Actually I have a new client & their Database has no standard naming conventions & the application is in classic asp.I have a form in which a form there are many values in the different textboxes, it it very difficult to trace the value come from which table.& also there is no erd.
I need a query from which I can get the table name with column name by giving Value.
Let's suppose I have a value having label name abc#= '6599912268'
& the new project has no ERD no standard of naming conventions... I need a fast way to know the abc# ='6599912268' is taking from which table & which column name.... like this the UI has many values which is time taken to trace manually
Is there any way to trace it?
The simple answer is no. There is no way to trace table/column it comes from by mere inspection of the value.
I suggest the following.
Find out what type of db your product is using. Where it is situatede, do you have access to it.
If you have access to the database, get to know the db structure. What each table is meant to store, the relationships etc. Speak to the db administrator or the business analayst to increase your knowledge on the product domain.
Once you have the db structure, try and compare the table to the page. Eg. The user details will most like be stored in a db table named 'Users' or 'Membership' Catch my drift?
Then have a look at the web sites source code. Look at the specific page you are at. Is the sql code embedded in the source code (asp page) or does it call a COM server or something similar? If you are "lucky" (and I say lucky for on the purpose of your problem that you are having) you fill find the sql code in the asp page.
If it calls a COM object or something similar, then you will have to dig up the source code for that, and that is most likely where you sql will reside.
There is no easy way to do this, you have to use a stored procedure to loop over all the tables in the database and search for the value, and it will probably take a while.
There's a stored procedure and examples here: Search all columns in all the tables in a database for a specific value. You'll see there are stored procedures for finding dates, strings, numbers.
Not possible, and If you search the column with the value, there is a possible chance that you get multiple columns with the same value, so how would you differentiate them and the same case is for the table.
Related
I am working on a very complex legacy ADP project in Microsoft Access that connects to a 2008 SQL Server back end. A common usage scenario is a form in datasheet view that contains an editable recordset.
The approach used through most of the database is to load the form, then build the SQL dynamically in VBA using form parameters, and apply the SQL as the RecordSource for the form. Many of the queries are quite complex, so this makes for really ugly code and a maintenance nightmare.
For the read-only recordsets, I have converted the dynamic sql to parameterized stored proceedures, which works great. Nice and clean, and easy to maintain going forward.
But for the editable recordsets, I am trying to determine the best approach:
1. Dynamic SQL - As mentioned above, I would really like to avoid this approach.
2. SQL View - The challenge here is that some of the tables are very large, so if I try to load the view and then filter it on the form, it has to pull the entire recordset from the SQL server, even though I only need a small number of rows. (Negative performance and IO impact.)
3. Use context_info - This sounds intriguing, but does not sound like a recommended approach based on discussion here: Create parameterized VIEW in SQL Server 2008 If I was developing against SQL Server 2016 I might look more into SESSION_CONTEXT.
4. Parameter Table with View - This is an idea that I am leaning towards. I would create a Parameters table in SQL, and set the parameter value (as a key/value pair) with the session ID. The view would then filter based on the current value in the parameter table. This would allow me to use a view as my RecordSource to support the edits, but the filtering would take place on the SQL Server side.
Is the parameter table indeed the best approach to take with this project, or is there another way that I could access a parameterized read-write recordset that is filtered on the server side?
I assume you talking about a non adp project now.
Even if you don’t use a view, and say bind a form directly to a linked table of 1 million rows, then access will ONLY pull down the records you requests. You simply just use the forms “where” clause of the open Form command.
So you don’t even have to use dynamic sql here.
However, you don’t want to launch a form bound to large table UNLESS you set the where clause.
You can certainly open a form without a reordsource, have the user enter some parameter values into a text box, and then go:
Dim strSQL as string
strSQL = "select * from tblCustomers where InvoiceNum = " & me.MyInvoiceTextBox
Me.RecordSoruce = strSQL
However, in most cases you better to create some type of search form. Let the user enter some values, display the results like this:
So in above, the person type in "smi". You display the results
(and in above I did use the above approach of stuffing the sql directly into the forms reocrdsource
Now on the edit buttons along the side to launch + edit one record,
I simply go:
Docmd.OpenForm "frmCustomer",,,id = & me!id
Once again, EVEN if the form is bound directly to the linked SQL server table, only the ONE record will be pulled from SQL server. So no messing with sql, no messing with parameters etc. is required.
