chronological order match, other formats, not.

You still have to deal with the problem where your dates in DB are stored as MM/DD/YYYY or DD/MM/YYYY ( I can't tell with data sample provided)

So, it is not enough that you convert your DateTimePicker in the formal MM/DD/YYYY because this string is sorted alphabetically and this does not match the chonologycal order you need.

You need to convert char field in dates or in string format YYYY/MM/DD

In order to do this, you need something like this

TO_DATE(DATEOFTRANSACTION,'MM/DD/YYYY')

It will look like this:

OracleCommand rsa = new OracleCommand("SELECT * FROM DBOR 
                WHERE TO_DATE(DATEOFTRANSACTION,'MM/DD/YYYY') 
                BETWEEN iniDate = :iniDate AND endDate= :endDate", con);
rsa.Parameters.Add(new OracleParameter("iniDate", DateTimePicker1.Value));
rsa.Parameters.Add(new OracleParameter("endDate", DateTimePicker2.Value));

EDIT: I just realized it is used MM/DD/YYYY format, but I'll leave the previous comment for others to see probable problems.