Update docs on binding behavior when columns change. (#1183)

Author: MaddyDev

README.md

@@ -57,6 +57,7 @@ Below is a list of common issues that users may run into when using the SQL Bind
 - **By Design:** Output bindings against tables with columns of data types `NTEXT`, `TEXT`, or `IMAGE` are not supported and data upserts will fail. These types [will be removed](https://docs.microsoft.com/sql/t-sql/data-types/ntext-text-and-image-transact-sql) in a future version of SQL Server and are not compatible with the `OPENJSON` function used by this Azure Functions binding.
 - **By Design:** .NET In-Proc output bindings against tables with columns of data types `DATE`, `DATETIME`, `DATETIME2`, `DATETIMEOFFSET`, or `SMALLDATETIME` will convert values for those columns to ISO8061 format ("yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fffZ") before upsertion. This does not happen for functions written in C# out-of-proc or other languages.
 - **By Design:** Output bindings execution order is not deterministic ([azure-webjobs-sdk#1025](https://github.com/Azure/azure-webjobs-sdk/issues/1025)) and so the order that data is upserted is not guaranteed. This can be problematic if, for example, you upsert rows to two separate tables with one having a foreign key reference to another. The upsert will fail if the dependent table does its upsert first.
+- **By Design:** Output bindings will exhibit undefined behavior if the SQL table schema gets modified while the user application is running, for example, if a column is added, renamed or deleted or if the primary key is modified or deleted. In such cases, restarting the application should help resolve any errors.
 
     Some options for working around this :
   - Have multiple functions, with dependent functions being triggered by the initial functions (through a trigger binding or other such method)