My application has a database table that is used to record the attendance of employees. And the column attedance_status has only three possible values - "present", "absent", "on_leave", and NULL as default.
How do I add it to the database? So far I have come up with two possible ways.
Create another table attendance_status with status_id and status_value and add the above values to it. And then use the id in the application for all SQL queries.
Probably the bad way. Hardcode the values (maybe in a config file) and use it throughout the app's SQL queries.
Am I missing the right way? How should this be approached?
Either will work, but Option 1 will give you flexibility in the event that the requirements change and is the standard data model. I would, however, name my columns a little differently. I would have id, value, name. Then the references become attendance_status.id and attendance_status.value. The third column is available for use in displays or reports or whatever. value is on_leave and name is On leave.
Option 2 works provided the data input point is totally closed. If someone codes new functionality there is the risk that he or she will invent something different to mean the same thing like onLeave.
Related
i wanted to create via Excel or Oracle a database for a Storage room that is filled with all kinds of Computer parts and stuff.
I never created something like that, so i wanted to know if you could help me out giving me an advice how to create a database for a beginner
It should be possible to insert and remove parts or even update them
Hope my question is readable and understandable.
Thanks
A simple option to do that - not only the table so that you could write your own DML statements (to insert, update or delete rows) - but to create a nice application - is to use Oracle Application Express (Apex).
Depending on database version you use, it might already be installed by default. If not, ask your DBA to install it.
Alternatively, create a free account on apex.oracle.com; you'll get limited space (more than enough to do what you want to do).
In Application Builder, use the Excel file you have as a "source" which will then be used by Apex's wizard to create a table in the database, as well as application, true GUI which works and looks just fine.
If you don't have anything at all, not even an Excel file, well ... that's another problem and requires some more work to be done.
you have to know what you want (OK, a storage room)
is a single table enough to contain all information you'd want to collect?
if so, which columns (attributes) do you want to collect?
if not (for example, you'd want to "group" items), you'd need at least two tables which will be related to each other by the means of master-detail relationship, which also means that you'll have to create a foreign key constraint
which datatypes are appropriate for certain attributes? You wouldn't store item names into number datatype, right? Nor should you put dates (when item entered the storage room) as a string in varchar2 column, but into a date datatype column
etc.
Basically, YMMV.
I am trying to create a database with field descriptions for a very large excel file that I have at work. I have created 3 tables- List of sheets, list of variables(including a lookup field pointing at the List of sheets table, so that I can select the sheet to which the variable belongs), and a third table which specify some validation rule.
In this third table, I want to see two lookup fields, one specifying the sheet in which the rule applies(say, 'Select Sheet'), and another specifying the variable(say, 'Select Variable'). I can point to the two different tables, but I want to do something a bit more nuanced than that. When I give a particular sheet name to 'Select Sheet', I want the lookup field for the variable('Select Variable') to show me only those variables which exists in that sheet.
I know that there probably will be solutions using forms, but this database is going to be very detailed and there are things to do afterwards, so I do not want to get into queries and forms before all data has been recorded in tables in a neat manner.
I have a good grasp of VBA in the context of excel and I am given to understand that I can extend the applications of Access using VBA. I am ready to do that, but I want to see before that whether this is some functionality of access that I am missing. Had anyone done anything similar before, and if so, did it take VBA to do it?
My company has a really old Access 2003 .ADP front-end connected to an on-premise SQL Server. I was trying to update the front-end to MS Access 2016, which is what we're transitioning to, but when linking the tables I get all the fields in this specific table as #Deleted. I've looked around and tried to change some of the settings, but I'm really not that into SQL Server to know what I'm doing, hence asking for help.
When converting the table to local, all the info is correctly displayed, so it begs the question. Also, skipping to the last record will reveal the info on that record, or sorting/filtering reveals some of the records, but most of the table stays "#Deleted"...
Since I know you're going to ask: Yes, I need to edit the records.. Although the snapshot method would work for people trying to view the info, some of us need to edit it.
I'm hoping someone can shed some light on this,
Thanks in advance, Rafael.
