I'm just learning Microsoft Access, and I'm trying to write an update query that will change the field "Date Added" to a certain date based on another field called "Plant". Example: If Plant for a record = "MP", then change [Date Added] to 6/1/2013
The problem is that the values in the Plant field range from NULL to MP18, and the years need to match. I've looked at nested IIF statements, but I don't have any experience with SQL.
Create a new table along with Plant & the corresponding dates.
Link the tables via plant and write a query to update date
Main Table
Table with Criteria
Update Query
Update tblExample as a INNER JOIN tblChange as b ON a.plant = b.plant
set a.[date added]= b.[date added]
where years = 2018
Related
I am trying to inner join a table with another table but have the join only apply if there are conditions on the right table other than the primary index field on the right table linking to a field on the left table. For example, suppose I have a Customer table and a Contact table and a query is structured the following way:
FOR EACH Customer NO-LOCK [optional conditions], FIRST Contact NO-LOCK WHERE Contact.ContactID EQ Customer.ServiceContactID [optional conditions]
If a particular Customer's ServiceContactID didn't have a corresponding record in the Contact table, that Customer would be excluded from the results set. I don't want that customer to be excluded from the results set if there are no optional conditions for the Contact section of the query.
In the part of our codebase I'm working with, I'm not able to conditionally add the join of the Contact part of the query based on the values being used for the optional conditions. The query has to stay the same except for the conditions sections which are automatically built using the values that are passed to the framework. Is there a way to do this in Progress?
If all you can do is to substitute values into a pre-existing query structure then, no, you cannot do what you describe.
So I currently have a database that keeps tracks of projects, project updates, and the update dates. I have a form that with a subform that displays the project name and the most recent update made to said project. It was brought to my attention however, that the most recent update to a project does not display correctly. Ex: shows the update date of 4/6/2017 but the actual update text is from 3/16/2017.
Doing some spot research, I then learned that Access does not store records in any particular order, and that the Last function does not actually give you the last record.
I am currently scouring google to find a solution but to no avail as of yet and have turned here in hopes of a solution or idea. Thank you for any insight you can provide in advance!
Other details:
tblProjects has fields
ID
Owner
Category_ID
Project_Name
Description
Resolution_Date
Priority
Resolution_Category_ID
tblUpdates has these fields:
ID
Project_ID
Update_Date
Update
there is no built-in Last function that I am aware of in Access or VBA, where exactly are you seeing that used?
if your sub-form is bound directly to tblUpdates, then you ought to be able to just sort the sub-form in descending order based on either ID or Update_date.
if you have query joining the two tables, and are only trying to get a single row returned from tblUpdates, then this would do that, assuming the ID column in tblUpdates is an autonumber. if not, just replace ORDER BY ID with ORDER BY Update_Date Desc
SELECT a.*,
(SELECT TOP 1 Update FROM tblUpdates b WHERE a.ID = b.PROJECT_ID ORDER BY ID DESC ) AS last_update
FROM tblProjects AS a;
I am developing an application which tracks class attendance of students in a school, in Apex.
I want to create a page with three level cascading select lists, so the teacher can first select the Semester, then the Subject and then the specific Class of that Subject, so the application returns the Students who are enrolled in that Class.
My problem is that these three tables have a many-to-many relationship between them, so I use extra tables with their keys.
Every Semester has many Subjects and a Subject can be taught in many Semesters.
Every Subject has many classes in every Semester.
The students must enroll in a subject every semester and then the teacher can assign them to a class.
The tables look something like this:
create table semester(
id number not null,
name varchar2(20) not null,
primary key(id)
);
create table subject(
id number not null,
subject_name varchar2(50) not null,
primary key(id)
);
create table student(
id number not null,
name varchar2(20),
primary key(id)
);
create table semester_subject(
id number not null,
semester_id number not null,
subject_id number not null,
primary key(id),
foreign key(semester_id) references semester(id),
foreign key(subject_id) references subject(id),
constraint unique sem_sub_uq unique(semester_id, subject_id)
);
create table class(
id number not null,
name number not null,
semester_subject_id number not null,
primary key(id),
foreign key(semester_subject_id) references semester_subject(id)
);
create table class_enrollment(
id number not null,
student_id number not null,
semester_subject_id number not null,
class_id number,
primary_key(id),
foreign key(student_id) references student(id),
foreign key(semester_subject_id) references semester_subject(id),
foreign key(class_id) references class(id)
);
The list of value for the Semester select list looks like this:
select name, id
from semester
order by 1;
The the subject select list should include the names of all the Subjects available in the semester selected above, but I can't figure the query or even if it's possible. What I have right now:
select s.name, s.id
from subject s, semester_subject ss
where ss.semester_id = :PX_SEMESTER //value from above select list
and ss.subject_id = s.id;
But you can't have two tables in a LoV and the query is probably wrong anyway...
