Add Check If Database And Schema Are Not In Sync as a Prisma TIL

prisma/check-if-database-and-schema-are-not-in-sync.md

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+# Check If Database And Schema Are Not In Sync
+
+The [`prisma migrate
+diff`](https://www.prisma.io/docs/orm/reference/prisma-cli-reference#migrate-diff)
+command is a versatile tool that can be used to check if there is a difference
+between two sources. In this case, we want to check if our database is in sync
+with the `schema.prisma` file for our project.
+
+If we have made changes to the schema file, but haven't yet migrated or pushed
+those changes to our local database, then we want to be notified of that
+mismatch.
+
+We'll point at the schema file with `--to-schema-datamodel` and at our local
+database with `--from-url`.
+
+```bash
+❯ npx prisma migrate diff \
+    --to-schema-datamodel ./prisma/schema.prisma \
+    --from-url mysql://root@localhost:3309/kcd-products
+
+[*] Changed the `User` table
+  [+] Added column `metadata`
+```
+
+In the case where there is a different, we see an output summary of the diff.
+
+Let's say we've applied our changes (`prisma db push`) to our local database.
+If we now run that same command again, we can see that no difference is
+detected and our database is in sync with our schema.
+
+```bash
+❯ npx prisma migrate diff \
+    --to-schema-datamodel ./prisma/schema.prisma \
+    --from-url mysql://root@localhost:3309/kcd-products
+
+No difference detected.
+```