Unable to find connection 'MyConnName' for object 'Web.config' in Table Adapter configure Properties

问题

I want to change the query in table adapter but it's not opening & throwing an error "Configure table Adapter Failed" & in property of connectionString it says "Unable to find connection 'ConnStringName' for object 'Web.config'. The connection string could not be found in application settings, or the data provider associated with the connection string could not be loaded"

回答1:

I have been looking for a solution for this problem for a long time. Thankfully I found a solution that worked for me.

1. Close the dataset window with the error.
2. Right click the dataset in the solution explorer.
3. Select “Open with…” from the context menu.
4. Select “Source Code (Text) Editor” from the list and press the “OK” button.

Near the top of the file, you’ll see a element with several elements within it. Most datasets should only have one element. If you are having trouble like I’ve described above, you’ll have at least two and one will be incorrect. Delete it or otherwise fix it, save the file and reopen normally.

This is the page where I found it out. See the complete answer here

回答2:

Seems like there no ConnStringName parameter in connectionString section of Web.config

<connectionStrings> 
    <add name="ConnStringName" providerName="" connectionString=""/>
</connectionStrings>

Updated: The problem is in missing reference to System.Data.OracleClient. To solve this just add reference on missing provider.

来源：https://stackoverflow.com/questions/40101459/unable-to-find-connection-myconnname-for-object-web-config-in-table-adapter