So a regular non ADP access application with linked tables DOES NOT pull the whole table.
You can also after opening a form set the forms filter – and again access will ONLY pull the reocrds in question from the linked sql table. It is a “common” myth that access pulls all records – it does not if you provide a filter, and I recommend you open a form to one record, let the user work then close the form and return back to some search screen in which you ready to do battle with the next customer etc.
so provide a search form - don't recommend having the form to edit data be all cluttered up with the ability to search records. Let the user edit, and then close the form - this also promotes the record being saved after the user done working.
edit:
For a form that has any kind of complex joins etc., then create a view, and bind the form to that view. You use the forms "where" clause, then once again access will only pull down the one record. So for complex joins etc., yes access can often mess that query up and it runs slow. So if the form is bound to one table (that is MOST cases), then bind the form directly to the linked table. If the sql is complex, then bind the form to the linked view, and as noted in either case ALWAYS provide a "where clause" to the openform command - it will in these cases ONLY pull the one record into the form. And once again, no messy parameters, no messy sql is required on the access side - you will save MASSIVE amounts of coding if you adopt this approach, and you also get stellar performance since you limiting the reocrds pulled into that form from sql server.
I have problems with my records within my database, so I have a template with about 260,000 records and for each record they have 3 identification columns to determine what time period the record is from and location: one for year, one for month, and one for region. Then the information for identifying the specific item is TagName, and Description. The Problem I am having is when someone entered data into this database they entered different description for the same device, I know this because the tag name is the same. Can I write code that will go through the data base find the items with the same tag name and use one of the descriptions to replace the ones that are different to have a more uniform database. Also some devices do not have tag names so we would want to avoid the "" Case.
Also moving forward into the future I have added more columns to the database to allow for more information to be retrieved, is there a way that I can back fill the data to older records once I know that they have the same tag name and Description once the database is cleaned up? Thanks in advance for the information it is much appreciated.
I assume that this will have to be done with VBA of some sort to modify records by looking for the first record with that description and using a variable to assign that description to all the other items with the same tag name? I just am not sure of the correct VBA syntax to go about this. I assume a similar method would be used for the backfilling process?
Your question is rather broad and multifaceted, so I'll answer key parts in steps:
The Problem I am having is when someone entered data into this
database they entered different description for the same device, I
know this because the tag name is the same.
While you could fix up those inconsistencies easily enough with a bit of SQL code, it would be better to avoid those inconsistencies being possible in the first place:
Create a new table, let's call it 'Tags', with TagName and TagDescription fields, and with TagName set as the primary key. Ensure both fields have their Required setting to True and Allow Zero Length to False.
Populate this new table with all possible tags - you can do this with a one-off 'append query' in Access jargon (INSERT INTO statement in SQL).
Delete the tag description column from the main table.
Go into the Relationships view and add a one-to-many relation between the two tables, linking the TagName field in the main table to the TagName field in the Tags table.
As required, create a query that aggregates data from the two tables.
Also some devices do not have tag names so we would want to avoid the
"" Case.
In Access, the concept of an empty string ("") is different from the concept of a true blank or 'null'. As such, it would be a good idea to replace all empty strings (if there are any) with nulls -
UPDATE MyTable SET TagName = Null WHERE TagName = '';
You can then set the TagName field's Allow Zero Length property to False in the table designer.
Also moving forward into the future I have added more columns to the
database to allow for more information to be retrieved
Think less in terms of more columns than more tables.
I assume that this will have to be done with VBA of some sort to modify records
Either VBA, SQL, or the Access query designers (which create SQL code behind the scenes). In terms of being able to crunch through data the quickest, SQL is best, though pure VBA (and in particular, using the DAO object library) can be easier to understand and follow.
In an alternate application, the user has the ability to update their address and phone number. When these are changed, three fields will update: Old Value, New Value, and Field Changed. If the Field Changed was the address, I need to create two report pages - one with the old address and one with the new. However, if the Field Changed was the phone number, I only need to create one report page for the current address.