I didn't even begin to think about what the query for the class would look like.
I appreciate any help or if you can point me in the right direction so I can figure it out myself.
Developing an Apex Input Form Using Item-Parametrized Lists of Values (LOVs)
Your initial schema design looks good. One recommendation once you've developed and tested your solution on a smaller scale, append to the ID (primary key) columns a trigger that can auto-populate its values through a sequence. You could also skip the trigger and just reference the sequence in your sql insert DML commands. It just makes things simpler. Creating tables in the APEX environment with their built-in wizards offer the opportunity to make an "auto-incrementing" key column.
There is also an additional column added to the SEMESTER table called SORT_KEY. This helps when you are storing string typed values which have logical sorting sequences that aren't exactly alphanumeric in nature.
Setting Up The Test Data Values
Here is the test data I generated to demonstrate the cascading list of values design that will work with the example.
Making Dynamic List of Value Queries
The next step is to make the first three inter-dependent List of Values definitions. As you have discovered, you can reference page parameters in your LOVs which may come from a variety of sources. In this case, the choice selection from our LOVs will be assigned to Apex Page Items.
I also thought only one table could be referenced in a single LOV query. This is incorrect. The page documentation suggests that it is the SQL query syntax that is the limiting factor. The following LOV queries reference more than one table, and they work:
-- SEMESTER LOV Query
-- name: CHOOSE_SEMESTER
select a.name d, a.id r
from semester a
where a.id in (
select b.semester_id
from semester_subject b
where b.subject_id = nvl(:P5_SUBJECT, b.subject_id))
order by a.sort_id
-- SUBJECT LOV Query
-- name: CHOOSE_SUBJECT
select a.subject_name d, a.id r
from subject a
where a.id in (
select b.subject_id
from semester_subject b
where b.semester_id = nvl(:P5_SEMESTER, b.semester_id))
order by 1
-- CLASS LOV Query
-- name: CHOOSE_CLASS
select a.name d, a.id r
from class a, semester_subject b
where a.semester_subject_id = b.id
and b.subject_id = :P5_SUBJECT
and b.semester_id = :P5_SEMESTER
order by 1
Some design notes to consider:
Don't mind the P5_ITEM notation. The page in my sample app happened to be on "page 5" and so the convention goes.
I chose to assign a name for each LOV query as a hint. Don't just embed the query in an item. Add some breathing room for yourself as a developer by making the LOV a portable object that can be referenced elsewhere if needed.
MAKE a named LOV for each query through the SHARED OBJECTS menu option of your application designer.
The extra operator involving the NVL command, as in nvl(:P5_SUBJECT, b.subject_id) for the CHOOSE_SEMESTER LOV is an expression mirrored on the CHOOSE_SUBJECT query as well. If the default value of P5_SUBJECT and P5_SEMESTER are null when entering the page, how does that assist with the handling of the cascading relationships?
The table SEMESTER_SUBJECT represents a key relationship. Why is a LOV for this table not needed?
APEX Application Form Design Using Cascading LOVs
Setting up the a page for testing the schema design and LOV queries requires the creation of three page items:
Each page item should be defined as a SELECT LIST leave all the defaults initially until you understand how the basic design works. Each select list item should be associated with their corresponding LOV, such as:
The key design twist is the Select List made for the CHOOSE_CLASS LOV, which represents a cascading dependency on more than one data source.
We will use the "Cascading Parent" option so that this item will wait until both CHOOSE_SEMESTER and CHOOSE_SUBJECT are selected. It will also refresh if either of the two are changed.
YES! The cascading parent item can consist of multiple page items/elements. They just have to be declared in a comma separated list.
From the online help info, this is a general introduction to how cascading LOVs can be used in APEX designs:
From Oracle Apex Help Docs: A cascading LOV means that the current item's list of values should be refreshed if the value of another item on this page gets changed.
Specify a comma separated list of page items to be used to trigger the refresh. You can then use those page items in the where clause of your "List of Values" SQL statement.
Demonstration of APEX Application Items with Cascading LOVs
These examples are based on the sample data given at the beginning of this solution. The path of the chosen example case is:
SEMESTER: SPRING 2014 + SUBJECT: PHYS ED + Verify Valid Course Options:
Fitness for Life
General Flexibility
Presidential Fitness Challenge
Running for Fun
Volleyball Basics
The choice from above will be assigned to page item P5_CLASS.
Selection Choices for P5_SEMESTER:
Selection Choices for P5_SUBJECT:
Selection Choices for P5_CLASS:
Closing Remarks and Discussion
Some closing thoughts that occurred to me while working with this design project:
About the Primary Keys: The notion of a generic, ID named column for a primary key was a good design choice. While APEX can handle composite business keys, it gets clumsy and difficult to work around.
