Error map
E11000 duplicate key MongoServerError: E11000 duplicate key error collection: db.users index: email_1 dup key
Node.js · layer 4, Application & API
Centre: this error. First ring: errors it is linked with (10). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (10)
MySQL ERROR 1062 (23000): Duplicate entry for key
An INSERT/UPDATE would create a duplicate value in a PRIMARY or UNIQUE key.
CastError: Cast to ObjectId failed for value "x" (type string) at path "_id"
A value that isn’t a valid 24-hex-character ObjectId was used in an _id query.
ValidationError: User validation failed: email: Path `email` is required.
A document failed Mongoose schema validation before saving.
MongooseServerSelectionError: connect ECONNREFUSED 127.0.0.1:27017
The MongoDB driver couldn’t find a reachable server for the connection string.
DbUpdateException: An error occurred while saving the entity changes. See the inner exception for details.
SaveChanges failed in the database; the inner exception (SqlException/PostgresException) has the real reason — constraint violati…
MongoDB: MongoServerError: Document failed validation (code 121)
The collection has a JSON Schema validator and the inserted/updated document doesn’t satisfy it.
PostgreSQL: ERROR: duplicate key value violates unique constraint
An INSERT/UPDATE would create a duplicate in a UNIQUE or PRIMARY KEY column — or the id sequence is behind the existing data.
MongooseError: Operation `users.find()` buffering timed out after 10000ms
Mongoose queued a query waiting for a connection that never opened.
API Error: Resource already exists (ALREADY_EXISTS / resource_already_exists / 409)
The create request was refused because an object with the same unique identity — name, email, external ID — already exists.
PrismaClientKnownRequestError P2002: Unique constraint failed on the fields: (`email`)
A Prisma create/update violated a unique constraint.
Two steps away (26)
MySQL ERROR 1452: Cannot add or update a child row: a foreign key constraint fails
You inserted/updated a row whose foreign key value doesn’t exist in the referenced parent table.
Deadlock found when trying to get lock; try restarting transaction
Two transactions waited on each other’s locks; the database killed one so the other could continue.
HTTP 409 Conflict
The request conflicts with the current state of the resource — e.g. a duplicate or an edit based on an outdated version.
HTTP 422 Unprocessable Content
The request is well-formed, but the data fails validation (e.g. invalid email, missing required field).
java.lang.NumberFormatException: For input string: "x"
A string couldn’t be parsed as a number — it’s empty, has spaces/commas, is too large, or isn’t numeric.
java.lang.IllegalArgumentException
A method rejected an argument value as invalid.
Express: req.body is undefined / {} (body parser missing)
Express didn’t parse the request body because no body-parsing middleware matched the request’s Content-Type.
API Error: Invalid type — expected integer, received string
A request field has the wrong data type — a string where the API expects a number, a number where it expects a boolean, an object…
API Error: Invalid parameter value — must be one of the allowed values / out of range
The field has the right type but a value the API doesn’t allow — not in the list of accepted options, too small or large, too lon…
Error: connect ECONNREFUSED 127.0.0.1:5432
Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.
Error: P1001: Can't reach database server at `host`:`5432`
Prisma couldn’t connect to the database in DATABASE_URL.
SequelizeConnectionRefusedError: connect ECONNREFUSED 127.0.0.1:5432
Sequelize couldn’t connect to the database server.
JsonException: A possible object cycle was detected
System.Text.Json found a reference loop (e.g. Order → Customer → Orders → …) while serialising, usually from EF Core navigation p…
org.hibernate.exception.ConstraintViolationException: could not execute statement
The database rejected an insert/update because of a constraint (unique, foreign key, not null).
MySQL ERROR 1022 (23000): Can't write; duplicate key in table
An ALTER/CREATE produced a duplicate key or constraint name — often a foreign key name that already exists in the database.
MySQL ERROR 1146 (42S02): Table 'db.table' doesn't exist
The query references a table that MySQL can’t find in that database.
MySQL ERROR 1054 (42S22): Unknown column in 'field list'
The query references a column that doesn’t exist in the table (or an unquoted string being read as a column).
PostgreSQL: ERROR: relation "x" does not exist
The table/view isn’t found — missing migration, wrong schema, or a case-sensitive quoted name.
ERROR: null value in column "x" of relation "y" violates not-null constraint
An INSERT/UPDATE put NULL into a NOT NULL column.
ERROR: insert or update on table "x" violates foreign key constraint "fk" — Key (user_id)=(5) is not present in table "users"
The row references a parent row that doesn’t exist.
ERROR: update or delete on table "users" violates foreign key constraint on table "orders" — Key (id)=(5) is still referenced
You tried to delete a row that other rows still reference.
HikariPool-1 - Connection is not available, request timed out after 30000ms
The connection pool was exhausted — all connections were busy for 30 seconds.
MySQL ERROR 1048 (23000): Column 'x' cannot be null
An INSERT/UPDATE put NULL into a NOT NULL column.
MySQL ERROR 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails
You tried to delete/update a row that other rows still reference.
ERROR: there is no unique or exclusion constraint matching the ON CONFLICT specification
INSERT … ON CONFLICT (cols) names columns that don’t have a matching unique index/constraint.
Error: @prisma/client did not initialize yet. Please run "prisma generate"
The generated Prisma Client is missing or out of date.
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