My initial plan was to do a Union that would have one record with the Old Value and another with the New Value. This should work when only the Address has changed. However, it won't whenever the Phone Number has changed. I assume I need to do some sort of case statement, but I'm not really sure if this is the right approach. Sorry if the data is a little confusing (I didn't design the data structure. This was provided by our professor's assistant). If you need more information, I'll try to provide it.
I'm not looking for exact SQL, but I am wondering if I'm approaching this the correct way.
What do you mean by a 1 or 2 page report? Are you outputting to a CSV, PDF, XLSX or something eles?
If you need to do this through "pure" sql I would recommend a stored procedure that is given a value stating whether it's the address or phone number that is being updated. It can then do the update and you can simply do an if statement which determines which report to run and return.
I'd recommend handling it programatically if possible. Have your code run the sql update and then call the appropriate function within your code to get the report you need. You can then easily re-use the code for that report in other ways.
I've been tasked with learning Lotus Domino Designer - not sure what I did in a previous life, but it must have been pretty bad... - and was wondering how to do a lookup on a database to get some values for selections. As this information could potentially be used in a lot of the applications, I'd prefer it only to be in the one place.
I gather I can use #DBColumn, but what happens if an entry in that lookup changes? If the unique value of the lookup is the text, then the relationship would be broken, wouldn't it? Is there any way of mimicing the idea of relational lookups?
I'm assuming I'm looking at Lotus development from the wrong angle, as this seems to be a real limitation of look ups.
I haven't found any decent learning material on the interwebs, so would appreciate any help.
Ta
You would want to store a unique ID along with the textual value in the source database (not unlike what you would do in an RDBMS). Then, only store that ID in any referencing documents, and use a computed-for-display field to lookup the display value. (There is a performance consideration here - and you could "de-normalize" the data and store the ID and text value in the referencing documents, and do some asynchronous work to keep the values in sync - eg: using a scheduled agent that runs every night or every week).
If DB1 has the key values and DB2 has the documents which will reference these values, then in the form in DB2, you would still do a #DbColumn to lookup your value list. In the lookup view in DB1, concat the text value and ID with a pipe separator (textField + "|" + ID) in the first column. That will tell Notes to store only the ID value (what follows the pipe is the "alias" and is what will be stored).
Note: I would avoid using #DocumentUniqueID as the unique ID for these values, as the Document Unique ID will change if the documents are copied and pasted, or the entire database is copied, etc. You can use the #unique formula function in a computed-when-composed field to generate something close to a unique ID (almost like an identity column in sql).
If you need relational properties, look for non-Notes solutions. It is possible to get some relational behavior using document UNIDs and update agents, but it will be harder than with a proper relational backend.
Your specific problem with referencing to a piece of text that might change can to some extent be resolved by using aliases in the choice fields. If a dialog list contains values on the form...
Foo|id1
Bar|id2
...the form will display Foo but the back-end document will store the value id1 - (and this is what you will be able to show in standard views - although xpages could solve that). Using the #DocumentUniqueID for alias can be a good idea under some circumstances.
It depends on where your using the data. The #DBLookup or #DBColumn will work in Lotus Notes fields if the fields are set to be computed for display. That way they always get the most up to date information when you open the form etc.
If you make it so the data is saved on to the document then you will have to write some update code when you need to refresh the values.
The Lotus Notes help files for designer are pretty good, have a look at that.
SM
You could use a key or alias to store the relationship to your lookup value so if the value itself changes, the connection remains because the alias is intact. For example, if your lookup values were being stored as a collection of documents, I'd have the #DBColumn retrieve Document UNID|lookup value pairs. When in display mode, you could then retrive the value using #GetDocField. If the lookup values are in a different database, then you'd have to retrieve them for display using #DBLookup and construct a view that is keyed off of the UNID or whatever key you decide to use.The only drawback to this technique is that you wouldn't be able to display the field value in views as the actual value isn't stored in the document, just a reference to it. Using XPages, though, you COULD map the relationship into a dynamic datatable just like you would in a truly relational system.
It's tricky, but using LEI, you could also use Notes to front-end a relational backend system, also giving you the dynamic relationship you desire in your lookups.
Hope this helps!
