Chapter 8, Problem 6CAT

Explanation of Solution

a.

Deleting query in the table “GUIDE”:

Public Function GuideDelete(I_GUIDE_NUM)

    Dim strSQL As String

    strSQL = "DELETE FROM GUIDE WHERE GUIDE_NUM = '"

    strSQL = strSQL & I_GUIDE_NUM

    strSQL = strSQL & "'"

    DoCmd.RunSQL strSQL

 End Function

 Explanation:

• Create a function named as “GuideDelete” and pass an argument “I_GUIDE_NUM”.
• Set the “strSQL” string variable to “DELETE FROM GUIDE WHERE GUIDE_NUM = '” and makes everything necessary in the command up to and including the single quotation mark preceding the order number.
• The next command will concatenated previous value with the value in “I_GUIDE_NUM”.
• The final command is used to set “strSQL” to the output of the value already created, concatenated with a single quotation mark...

Explanation of Solution

b.

Updating query:

Public Function GuideUpdate(I_GUIDE_NUM, I_LAST_NAME)

    Dim strSQL As String

    strSQL = "UPDATE GUIDE SET LAST_NAME = '"

    strSQL = strSQL + I_LAST_NAME

    strSQL = strSQL + "' WHERE GUIDE_NUM = '"

    strSQL = strSQL & I_GUIDE_NUM

    strSQL = strSQL & "'"

    DoCmd.RunSQL strSQL

End Function

 Explanation:

• Create a function named as “GuideUpdate” and pass the arguments “I_GUIDE_NUM” and “I_ LAST_NAME”.
• Set the “strSQL” string variable to “UPDATE GUIDE SET LAST_NAME = '” and makes everything necessary in the command up to and including the single quotation mark preceding the order number.
• Here, the user pass two arguments, so there are two portions of the construction of the SQL command that involve variables...

Explanation of Solution

c.

Retrieving the list in the table “RESERVATION”:

Public Function FindReservations(I_CUSTOMER_NUM)

    Dim rs As New ADODB.Recordset

    Dim cnn As ADODB.Connection

    Dim strSQL As String

    Set cnn = CurrentProject.Connection

    strSQL = "SELECT RESERVATION_ID, TRIP_ID, NUM_PERSONS, TRIP_PRICE FROM RESERVATION WHERE CUSTOMER_NUM = '"

    strSQL = strSQL & I_CUSTOMER_NUM

    strSQL = strSQL & "'"

    rs.Open strSQL, cnn, adOpenStatic, , adCmdText

    Do Until rs.EOF

        Debug.Print (rs!RESERVATION_ID)

        Debug.Print (rs!TRIP_ID)

        Debug.Print (rs!NUM_PERSONS)

        Debug.Print (rs!TRIP_PRICE)

        rs.MoveNext

    Loop

End Function

 Explanation:

• Create a function named as “Find_Reservations” and pass an argument “I_CUSTOMER_NUM”.
• The “rs” and “cnn” is used to processing the “Recordset” and “ADODB.Connection”.
• Set the “strSQL” string variable to “SELECT RESERVATION_ID, TRIP_ID, NUM_PERSONS, TRIP_PRICE FROM RESERVATION WHERE CUSTOMER_NUM = '” and makes everything necessary in the command up to and including the single quotation mark preceding the order number...