does anyone know how I can add one dataset (=table row/query row) to an already existing table (that already contains a few entries).
I work on a database for a person with only a few database skills, so my idea was that all her entries (existing of many forms) will be pasted in one table. Then she sees all her entries belonging to one dataset in a query. After this step this one dataset shall be pasted in a “master table” where all the data (ever inserted into the database) is inside and that is later used for some analysis.
We really need that pasting process (from table row/query row to master table) to prevent unwanted mistakes. The other solutions I found in the internet were not a very helpful problem solution.
Thank you so much for your help.
Related
I'm trying to create a small MS Access database to ease up my everyday job. The problem is I'm a noob when it comes to databases. I'm trying to prevent the user from accidentaly updating the wrong record.
I have a table of records, some of which are not 100% complete.
I created a query that lists only these incomplete records.
On a form, the mentioned query is fed into a listbox.
I want the user to be able to pick an incomplete record from this listbox and fill in some of the remaining parts of the record in a bunch of text boxes. What I don't like is that the record gets updated as you fill in the form fields (they're bound to the table) WITHOUT any request for confirmation. If the user picks a wrong record at the start, the records are gonna get messy with every text box filled. Or that's what seems to be happening.
Here's my idea of the user form:
Is there a correct way to do this? I could force it all with VBA but I'd rather avoid that and use a more native (correct) solution.
Thank you for any answers.
Table constraints are an important part of database design. Any grouping of elements that together are required should be in their own table. This way the required fields must be entered for every record in that table.
For each data entry step you will have one or more tables representing the required data of that step.
If you are following database normalization best practices this should be simple to achieve because your data will already be broken down in to small elements that can have required fields to complete each record.
If you have a record that contains fields that are filled out at different steps then that is a design smell that indicates your table is not properly normalized.
In MS-Access, the forms will follow these rules set in the tables. You will not be able to save a record that has required fields missing.
Background
I have an app that (using typescript) has already inserted Excel data into a SQL db. All tables have PKs that are set up when populating the excel data. It's basically going from a Primary Keyless flatfile db, to a 3 table relational db, so the data is being separated among the tables.
Unfortunately, the excel spreadsheet can't be thrown away so we can just update data using only the app, because it is updated daily and the app must grab from it to update the rows for the respective tables. (This is an experiment, I know it's not the best way of doing this).
The only table that doesn't have anything that needs updating is the first table, but the second and third tables do.
One thing that stumps me is the fact that one of the columns (belonging to the third table) that is a strong identifier (isn't unique, but close) that I place in one of the tables can have missing data one day, then pop up the next.
Question
In this scenario...
If a change occurs to a row in the excel spreadsheet that was already inserted into the db, how can I detect that change without a primary key? Any workarounds people have done in past situations?
I am quite new to Pentaho Spoon and I would like to import records of an csv file to an database table. However, only unique records should be imported into the database table. That is why I need to compare EACH record with all records of the database table in order to determine if the record should be imported or not.
So far, I tried out the suggested CRUD-pattern which looks like this:
As you can see in the picture, I merge the excel input and the table input (ignore the cast-steps. I needed to cast a value because ther differed in the float format: database format was #.000000 and the csv format of float was #.0)
After the merge join, I compare the flag (which is given by the merge rows(diff) and if the compared records are new, I import them to the database table, if they are changed, I update the record and if they are deleted or identical, I simply do nothing. So far, so good.
But here is the problem: If I shuffle the records of the csv-input-file and run the transformation anew, all the records are imported anew and consequently, there are duplicated in my database table (which I wanted to avoid). To emphasize again: The right way to solve this is that each row of the csv-input-file is compared with ALL entries in the database table.
How can I realize this? Any suggestions? Thank you so much in advance!!
The Merge Rows (diff) expect the input to be sorted. Normally, you have been warned of this by a pop-up.
Put a Sort rows step on the output flow of the Excel Input, before it reaches the Merge Rows (diff).
You should do the same between the Table Input and the Merge Rows (diff). On course you may think you could do it in the sql statement of the Table Input.
However, there is a beginner trap here. You have 3 other steps Output Rows, Update and Delete which operates on the same table. And these steps may lock the table. As in Kettle all the steps are running concurrently, you do not know which steps will fire first, and the table may be locked and never be able to read even the first record. This is known in jargon as an auto-lock, and the way to solve it is to put a Sort Row step as a buffer.
You can use the 'Dimension lookup/update' control which provides the same functionality which you are trying to achieve.
Thanks,
Nilesh
I have a series of tables in an Access 2007 database. I am trying to find a way of outputting a flat-file to an excel spreadsheet that combines all of the tables so that each row of the flatfile represents a unique combination of the table rows from each table.
For example, these tables:
Would combine to make this output table:
The challenges I'm facing are:
The 'input' tables can vary in number of rows and columns, as well as quantity
The total number of rows in the final output table can get quite large (200,000+ rows)
I know Excel and VBA (in Excel) well but almost nothing about Access
Is there a way to do this in Access? Is there some native functionality in Access that I'm completely overlooking? Any pointers (even if it's "you need to read into X and Y") would be greatly appreciated!
Thanks,
Adam
As noted above:
Create a new query. Select your 3 tables as the data sources. If desired, set up joins between tables by dragging a line between a field in one table to a field in another. Without joins you will get a Cartesian Product ... every from 1st table paired with every row of 2nd table, and then each of those combination paired with every row of 3rd table. Select the fields you want included in the result set. When the query returns what you need, save it and give it a name. Then you can export that named query to Excel.
If the table is large, you could hit Excel's row / column limit though.
As it stands, I am currently looking to import data from an Excel spreadsheet into a table on a monthly basis. The header row in the spreadsheet contains the date that the original query was run.
I have one master table in access consisiting of multiple files. I would like to set up an automated process to capture the date in the header upon import, and then record it in a field for every new record that was imported.
There are two caveats here:
Spreadsheet sizes will vary depending on where data exists.
I have no control over how the data is provided. Fields that contain no data for the month will not populate to the spreadsheet.
Less frequently fields will be added that do not exist.
So far I have been identifying these new additions manually and creating a new field for them at the end of the field list. I realize that this is very inefficient and I would like to automate it, if I can.
Does anyone have any insight? Any assistance would be greatly appreciated.
OK, here's the steps you'll want to take.
Create a link from Access to your Excel spreadsheet. Access will now see this as a table.
Create a make table query using the Excel table as the source and adding the date (derived from a sub-query) as an additional field.
Then run the query. This will automatically create all the fields.
If, however, you need to create new fields in an existing table, then you'll have to use VBA, read each header in the Excel table, compare it to the schema of the existing table, and execute an alter table query to add the field.
Good luck