The new command text returns data with schema different from the schema of the main query. Check your query's command text if this is not desired

Question

The new command text returns data with schema different from the schema of the main query. Check your query's command text if this is not desired.

I am getings this warning, when ever i add a query in a Strongly Typed DataSet which returns a single column

Ex

`SELECT DISTINCT Building
 FROM            Room
 ORDER BY Building

when i give this query it will show me a warning.

Because warning leads to a constraint error when ever i call the same function in a windows form

Answer 1

You should configure this query in your TableAdapter to return a scalar(single) value instead of returning rows. Otherwise the TableAdapter tries to apply the same schema as in your main query.

• http://msdn.microsoft.com/en-us/library/ms233822%28v=vs.100%29.aspx
• http://msdn.microsoft.com/en-us/library/ms171907.aspx

According to your comment:

"In addition to the standard functionality of a DataAdapter, TableAdapters provide additional typed methods that encapsulate queries that share a common schema with the associated typed DataTable. In other words, you can have as many queries as you want on a TableAdapter as long as they return data that conforms to the same schema."

• http://msdn.microsoft.com/en-us/library/bz9tthwx%28VS.80%29.aspx

You either have to create another TableAdapter with different schema(one column) or you keep returning all columns of your main-query and pick that column that you need(f.e. with the DisplayMember property of a ComboBox).

Answer 2

When looking for DISTINCT values, the schema will differ from the MAIN query. The MAIN query usually will envelop the entire structure for hooking up to forms. I (for example) want DISTINCT values from all the records to populate a combo box. This is NOT possible due to schema errors. To suggest the nobody would need to use DISCTINCT values to populate a combo or listbox would be ignorant.

Bottom line, need to create a new TableAdapter, or loop throught the dataset and populate your combo with unique value.

Being able to add multiple queries (Either FillBy, or GetBy) to return rows or single values without have to worry about the schema would solve alot of issues.