This may be a simple one (whether it is possible or not).. I have two tables which are identical with a set of records. I need to find the best way that when one of the memo fields is modified, that the modifications get carried to the identical record on the corrisponding identical table. In many cases the field may have hundreds of words.. The only way that i know how to potentially do this is using an update query, but i am wondering if the test within is really large, will it break? Or is there another way? Thanks, A
Since you're working with Access 2010 you can use an After Update data macro to copy the changes back to the main table:
For more information see
Create a data macro
Related
I have a spreadsheet with 12290 unique reference numbers on that I need to find any payment transactions against.
For a handful id just manually do this. But for a large number like this what would be the best way?
Can I reference a notepad file in a query in anyway?
Thanks,
This is a bit long for a comment.
Although you could put the values into a giant in statement, I would recommend that you load the data into a separate table. That table can have the reference number as a primary key. You can then use a query (join or exists) to get matching values.
This also has the nice side effect that you have the reference numbers in the database, so they can be used for another purpose -- or archived so you can keep track of what your application is doing.
While using #Gordon Linoff's answer.
To upload data there are various methods.
As in the main comments ie. writing a formula in XL and copying that and run the script in Management Studio (I would keep that in a permanent table to avoid doing the same in the future, if the list is not going to be changed often.) and also I wouldn't recommend this for 12000 records, but for less than 100 records it is OK.
Using Import Export wizard of Management Studio
Create a table to hold that data and open that in Management Studio, in Edit mode and copy-paste data to the table.
I have a table with 5 fields that are all the same. They each can hold a reference to a row from another table with relationships. I want to update all of these fields at the same time on a row, but with a randomly selected row from the table for each field (with no duplicates). I am not sure how in access SQL you can update a lookup/relationship field like this. Any advice is greatly appreciated.
Simple answer is that you can't, not as it appears you would like to anyway. The closest thing possible would be to create an Insert query with parameters, and then feed in your 5 values using VBA. Since you will have to use VBA anyway, you may as well go the whole hog and conduct the entire process with Recordsets.
But that's not the fiddly part, (relatively speaking) selecting your source values is. What you will need to do is open a Recordset on your source table, and hook it up to your random-no-duplicates logic in order to select your 5 record references, then you open up a Recordset on your destination table, and drop them in the appropriate fields.
This tutorial will get you started on Recordsets: http://www.utteraccess.com/wiki/index.php/Recordsets_for_Beginners
Here is the problem: I am currently working with a Microsoft Access database that the previous employee created by just adding all the data into one table (yes, all the data into one table). There are about 186 columns in that one table.
I am now responsible for dividing each category of data into its own table. Everything is going fine although progress is too slow. Is there perhaps an SQL command that will somehow divide each category of data into its proper table? As of now I am manually looking at the main table and carefully transferring groups of data into each respective table along with its proper IDs making sure data is not corrupted. Here is the layout I have so far:
Note: I am probably one of the very few at my campus with database experience.
I would approach this as a classic normalisation process. Your single hugely wide table should contain all of the entities within your domain so as long as you understand the domain you should be able to normalise the structure until you're happy with it.
To create your foreign key lookups run distinct queries against the columns your going to remove and then add the key values back in.
It sounds like you know what you're doing already ? Are you just looking for reassurance that you're on the right track ? (Which it looks like you are).
Good luck though, and enjoy it - it sounds like a good little piece of work.
I have 2 different databases. Upon changing something in the big one (i don't have access to), i get some rows imported in my databases in a similar HUGE table. I have a job checking for records in this table, and if any, execute a stored procedure, process and delete from table.
Performance. (Huge amount of data) I would like to know what is the fastest way to know if something has changed using let's say 2 imported rows with 100 columns each. Don't have FK-s, don't need. Chances are, that even though I have records in my table, nothing has actually changed.
Also. Let's say there is actually changed something. Is it possible for example to check only for changes inside datetime columns?
Thanks
You can always use update triggers - these will give you access to two logical tables, inserted and updated. You can compare the values of these and base your action on the results.
I've got about 25 tables that I'd like to update with random data that's picked from a subset of data. I'd like the data to be picked at random but meaningful -- like changing all the first names in a database to new first names at random. So I don't want random garbage in the fields, I'd like to pull from a temp table that's populated ahead of time.
The only way I can think of to do this is with a loop and some dynamic sql.
insert pick-from names into temp table
with id field
foreach table name in a list of
tables:
build a dynamic sql that updates all
first name fields to be a name
picked at random from the temp table based on rand() * max(id) from temp table
But anytime I think "loop" in SQL I figure I'm doing something wrong.
The database in question has a lot of denormalized tables in it, so that's why I think I'd need a loop (the first name fields are scattered across the database).
Is there a better way?
Red Gate have a product called SQL Data Generator that can generate fake names and other fake data for testing purposes. It's not free, but they have a trial so you can test it out, and it might be faster than trying to do it yourself.
(Disclaimer: I have never used this product, but I've been very happy with some of their other products.)
I wrote a stored procedure to do something like this a while back. It is not as good as the Red Gate product and only does names, but if you need something quick and dirty, you can download it from
http://www.joebooth-consulting.com/products/
The script name is GenRandNames.sql
Hope this helps
Breaking the 4th wall a bit by answering my own question.
I did try this as a sql script. What I learned is that SQL pretty much sucks at random. The script was slow and weird -- functions that referenced views that were only created for the script and couldn't be made in tempdb.
So I made a console app.
Generate your random data, easy
to do with the Random class (just
remember to only use one instance of
Random).
Figure out what columns and table
names that you'd like to update via
a script that looks at
information_schema.
Get the IDs
for all the tables that you're going
to update, if possible (and wow will
it be slow if you have a large table
that doesn't have any good PKs).
Update each table 100 rows at a time. Why 100? No idea. Could be 1000. I just picked a number. Dictionary is handy here: pick a random ID from the dict using the Random class.
Wash, rinse, repeat. I updated about 2.2 million rows in an hour this way. Maybe it could be faster, but it was doing many small updates so it didn't get in anyone's way.