There are 3 common reasons for this:
You have bit fields in SQL server, but they are null. They should be assigned a default of 0.
The table in question does NOT have a PK (primary key).
Last but not least you need (want) to add a timestamp column. Keep in mind that this is really what we call a “row version” column (so it not a date/time column, but a timestamp column). Adding this column will help access determine if a record been changed, and this is especially the case for any table/form in Access that allows editing of “real” number data types (single, double). If access does not find a timestamp column, then it reverts to a column by column comparison to determine table changes, and due to how computers handle “real” numbers (with rounding), then such comparisons often fail.
So, check for the above 3 issues. You likely should re-run the linked table manager have making any changes.
I need to use SSRS to create many different reports, and I have been trying to find the best way for me to easily create them as need, and for users to navigate them and use them for their needs.
To give you and idea of the two sets of data I am dealing with:
EDI file from our customer
Raw data output from hardware configuration
Now the EDI data is fairly consistent, so these columns are static.
The hardware data is usually a massive list of different configuration. I receive them in different flat files formats and using SSIS or other tools I get the data into Key Value Pairs. Now in a report, I use matrix to keep EDI columns static, it matches with the hardware on serial number, and Hardware data pivots.
So the report does not break, and so I don't give the user too much information, it matches up on another table where I specify what keys I want to be columns.
Here is a small example of one of my reports:
The green columns are EDI, while the orange is the hardware.
My question is, is there a better way for me to be doing this? Some reports can get complicated like needing total for certain hardware (counting hardrive space, ram total etc.) which is difficult to do dynamically.
I have tried creating in reports in this fashion, with these parameters:
This way I can create the Key columns per project and user can select what report they want to run. The default is All Data.
Is there a better way for me to create these reports? SSRS really doesn't seem to play well with dynamic pivots.
Is there a better tool that will handle these reports dynamically, or let users pick and choose what they want to see in a report?
I can't visualise your data but if I understand correctly, you could have a dropdown list showing all the unique values that are in the column you are using in the column group. Set this to be multi-value and then simply have the WHERE clause read something like
SELECT * FROM myTable WHERE myColumnGroupField IN (#myColumnChoiceParameter)
This way the user could select whichever columns they would like.
You could extend this by adding another parameter that has some preset groups of columns (I think you might have one of these already if I understand correctly) that would set the default value of the main #myColumnChoiceParameter parameter.
If you want something more flexible then you might want to look at Power BI but depending on how you intend to deploy that might not be a simple option.
You cannot dynamically create columns in SSRS but you can control the visibility of the columns.
1) Create a list in table that contains the names of all the columns that yo want to toggle and include a column titled 'All'.
2) Create a parameter that is based on this table and make sure multi-select is turned on.
3) Right click on every column that you want to toggle, select visibility and then create a condition that checks if the user either selected All or selected the column from the parameter list.
4) Train users that by selecting and deselecting from the dropdown they control whats visible.
I need to store data's change histories in database. For example some time some user modify some property of some data. The expected result is we can get the change histories for one data like
Tom changed title to 'Title one;'
James changed name to 'New name'
Steve added new_tag 'tag23'
Based on these change histories we can get all versions for some data.
Any good idea to achieve this? Not limited to traditional relation database.
These are commonly called audit tables. How I generally manage this is using triggers on the database. For every insert/update from a source table the trigger copies the data into another table called the same table name with an _AUDIT appended to it (the naming convention does not matter, it's just what I use). ORACLE provides you with something called journal tables. Using ORACLE designer (or manually) you can achieve the same thing and often developers put a _JN to the end of the journal/audit table. This, however, works the same, with triggers on the source table copying data into the audit table.
EDIT:
I should also note that you can create a new separate schema to manage just your audit tables or you can keep them in your schema with the source tables. I do both, it just depends on the situation.
I wrote an article about various options: http://blog.schauderhaft.de/2009/11/29/versioned-data/
If you are not tied to a relational database, there are things called 'append only' databases (I think), which never change data, but only append new versions. For your case this sounds kind of perfect. Unfortunately I don't know of any implementation.