I've prohibited duplicate records in access database so no one will insert same data again and again. it works fine, but the error message is not helpful to the users, i want to show that error in a more human way possible.
Microsoft JET Database Engine (0x80004005)
The changes you requested to the table were not successful because
they would create duplicate values in the index, primary key, or
relationship. Change the data in the field or fields that contain
duplicate data, remove the index, or redefine the index to permit
duplicate entries and try again.
Instead of this lengthy message i just want to show "Sorry - Record already exist."
Is this possible?
Two ways to do this:
Catch the error. I think classic ASP requires on error resume next and then you need to check the err message. You might even have to match the string since I think the error code will be the same for different errors.
Do a select from the database before the insert to check if the value already exists
Either way you can then display your own message. Might be even more user-friendly to customize the message further ("Sorry - species 'Gruffalo' already exists").
Related
I'm using an OLE DB Destination to insert data to a database. In the event of an error, I'm converting the data set to XML and writing it to a table; However, when the insert fails (in this scenario it was due to a foreign key violation) I'm not getting any useful information within the ErrorCode/Description passed out of the Insert action.
If I set my insert to FAIL upon error instead of redirect row, I can get at a useful error within the execution results:
This is the sort of information I was hoping would be output in the error description from the insert component.
I have considered using EventHandlers here, but I want to keep the failures row-by-row rather than failing the entire thing.
I have in Microsoft Access a linked table to an ASE Server.
On the server side, the table has no primary key or identity columns.
And has a trigger on insert that validates new entries, so that when the entry is not validated it deletes the entry from the table and writes to "table"_ERR to let the users know what error was produced.
When linking it to Access a composite key is created using 10 columns.
I have this same setup in 10 different tables (all with triggers all linked to Access)
In this particular table when trying to insert/append records to the table through Access i always get the error message:
Single-row update/delete affected more than one row of a linked table. Unique index contains duplicate values.
This error occurs when both table and table_ERR are empty and i'm only trying to insert 1 record.
If I disable the trigger i have no problem inserting records through Access
I have similar triggers in other tables that are working correctly.
What can be causing this issue and does anyone know how to solve this?
I have read that MS Access can mess up the ##identity, even so none of the solutions presented online seem to work.
links : https://groups.google.com/forum/#!msg/microsoft.public.sqlserver.programming/McHdRpPKMhs/SlyObU8w7JMJ
Stop Access from using wrong identity when appending to linked table on SQL server
Thanks in advance.
EDIT: if i try to insert the records directly from a management software (like Aqua Data Studio) there are no erros
Without knowing more specifics about your data itself, it is difficult to say why this might be happening.
However, it sounds like in this specific instance for this specific linked table, your 10 columns are not unique enough to prevent non-distinct rows from being selected.
Suggested fixes:
Add a primary key. Honestly, probably the best and easiest choice.
If for some reason you cannot add a new column to (or alter) your table; you may be able to re-link your table, and re-choose your 10 columns so that they are more unique.
Beyond that, I think we would need more information.
Just out of curiousity, what is the reason for having no key?
I am working on a login / registration system in node.js.
I usually query the database, to check whether the given username already exists, and if it doesn't, I create the new user.
I got the idea recently, of using the Unique Index in the MySQL database for the username. I have some questions though.
What would be the most efficient way to check for duplicates? Search the database for the given username, or use the Unique Index and catch an error from MySQL if it already exists?
I feel unsafe with MySQL spitting out errors when duplicates are made, but maybe I'm just crazy.
If I were to use the Unique Index, would it still be efficient to use it for every unique value? Such as having a Unique index for the username, email etc.?
What would be the most efficient way to check for duplicates? Search the database for the given username, or use the Unique Index and catch an error from MySQL if it already exists?
In first case you will be finding the user with username and then check whether it is found or not. So in this case your DB checks for this username and you also put one check.
Now consider second case where unique index is present. So you give mysql the data and it will try to check first and either throws the error or put the data into DB. This way you don't have to check double if the usrname is already in the DB or not. This will also save you from race conditions
If you are worrying about the mysql throwing errors then don't worry. mysql will throw an integrity error which you can catch and send appropriate response like username exists already
It's better to use Unique Indexes (with the validation occurring in the database engine), because this avoids thread races and ensures database integrity. Validating through select is unsafe and not a recommended way of doing it.
With that said, I recommend checking with a select before inserting to notify the user of the "username taken" before the tentative to insert.
Another good reason to use Unique Indexes is the performance. Depending on the size of the table, it can be way faster.
I have a query that runs everytime a user logins. Since this query regards information the user might have third-party updated recently I thought it would be a good idea to turn the user_id + information combo in the table unique. As so, everytime a user tried to save new information it would only save the one information I already didn't have. So, the first query being
INSERT INTO table VALUES ("1","cake"),("1","pie"),("1","bedsheets")
And as the user logins a second time and it being
INSERT INTO table VALUES ("1","cake"),("1","pie"),("1","bedsheets"),("1","chocolate")
It would only save ("1","chocolate") because (id,info) being an unique pair all other would not be inserted. I came upon the realization they all fail if only one fails. So my question is: is there any way to override this operation? Or do I have to query the db first to filter the information I already have? tyvm...
When you use the IGNORE Keyword, so every errors, in the execution are ignored. Example: if you have a duplicate or PRIMARY key error while executing a INSERT Statement, so it will ignored and the execution is not aborted
Use this:
I NSERT IGNORE INTO table VALUES ("1","cake"),("1","pie"),("1","bedsheets"),("1","chocolate");
We have an application that uses several SQL queries and might at times generate the odd error.
For example, it could be a :
INSERT INTO TABLE (ID, FIELD) VALUES (1, "field value");
which would result in a:
ERROR 1062 (23000): Duplicate entry '1' for key 'PRIMARY'
Because the unique primary key constraint has been violated.
Is it possible in MySQL to somehow log the error along with the query that caused it? I have tried to enable the error-log and general-log in the /etc/mysql/my.cnf but it never produced the expected result. I could enable logging of every query without their errors (pretty useless for us, we're only interested in queries that result in errors).
The errors can be caught by the applications (in our case they are, we are using Perl DBI), however when there are several statements in a stored procedure then we do not know which one as the error message does not include the text of the query, or even the name of the table involved. This makes troubleshooting quite difficult.
I am sure I am missing something obvious. For example, in Oracle this is the default behavior, query errors are logged into a text file where they can be easily identified.
This is a client thing. Isolate database accesses in an access layer and generate the log on the client. The database cannot log this.