The content of the lookup can change freely. A problem only arises (as it would on any other platform in the same circumstances) if the lookup key changes. You need to use a key that won't change. Human-readable text is an advantage, but if you want to be able to change your key description from, say, "Divisions" to "Business Units" and still have lookups work, you need to use an alias of some kind, which will presumably be mapped to your text description and only used internally. #Unique is pretty good for this, and gives a shortish key, if that is important to you. #DocumentUniqueID is most reliable, but as Ed pointed out, will change (must change - it's a new document) if you copy/paste or make a non-replica copy. This is easy to get around, though. Create a Computed-when-composed field (called, say, "LookupRef") on the form you are using for your reference document with the formula "#DocumentUniqueID". That will capture the ID at the time of creation, and it will not change on copy/paste etc. Use that as your key.
problem
how to best parse/access/extract "excel file" data stored as binary data in an SQL 2005 field?
(so all the data can ultimately be stored in other fields of other tables.)
background
basically, our customer is requiring a large volume of verbose data from their users. unfortunately, our customer cannot require any kind of db export from their user. so our customer must supply some sort of UI for their user to enter the data. the UI our customer decided would be acceptable to all of their users was excel as it has a reasonably robust UI. so given all that, and our customer needs this data parsed and stored in their db automatically.
we've tried to convince our customer that the users will do this exactly once and then insist on db export! but the customer can not require db export of their users.
our customer is requiring us to parse an excel file
the customer's users are using excel as the "best" user interface to enter all the required data
the users are given blank excel templates that they must fill out
these templates have a fixed number of uniquely named tabs
these templates have a number of fixed areas (cells) that must be completed
these templates also have areas where the user will insert up to thousands of identically formatted rows
when complete, the excel file is submitted from the user by standard html file upload
our customer stores this file raw into their SQL database
given
a standard excel (".xls") file (native format, not comma or tab separated)
file is stored raw in a varbinary(max) SQL 2005 field
excel file data may not necessarily be "uniform" between rows -- i.e., we can't just assume one column is all the same data type (e.g., there may be row headers, column headers, empty cells, different "formats", ...)
requirements
code completely within SQL 2005 (stored procedures, SSIS?)
be able to access values on any worksheet (tab)
be able to access values in any cell (no formula data or dereferencing needed)
cell values must not be assumed to be "uniform" between rows -- i.e., we can't just assume one column is all the same data type (e.g., there may be row headers, column headers, empty cells, formulas, different "formats", ...)
preferences
no filesystem access (no writing temporary .xls files)
retrieve values in defined format (e.g., actual date value instead of a raw number like 39876)
My thought is that anything can be done, but there is a price to pay. In this particular case, the price seems to bee too high.
I don't have a tested solution for you, but I can share how I would give my first try on a problem like that.
My first approach would be to install excel on the SqlServer machine and code some assemblies to consume the file on your rows using excel API and then load them on Sql server as assembly procedures.
As I said, This is just a idea, I don't have details, but I'm sure others here can complement or criticize my idea.
But my real advice is to rethink the whole project. It makes no sense to read tabular data on binary files stored on a cell of a row of a table on database.
This looks like an "I wouldn't start from here" kind of a question.
The "install Excel on the server and start coding" answer looks like the only route, but it simply has to be worth exploring alternatives first: it's going to be painful, expensive and time-consuming.
I strongly feel that we're looking at a "requirement" that is the answer to the wrong problem.
What business problem is creating this need? What's driving that? Try the Five Whys as a possible way to explore the history.
It sounds like you're trying to store an entire database table inside a spreadsheet and then inside a single table's field. Wouldn't it be simpler to store the data in a database table to begin with and then export it as an XLS when required?
Without opening up an instance Excel and having Excel resolve worksheet references I'm not sure it's doable at all.
Could you write the varbinary to a Raw File Destination? And then use an Excel Source as your input to whatever step is next in your precedence constraints.
I haven't tried it, but that's what I would try.
Well, the whole setup seems a bit twisted :-) as others have already pointed out.
If you really cannot change the requirements and the whole setup: why don't you explore components such as Aspose.Cells or Syncfusion XlsIO, native .NET components, that allow you to read and interpret native Excel (XLS) files. I'm pretty such with either of the two, you should be able to read your binary Excel into a MemoryStream and then feed that into one of those Excel-reading components, and off you go.
So with a bit of .NET development and SQL CLR, I guess this should be doable - not sure if it's the best way to do it, but it should work.