# Logging (Prisma ORM v7) (/docs/orm/v7/prisma-client/observability-and-logging/logging)

> For the complete Prisma documentation index, see [llms.txt](https://www.prisma.io/docs/llms.txt). A markdown version of any docs page is available by appending `.md` to its URL.

Learn how to configure Prisma Client to log the raw SQL queries it sends to the database and other information

Location: ORM > v7 > Prisma Client > Observability and Logging > Logging

Use the `PrismaClient` [`log`](https://www.prisma.io/docs/orm/v7/reference/prisma-client-reference#log) parameter to configure [log levels](https://www.prisma.io/docs/orm/v7/reference/prisma-client-reference#log-levels) , including warnings, errors, and information about the queries sent to the database.

Prisma Client supports two types of logging:

* Logging to [stdout](https://en.wikipedia.org/wiki/Standard_streams) (default)
* Event-based logging (use [`$on()`](https://www.prisma.io/docs/orm/v7/reference/prisma-client-reference#on) method to [subscribe to events](#event-based-logging))

> [!NOTE]
> You can also use the `DEBUG` environment variable to enable debugging output in Prisma Client. See [Debugging](https://www.prisma.io/docs/orm/v7/prisma-client/debugging-and-troubleshooting/debugging) for more information.

> [!NOTE]
> If you want a detailed insight into your Prisma Client's performance at the level of individual operations, see [Tracing](https://www.prisma.io/docs/orm/v7/prisma-client/observability-and-logging/opentelemetry-tracing).

## Log to stdout [#log-to-stdout]

The simplest way to print *all* log levels to stdout is to pass in an array `LogLevel` objects:

```ts
const prisma = new PrismaClient({
  log: ["query", "info", "warn", "error"],
});
```

This is the short form of passing in an array of `LogDefinition` objects where the value of `emit` is always `stdout`:

```ts
const prisma = new PrismaClient({
  log: [
    {
      emit: "stdout",
      level: "query",
    },
    {
      emit: "stdout",
      level: "error",
    },
    {
      emit: "stdout",
      level: "info",
    },
    {
      emit: "stdout",
      level: "warn",
    },
  ],
});
```

## Event-based logging [#event-based-logging]

To use event-based logging:

1. Set `emit` to `event` for a specific log level, such as query
2. Use the `$on()` method to subscribe to the event

The following example subscribes to all `query` events and write the `duration` and `query` to console:

  

#### Relational databases

```ts highlight=4,5,22-26;normal 
const prisma = new PrismaClient({
  log: [
    {
      emit: "event",
      level: "query",
    },
    {
      emit: "stdout",
      level: "error",
    },
    {
      emit: "stdout",
      level: "info",
    },
    {
      emit: "stdout",
      level: "warn",
    },
  ],
});

prisma.$on("query", (e) => {
  console.log("Query: " + e.query);
  console.log("Params: " + e.params);
  console.log("Duration: " + e.duration + "ms");
});
```

```sql
Query: SELECT "public"."User"."id", "public"."User"."email", "public"."User"."name" FROM "public"."User" WHERE 1=1 OFFSET $1
Params: [0]
Duration: 3ms
Query: SELECT "public"."Post"."id", "public"."Post"."title", "public"."Post"."authorId" FROM "public"."Post" WHERE "public"."Post"."authorId" IN ($1,$2,$3,$4) OFFSET $5
Params: [2, 7, 18, 29]
Duration: 2ms
```

  

#### MongoDB

```ts highlight=4,5,22-25;normal 
const prisma = new PrismaClient({
  log: [
    {
      emit: "event",
      level: "query",
    },
    {
      emit: "stdout",
      level: "error",
    },
    {
      emit: "stdout",
      level: "info",
    },
    {
      emit: "stdout",
      level: "warn",
    },
  ],
});

prisma.$on("query", (e) => {
  console.log("Query: " + e.query);
});
```

```bash
Query: db.User.aggregate([ { $project: { _id: 1, email: 1, name: 1, }, }, ])
Query: db.Post.aggregate([ { $match: { userId: { $in: [ "622f0bbbdf635a42016ee325", ], }, }, }, { $project: { _id: 1, slug: 1, title: 1, body: 1, userId: 1, }, }, ])
```

The exact [event (`e`) type and the properties available](https://www.prisma.io/docs/orm/v7/reference/prisma-client-reference#event-types) depends on the log level.

## Related pages

- [`OpenTelemetry tracing`](https://www.prisma.io/docs/orm/v7/prisma-client/observability-and-logging/opentelemetry-tracing): Diagnose application performance with detailed traces of each query
- [`SQL comments`](https://www.prisma.io/docs/orm/v7/prisma-client/observability-and-logging/sql-comments): Add metadata to your SQL queries as comments for improved observability, debugging, and tracing