feat: fetch database connections (#4813)

Closes #4757

---------

Co-authored-by: Thomas Trompette <thomast@twenty.com>

packages/twenty-front/src/modules/databases/graphql/queries/findManyDatabaseConnections.ts

@@ -0,0 +1,14 @@
+import { gql } from '@apollo/client';
+
+export const GET_MANY_DATABASE_CONNECTIONS = gql`
+  query GetManyDatabaseConnections($input: RemoteServerTypeInput!) {
+    findManyRemoteServersByType(input: $input) {
+      id
+      createdAt
+      foreignDataWrapperId
+      foreignDataWrapperOptions
+      foreignDataWrapperType
+      updatedAt
+    }
+  }
+`;

packages/twenty-front/src/modules/databases/hooks/useGetDatabaseConnections.ts

@@ -0,0 +1,37 @@
+import { useQuery } from '@apollo/client';
+
+import { GET_MANY_DATABASE_CONNECTIONS } from '@/databases/graphql/queries/findManyDatabaseConnections';
+import { useApolloMetadataClient } from '@/object-metadata/hooks/useApolloMetadataClient';
+import {
+  GetManyDatabaseConnectionsQuery,
+  GetManyDatabaseConnectionsQueryVariables,
+} from '~/generated-metadata/graphql';
+
+type UseGetDatabaseConnectionsParams = {
+  databaseKey: string;
+  skip?: boolean;
+};
+
+export const useGetDatabaseConnections = ({
+  databaseKey,
+  skip,
+}: UseGetDatabaseConnectionsParams) => {
+  const apolloMetadataClient = useApolloMetadataClient();
+
+  const { data } = useQuery<
+    GetManyDatabaseConnectionsQuery,
+    GetManyDatabaseConnectionsQueryVariables
+  >(GET_MANY_DATABASE_CONNECTIONS, {
+    client: apolloMetadataClient ?? undefined,
+    skip: skip || !apolloMetadataClient || databaseKey !== 'postgresql',
+    variables: {
+      input: {
+        foreignDataWrapperType: 'postgres_fdw',
+      },
+    },
+  });
+
+  return {
+    connections: data?.findManyRemoteServersByType || [],
+  };
+};