C#•3y ago

❔ Host Can't be Null error when trying to run db migration using postgres

I'm pretty sure this is a id10t issue here. I have added appsettings.json and appsettings.Development.json in all of my directories because I think my program is not referencing the right appsettings.json, however when I did I am still getting the error.

KrisOP•8/6/23, 4:07 PM

My appsettings and appsettings.Development.json have the same content

KrisOP•8/6/23, 4:07 PM

undisputed world champions 🍉•8/6/23, 4:16 PM

it seems like you don't have a appsettings.json in your Web-project
that's the one that counts
not sure if it makes sense having appsettings.json in library-project catthinking

KrisOP•8/6/23, 4:37 PM

Idk if this helps but I am running

dotnet ef database update

dotnet ef database update

in my Helpers directory. That's where my Data Context.cs is. I readded appsettings.json and apsettings.Development.json in the Web ( realized it's missing in that screenshot ) and am getting the same results

KrisOP•8/6/23, 4:37 PM

This is my file structure @icebear42

KrisOP•8/6/23, 4:39 PM

I also tried adding the connection string directly in Program.cs via below and still getting the same error

phaseshift•8/6/23, 4:42 PM

I think since you split the context out from the web host you need to specify extra stuff in the command

phaseshift•8/6/23, 4:43 PM

e.g. if you run from the the context location you need to specify the other project (-p flag)

phaseshift•8/6/23, 4:43 PM

vice versa would need the -c flag to specify the name of the context as well?

phaseshift•8/6/23, 4:43 PM

But not really sure - just reading chat gpt

KrisOP•8/6/23, 4:43 PM

Ahh will try that

KrisOP•8/6/23, 4:46 PM

I threw up on the verbose flag this is giving me clues

KrisOP•8/6/23, 4:55 PM

Adding the connection string directly into the method worked ughh.. The mystery continues!

KrisOP•8/6/23, 4:56 PM

The connection string is right, I think the location of the appconfig is throwng it off

blueberriesiftheywerecats•8/7/23, 6:32 AM

You dont need OnConfiguring, you need to pass through ctor smth like IDbContextOptions/IDbContextOptionsBuilder(i forgor)

Accord•8/8/23, 6:41 AM

Was this issue resolved? If so, run

/close

/close

- otherwise I will mark this as stale and this post will be archived until there is new activity.

Stage•9/23/24, 12:48 AM

Reviving this just to tell anyone who stumbles across this like I did: The only thing that fixed this for me was to remove my design-time DbContextFactory implementation, which had a default constructor. A tell-tale sign you have the same issue is to run

dotnet ef database update

dotnet ef database update

with a valid connection string as a CLI argument: --connection "<connection str>"--connection "<connection str>". The key is to get rid of any design-time factories / ways a

DbContext

DbContext

can be instantiated without valid credentials. Hope this helps! (This assumes you have an otherwise valid configuration etc.)

❔ Host Can't be Null error when trying to run db migration using postgres

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