Document how to delete all records from all tables (#1510)

* adding content to crud page

* refactored, added tabs

* added some explainer text

* feedback changes

* Changed sqlite example

.vs/VSWorkspaceState.json

@@ -0,0 +1,6 @@
+{
+  "ExpandedNodes": [
+    ""
+  ],
+  "PreviewInSolutionExplorer": false
+}

content/200-concepts/100-components/02-prisma-client/030-crud.mdx

@@ -2,7 +2,7 @@
 title: 'CRUD'
 metaTitle: 'CRUD (Reference)'
 metaDescription: 'How to perform CRUD with Prisma Client.'
-tocDepth: 3
+tocDepth: 5
 ---
 
 <TopBlock>
@@ -246,7 +246,7 @@ const user = await prisma.user.findUnique({
 
 ### Get record by compound ID or unique identifier
 
-The following examples demonstrate how to retrieve records by a compound ID or unique identifier, defined by [`@@id`](../../../reference/api-reference/prisma-schema-reference#id-2) <span class="api"></span> or [`@@unique`](../../../reference/api-reference/prisma-schema-reference#unique-2) <span class="api"></span>. 
+The following examples demonstrate how to retrieve records by a compound ID or unique identifier, defined by [`@@id`](../../../reference/api-reference/prisma-schema-reference#id-2) <span class="api"></span> or [`@@unique`](../../../reference/api-reference/prisma-schema-reference#unique-2) <span class="api"></span>.
 
 The following Prisma model defines an compound ID:
 
@@ -267,9 +267,9 @@ const timePeriod = await prisma.timePeriod.findUnique({
   where: {
     year_quarter: {
       quarter: 4,
-      year: 2020
-    }
-  }
+      year: 2020,
+    },
+  },
 })
 ```
 
@@ -292,9 +292,9 @@ const timePeriod = await prisma.timePeriod.findUnique({
   where: {
     timePeriodId: {
       quarter: 4,
-      year: 2020
-    }
-  }
+      year: 2020,
+    },
+  },
 })
 ```
 
@@ -768,6 +768,76 @@ To resolve this error, you can:
   const transaction = await prisma.$transaction([deletePosts, deleteUser])
   ```
 
+### Delete all records from all tables
+
+Sometimes you want to remove all data from all tables but keep the actual tables. This can be particularly useful in a development environment. In the following two sections, you can learn how to delete all records from all tables with Prisma Client and with Prisma Migrate.
+
+The following examples show how to remove all data (including relations) from all tables in your PostgreSQL, SQLite and MySQL databases.
+
+The MySQL example uses a [`$transaction`](../../../guides/prisma-guides/prisma-client-transactions-guide/) to batch the queries together so that they are executed on the same connection.
+
+The SQLite example uses [`deleteMany`](../../../reference/api-reference/prisma-client-reference#deletemany) in combination with a [`$transaction`](../../../guides/prisma-guides/prisma-client-transactions-guide/) to synchronously delete each tables data.
+
+> **Note**: The SQLite `$transaction` performs a cascading delete on each models table so they have to be called in order.
+
+<TabbedContent tabs={[<FileWithIcon text="PostgreSQL" icon="database"/>, <FileWithIcon text="SQLite" icon="database"/>, <FileWithIcon text="MySQL" icon="database"/>]}>
+
+<tab>
+
+```ts
+// Special fast path to drop data from a postgres database.
+// This is an optimization which is particularly crucial in a unit testing context.
+// This code path takes milliseconds, vs ~7 seconds for a migrate reset + db push
+for (const { tablename } of await this.prisma
+  .$queryRaw`SELECT tablename FROM pg_tables WHERE schemaname='${this.dbSchemaName}'`) {
+  await this.prisma.$queryRaw`TRUNCATE TABLE \"${this.dbSchemaName}\".\"${tablename}\" CASCADE;`
+}
+for (const { relname } of await this.prisma
+  .$queryRaw`SELECT c.relname FROM pg_class AS c JOIN pg_namespace AS n ON c.relnamespace = n.oid WHERE c.relkind='S' AND n.nspname='${this.dbSchemaName}';`) {
+  await this.prisma
+    .$queryRaw`ALTER SEQUENCE \"${this.dbSchemaName}\".\"${relname}\" RESTART WITH 1;`
+}
+```
+
+</tab>
+
+<tab>
+
+```ts
+const deletePosts = prisma.post.deleteMany()
+const deleteProfile = prisma.profile.deleteMany()
+const deleteUsers = prisma.user.deleteMany()
+
+// The transaction runs synchronously so deleteUsers must run last.
+await prisma.$transaction([deleteProfile, deletePosts, deleteUsers])
+```
+
+</tab>
+
+<tab>
+
+```ts
+const [numberOfRowsDeleted] = await prisma.$transaction([
+  prisma.$executeRaw`SET FOREIGN_KEY_CHECKS = 0;`,
+  prisma.$executeRaw`TRUNCATE TABLE teams;`,
+  prisma.$executeRaw`TRUNCATE TABLE players;`,
+  prisma.$executeRaw`SET FOREIGN_KEY_CHECKS = 1;`,
+])
+```
+
+</tab>
+ 
+</TabbedContent>
+
+#### Deleting all records with Prisma Migrate
+
+If you use Prisma Migrate, you can use `migrate reset`, this will:
+
+1. Drop the database
+2. Create a new database
+3. Apply migrations
+4. Seed the database with data
+
 ## Advanced query examples
 
 ### Create a deeply nested tree of records