I keep receiving an error while trying to load data to Azure DataBase using Azure Function - sql-server

Question

I created an Azure Function to load data from Eudonet CRM to my Azure SQL Database. I have two databases :
named Datawarehouse
named Datawarehouse-Dev
Both databases are identical and are in the same server.
When I load data directly to "Datawarehouse" the copy works fine, but when I change the database name to "Datawarehouse-Dev", I receive the following errors :
Index #0 Message: Login failed for user 'AzureFunction'. LineNumber: 65536 Source: Core .Net SqlClient Data Provider Procedure: Error Code:18456
-- Sql server error. If error code <17: => check sql transac code (user error). Else: => software or hardware errors (check availability of database)
Login failed for user 'AzureFunction'.
If anyone has an idea on where the problem could come from I would be very grateful and I also don't understand why there is an authentification error since they're both in the same server and are accessed with the same user/password.
Thanks in advance

Answer 1

Though #adnane already resolved the issue after using the connection string directly into Function application setting instead of storing it into Vault. This approach might compromise the application security because using connection string directly might expose it to unauthorized person.
Azure Key Vault is a good place to keep our application credentials in a secured and centralized manner. Moving the secrets to Key Vault becomes even more important while our Azure solution is growing.
In case, if anyone still looking for the solution by storing the connection string in Azure Key Vault and then using it in the Function, please follow the below steps.
Firstly, open the Azure Key Vault service and from the Settings menu select Access policies. Then select + Add new access policy.
Then choose Select principal and search for the name of the Function App as shown in below example.
Once your principal is selected choose the Secret permissions menu. In this case, we’ll only need to get the secret from the Key Vault (concretely read our connection string). Therefore, check Get permission only and then select OK.
At the end, select Save to store the new functionapp-demo-mw access policy.
ADDING SECRET TO AZURE KEY VAULT
Adding a secret to Azure Key Vault is straightforward. From the Key Vault, Settings menu select Secrets and then select + Generate/Import secret.
For Key Vault secret two values are required – name and the value. In this case we’ve called our secret OrderManagementDbConnectionString and as a value we put our SQL Database connection string. Select Create to save the secret.
By default, the secret is Enabled so it’s ready to use. Once the secret is created, we’ll need to get its URI (a unique location identifying the secret). Go to the Settings menu and select Secrets. We’ll find here our recently added secret (OrderManagementDbConnectionString). Select the secret and we’ll see it’s the only version in the list.
Select the current version of secret and copy its secret identifier. The identifier is an URI with pattern : https://<url_of_the_key_value>/<secret_name>/<secret_version>.
GETTING SECRET FROM KEY VAULT IN AZURE FUNCTION APP
Go back to the Azure Function App (functionapp-demo-mw) and on the Overview tab, select Configuration in Configured featured section.
Well, Select + New application settings. Put a name that describes the new setting (we’ve put OrderManagementConnectionString). At the end of the last year, Microsoft has added an option of sourcing Key Vault secrets directly from App Settings. This simplifies a lot the way how the secrets were used before. So, set the value of the setting to a secret reference in the following format:
#Microsoft.KeyVault(SecretUri=**secret_uri_with_version**)
We just need to replace secret_uri_with_version with the value we’ve previously copied from the secret in Azure Key Vault.
In Azure Function, you’ll just retrieve the value from the application settings and work with it the same way as it was directly a connection string stored in application settings.
// get value from appliction settings
var connectionString = Environment.GetEnvironmentVariable("OrderManagementConnectionString");
// create connection
SqlConnection connection = new SqlConnection(connectionString);