One thing that made the schema design challenging to work with was that the notion of "id" transformed in the other tables that referenced it. (Such as the ID column in the SEMESTER table became SEMESTER_ID in the SEMESTER_SUBJECT table. Just keep an eye on these name changes with larger queries. At times I actually lost track exactly what ID I was working with.
A Word for Sanity: In the likely event you decide to assign ID values through a database sequence object, the default is usually to begin at one. If you have several different tables in your schema with the same column name: ID and some associating tables such as CLASS_ENROLLMENT which connects the values of one primary key ID and three additional foreign key ID's, it may get difficult to discern where the data values are coming from.
Consider offsetting your sequences or arbitrarily choosing different increments and starting values. If you're mainly pushing ID's around in your queries, if two different ID sets are separated by two or three orders of magnitude, it will be easy to know if you've pulled the right data values.
Are There MORE Cascading Relationships? If a "parent" item relationship indicates a dependency that makes a page item LOV wait or change depending on the value of another, could there be another cascading relationship to define? In the case of CHOOSE_SEMESTER and CHOOSE_SUBJECT is it possible? Is it necessary?
I was able to figure out how to make these two items hold an optional cascading dependency, but it required setting up another outside page item reference. (If it isn't optional, you get stuck in a closed loop as soon as one of the two values changes.) Fancy, but not really necessary to solve the problem at hand.
What's Left to Do? I left out some additional tasks for you to continue with, such as managing the DML into the ENROLLMENT table after selecting a valid STUDENT.
Overall, you've got a workable schema design. There is a way to represent the data relationships through an APEX application design pattern. Happy coding, it looks like a challenging project!
Im working in AX 2012.
I try to make code where i count all sales for each month and insert them into fields in a table.
These fields are called Sales1, Sales2, Sales3 etc... representing the months in a year.
is there a way i can select these fields and insert into them in a while select like this example below?
while select myTable where myTable.date >= startDate && myTable.date <= endDate
{
MyTable.("Sales" +MthOfYear(MyTable.Date)) += MyTable.SalesQty;
}
myTable.insert();
it's a stupid example, but it should show what i want to achieve... any ideas?
Regards
Kent
I think your main question is how to access a field by having its name in a string variable?
If that's the case then please see the following two links:
How to convert field name to its ID
How to access a table field by ID
In short: First of all you have to convert your field name to the corresponding field ID by using fieldName2Id. After that, you can access this field by using the syntax myTable.(fieldId).
To put it all together for your case:
myTable.(fieldName2Id(myTable.TableId, strfmt("%1%2", "Sales", mthofyr(myTable.Date)))) += myTable.SalesQty
If you have any problems or questions don't hesitate to ask via a comment.
While the fieldName2Id may save your day, it is an AX anti-pattern to have fields named Sales1, Sales2 ... Sales17. Why? Because AX supports arrays in tables (albeit only of a fixed size).
To use that, define a new extended data type SalesAmountMonth exending SalesAmount (or whatever).
Label the it "January". Then in the node "Array Elements" add an new array element for "February", "Marts" up till "December". See How to Define an Extended Data Type as an Array.
Then add the extended data type to your table.
Your field access is then quite simple:
myTable.Sales[mthofyr(myTable.Date)] += myTable.SalesQty;
I prefer using the intvNo function for date indexing like this, as it has more flexibility:
myTable.Sales[intvNo(myTable.date, startDate, IntvScale::YearMonth) + 1] += myTable.SalesQty;
By changing the IntvScale enumeration you can group by month, week, quarter or whatever it supports.
I am building a query in people soft using Peoplesoft query manager.
I am trying to pull the most recent date from the date column. I have tried using max() as an expression, however, the query doesn't pull any records.
I have checked with another co-worker and they have never been able to pull records using max().
Is there any other way or workaround to pull the most recent record?
So I figured out why no results were returned when using Max in a subquery. It was more from a lack of understanding PeopleSoft and SQL since I am relatively new to it. When I was setting the date column in the subquery as max for the aggregate to be used as criteria to compare to the date column in the main query I didn't make any criteria in the subquery. This meant that the subquery would go through all dates for all employees except for the employee that I was specifying in a prompt and returning a value that didn't match any of the dates for the employee in the main query and returning no one. This was fixed by setting a criteria in the subquery that the employee ID that had to be searched in the subquery matched the one that was typed into the prompt in the main query
Use effective date for doing such searches while using PSQuery.
Use Effective date in order to get the most recent date, max may not work properly in PeopleSoft. Query should be effective dated
PS Query has built in filters for EFFDT tables. When you add a criteria on the EFFDT field, there are some additional drop down choices on the "condition type" field like 'Eff Date <' and 'Eff Date <=', etc. Usually, when you create a query for an Effective dated table, PS Query will automatically add the subquery based on the 'Eff Date <=' condition type.