Error map
Unknown collation MySQL ERROR 1273 (HY000): Unknown collation: 'utf8mb4_0900_ai_ci'
MySQL · layer 5, Data
Centre: this error. First ring: errors it is linked with (9). 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 (9)
MySQL ERROR 1227 (42000): Access denied; you need (at least one of) the SUPER privilege(s) for this operation
The import or statement needs SUPER/SYSTEM_VARIABLES_ADMIN — typical with dumps containing DEFINER clauses or SET GLOBAL on manag…
MySQL ERROR 1267 (HY000): Illegal mix of collations (utf8mb4_unicode_ci,IMPLICIT) and (utf8mb4_0900_ai_ci,IMPLICIT) for operation '='
Two strings with different collations were compared or joined.
MySQL ERROR 1046 (3D000): No database selected
A query referenced tables without a database selected (no USE and no db in the connection).
MySQL ERROR 1071 (42000): Specified key was too long; max key length is 767 bytes
An index on a VARCHAR is too long for the row format — classic with utf8mb4 VARCHAR(255) on MySQL 5.6/MariaDB 10.1.
MySQL ERROR 1366: Incorrect string value: '\xF0\x9F\x98\x80' for column
The text contains characters (usually emoji) that the column’s character set can’t store — the column or connection is `utf8`/`ut…
TypeError: x is not a constructor
new was used with something that isn’t a class/constructor — usually a wrong import.
MySQL ERROR 1153 (08S01): Got a packet bigger than 'max_allowed_packet' bytes
A single statement or row exceeded max_allowed_packet — big BLOBs, huge INSERTs or large dump lines.
Go: declared and not used: x / "fmt" imported and not used
Go refuses to compile code with unused local variables or unused imports.
ReferenceError: Cannot access 'x' before initialization
A let/const/class was used before its declaration line ran (temporal dead zone) — often a circular import.
Two steps away (27)
MySQL ERROR 1045 (28000): Access denied for user
MySQL rejected the login — wrong password, wrong user/host combination, or the user doesn’t exist.
MySQL ERROR 1044 (42000): Access denied for user to database
The login succeeded, but the user has no privileges on the database you’re using.
MySQL ERROR 1130 (HY000): Host 'x' is not allowed to connect to this MySQL server
No MySQL account exists for the host you’re connecting from.
Column reference is ambiguous / Column 'id' in field list is ambiguous (MySQL 1052)
A column name exists in more than one joined table, so the database doesn’t know which one you mean.
ERROR: missing FROM-clause entry for table "x"
The query references a table/alias that isn’t in the FROM clause (or uses the wrong alias).
MySQL ERROR 1066 (42000): Not unique table/alias: 'x'
The same table or alias appears twice in a FROM/JOIN without distinct aliases.
OAuth Error: redirect_uri_mismatch
The redirect URI in your OAuth request doesn’t exactly match one registered for the client in the provider’s console.
hint: You have divergent branches and need to specify how to reconcile them.
Git 2.27+ asks you to choose merge, rebase or fast-forward-only when local and remote both have new commits.
error: gpg failed to sign the data — fatal: failed to write commit object
Commit signing is enabled but GPG couldn’t sign — no TTY for the passphrase, wrong key, or agent not running.
MySQL ERROR 1005 (HY000): Can't create table (errno: 150 "Foreign key constraint is incorrectly formed")
A foreign key definition is invalid — the referenced column’s type, index or charset doesn’t match.
MySQL ERROR 1007 (HY000): Can't create database 'x'; database exists
CREATE DATABASE ran for a database that already exists.
MySQL ERROR 1008 (HY000): Can't drop database 'x'; database doesn't exist
DROP DATABASE targeted a database that isn’t there.
MySQL ERROR 1064 (42000): You have an error in your SQL syntax
MySQL couldn’t parse the query. The text after “near” shows where parsing failed.
MySQL ERROR 1406: Data too long for column
The value is longer than the column allows (e.g. 300 characters into VARCHAR(255)), and strict mode rejects it instead of truncat…
MySQL ERROR 1366 (HY000): Incorrect integer value: '' for column 'x' at row 1
An empty string or non-numeric text was inserted into an INT column under strict mode.
TypeError: x is not a function
You called something as a function, but its value is not a function (it’s undefined, a string, an object…).
TypeError: Router.use() requires a middleware function but got a Object
app.use()/router.use() received an object instead of a function — usually a router module that wasn’t exported.
ERROR: invalid byte sequence for encoding "UTF8": 0x00
Text contained bytes invalid in UTF-8 — often a NUL byte (0x00) or Latin-1/Windows-1252 data.
MySQL ERROR 2006 (HY000): MySQL server has gone away
The connection to MySQL was closed — usually by a timeout or a packet larger than `max_allowed_packet`.
MySQL ERROR 1049 (42000): Unknown database 'x'
The database named in the connection doesn’t exist on that server.
API Error: Invalid or unsupported API version
The API version you requested — in the URL, a header or the SDK config — doesn’t exist or has been retired.
ImportError: cannot import name 'x' from 'y'
The module was found, but the name you’re importing from it doesn’t exist — usually a version change or a circular import.
Error: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined
JSX referenced a component that is undefined — almost always a default/named import mismatch.
error CS0246: The type or namespace name 'X' could not be found (are you missing a using directive or an assembly reference?)
The compiler doesn’t know the type — missing using, missing NuGet package/project reference, or a target framework mismatch.
ReferenceError: x is not defined
Code refers to a variable or function name that doesn’t exist in the current scope.
NameError: name 'x' is not defined
Python doesn’t know the name — it was never assigned/imported in this scope, or it’s misspelled.
SyntaxError: Identifier 'x' has already been declared
The same let/const/class name was declared twice in the same scope.
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