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Generated update obviously fails on readonly fieldWith VS 2005/NET 2.0, I add a datasource in my project, and the Dataset Designer creates automaticaly the SELECT, INSERT, UPDATE and DELETE functions/clauses. BUT the UPDATE include all the fields of the table, included some read-only or calculated fields. And thus, obviously, any attempt to update FAILS!!! 1 - Does anybody know a way to inform the Designer that some fields are RO, so that it won't include them in the UPDATE statement? I precise that I need to get those fields in the SELECT, so I can't simply delete them from the Designer... 2 - If I have to make a customization of the code to bypass the default UPDATE clause and functions, can anybody give me a hand on how to do this? 3 - Any other idea to solve this, or any workaroud? Thanks to you all, guys. Pascal Chaprot:
All you need to do is run through the wizard and then go to the generated code and remove the column names from the update queries. If you are using Stored Procedures, you can just delete them from the proc, otherwise just change the generated code. Another approach is to remove them from the Select query and Add a column for each to your datatable, setting the expression to the same formula that you use in the database. This is preferable for a few reasons. 1- You don't have to modify the update commands 2-You don't have to pull over unnecessary data 3-If you update any of the columns that the computed ones are based on, right now the changes won't be reflected - however if you use an Expression column, they will be visible as soon as you make the change locally. This goes in to it in a little more depth http://www.knowdotnet.com/articles/expressions.html HTH, Bill Show quote "chaprot" <chap***@discussions.microsoft.com> wrote in message news:ABE96B61-433E-4BEA-8710-287A5A84B8A0@microsoft.com... > Hi, > > With VS 2005/NET 2.0, I add a datasource in my project, and the Dataset > Designer creates automaticaly the SELECT, INSERT, UPDATE and DELETE > functions/clauses. > > BUT the UPDATE include all the fields of the table, included some > read-only > or calculated fields. And thus, obviously, any attempt to update FAILS!!! > > 1 - Does anybody know a way to inform the Designer that some fields are > RO, > so that it won't include them in the UPDATE statement? I precise that I > need > to get those fields in the SELECT, so I can't simply delete them from the > Designer... > 2 - If I have to make a customization of the code to bypass the default > UPDATE clause and functions, can anybody give me a hand on how to do this? > 3 - Any other idea to solve this, or any workaroud? > > Thanks to you all, guys. > Pascal Hi Bill,
Thanks for your response. I will see what to do with the calculated fields, and read carefuly the article you propose. If I change the generated code (in MyDataset.Designer.cs) it may be overwritten when I make a modification in the DataSource Designer, right? So I suppose I have to create some overriden functions in a MyDataset.modified.cs or similar? The pity is that I'm losing all the advantage of the Designer, and of the automaticaly generated classes - as I will be obliged to manually monitor any change in the dataset on the table I've modified the code (in fact, I can only mantain the SELECT: UPDATE, INSERT and DELETE clauses and functions have to be modified). But why the hell does the designer NOT take into account a field marked as Read-Only? It's like a bug, as the generated code will NEVER work (except the SELECT) if there is a RO field - like an autonumber (except for the primary key, of course). Best regards, Pascal Show quote "W.G. Ryan - MVP" wrote: > Chaprot: > > All you need to do is run through the wizard and then go to the generated > code and remove the column names from the update queries. If you are using > Stored Procedures, you can just delete them from the proc, otherwise just > change the generated code. Another approach is to remove them from the > Select query and Add a column for each to your datatable, setting the > expression to the same formula that you use in the database. This is > preferable for a few reasons. 1- You don't have to modify the update > commands 2-You don't have to pull over unnecessary data 3-If you update any > of the columns that the computed ones are based on, right now the changes > won't be reflected - however if you use an Expression column, they will be > visible as soon as you make the change locally. This goes in to it in a > little more depth > > http://www.knowdotnet.com/articles/expressions.html > > HTH, > > Bill > "chaprot" <chap***@discussions.microsoft.com> wrote in message > news:ABE96B61-433E-4BEA-8710-287A5A84B8A0@microsoft.com... > > Hi, > > > > With VS 2005/NET 2.0, I add a datasource in my project, and the Dataset > > Designer creates automaticaly the SELECT, INSERT, UPDATE and DELETE > > functions/clauses. > > > > BUT the UPDATE include all the fields of the table, included some > > read-only > > or calculated fields. And thus, obviously, any attempt to update FAILS!!! > > > > 1 - Does anybody know a way to inform the Designer that some fields are > > RO, > > so that it won't include them in the UPDATE statement? I precise that I > > need > > to get those fields in the SELECT, so I can't simply delete them from the > > Designer... > > 2 - If I have to make a customization of the code to bypass the default > > UPDATE clause and functions, can anybody give me a hand on how to do this? > > 3 - Any other idea to solve this, or any workaroud? > > > > Thanks to you all, guys. > > Pascal > > > I HAVE IT !
In such a case, you have to create (with the Designer) the first SELECT clause WITHOUT the RO/calculated fields. Then the UPDATE, INSERT and DELETE clauses will be generated based on the SELECT fields. And - abracadabra ! - you create another (or others) SELECT clause with the Designer, to retrieve all the fields ! That's all ! Ouf !! No need to bypass the Designer or to customize th generated code. Great ! Pascal Show quote "chaprot" wrote: > Hi, > > With VS 2005/NET 2.0, I add a datasource in my project, and the Dataset > Designer creates automaticaly the SELECT, INSERT, UPDATE and DELETE > functions/clauses. > > BUT the UPDATE include all the fields of the table, included some read-only > or calculated fields. And thus, obviously, any attempt to update FAILS!!! > > 1 - Does anybody know a way to inform the Designer that some fields are RO, > so that it won't include them in the UPDATE statement? I precise that I need > to get those fields in the SELECT, so I can't simply delete them from the > Designer... > 2 - If I have to make a customization of the code to bypass the default > UPDATE clause and functions, can anybody give me a hand on how to do this? > 3 - Any other idea to solve this, or any workaroud? > > Thanks to you all, guys. > Pascal  |
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