Trouble Creating Stored Procedure Insert Statement in .NET with VisualStudio/TableAdapter

Question

I am trying to create a TableAdapter for a typed DataSet for my persistence layer. I am going to read information from a file, and then insert that into the database.

• The information in the file is a SerialNumber, VOCLevel, Date, Time, Accuracy.
• The information I need to insert is MonitorID, VOCLevel, Date, Time, Accuracy.

The SerialNumber is related to a MonitorID in the database. The insert I am trying to write in the TableAdapter Config Wizard in Visual Studio is:

INSERT INTO VOCReading (MonitorID, Level, Date, Time, Accuracy)
VALUES( (SELECT MonitorID FROM Monitor WHERE SerialNumber= @SerialNumber), @Level, @Date, @Time, @Accuracy)

The error I get is

Must declare the scalar variable '@SerialNumber'

How can I get around this? SerialNumber is in the Monitor table, but the table I need to insert into is VOCReading.

Answer 1

The INSERT command comes in two flavors:

(1) either you have all your values available, as literals or SQL Server variables - in that case, you can use the INSERT .. VALUES() approach:

INSERT INTO dbo.YourTable(Col1, Col2, ...., ColN)
VALUES(Value1, Value2, @Variable3, @Variable4, ...., ValueN)

Note: I would recommend to always explicitly specify the list of column to insert data into - that way, you won't have any nasty surprises if suddenly your table has an extra column, or if your tables has an IDENTITY or computed column. Yes - it's a tiny bit more work - once - but then you have your INSERT statement as solid as it can be and you won't have to constantly fiddle around with it if your table changes.

(2) if you don't have all your values as literals and/or variables, but instead you want to rely on another table, multiple tables, or views, to provide the values, then you can use the INSERT ... SELECT ... approach:

INSERT INTO dbo.YourTable(Col1, Col2, ...., ColN)
   SELECT
       SourceColumn1, SourceColumn2, @Variable3, @Variable4, ...., SourceColumnN
   FROM
       dbo.YourProvidingTableOrView

Here, you must define exactly as many items in the SELECT as your INSERT expects - and those can be columns from the table(s) (or view(s)), or those can be literals or variables. Again: explicitly provide the list of columns to insert into - see above.

You can use one or the other - but you cannot mix the two - you cannot use VALUES(...) and then have a SELECT query in the middle of your list of values - pick one of the two - stick with it.

So in your case, you'd have to use the INSERT .. SELECT approach since you need to select something from a table - you cannot use the VALUES approach:

INSERT INTO VOCReading (MonitorID, Level, Date, Time, Accuracy)
    SELECT MonitorID, @Level, @Date, @Time, @Accuracy
    FROM Monitor 
    WHERE SerialNumber = @SerialNumber