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Logging

Use the PrismaClient log parameter to configure log levels , including warnings, errors, and information about the queries sent to the database.

Prisma supports two types of logging:

You can also use the DEBUG environment variable to enable debugging output in Prisma Client. See Debugging for more information.

If you want a detailed insight into your Prisma Client's performance at the level of individual operations, see Tracing.

Log to stdout​

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

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:

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

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
MongoDB

The exact event (e) type and the properties available depends on the log level.