Database Error Encyclopedia
Instant answers for 15+ common database errors across MySQL, PostgreSQL, SQL Server, and Oracle. Each entry includes root causes, step-by-step fixes, and prevention tips.
15+
Error Codes
4
Databases Covered
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Free
MySQL Errors
5 errors documentedMySQL 1045
Access Denied for User
MySQL Error 1045 occurs when a client attempts to connect with credentials that the MySQL server rej...
MySQL 1064
SQL Syntax Error
MySQL Error 1064 indicates a syntax error in the SQL statement. MySQL's parser encountered a token i...
MySQL 1062
Duplicate Entry for Key
MySQL Error 1062 occurs when an INSERT or UPDATE attempts to add a value that violates a UNIQUE or P...
MySQL 1146
Table Doesn't Exist
MySQL Error 1146 occurs when a SQL statement references a table that does not exist in the current d...
MySQL 1452
Cannot Add or Update Child Row: FK Constraint Fails
MySQL Error 1452 occurs when an INSERT or UPDATE on a child table tries to set a foreign key value t...
PostgreSQL Errors
5 errors documentedPostgreSQL 08001
Connection Failure / Unable to Connect
PostgreSQL SQLSTATE 08001 indicates the client could not establish a connection to the PostgreSQL se...
PostgreSQL 42601
Syntax Error
PostgreSQL SQLSTATE 42601 indicates a SQL syntax error. PostgreSQL's error messages are among the mo...
PostgreSQL 23505
Unique Violation
PostgreSQL SQLSTATE 23505 occurs when an INSERT or UPDATE violates a UNIQUE or PRIMARY KEY constrain...
PostgreSQL 28P01
Invalid Password / Authentication Failed
PostgreSQL SQLSTATE 28P01 indicates that the client provided the correct username but the wrong pass...
PostgreSQL 42703
Column Does Not Exist
PostgreSQL SQLSTATE 42703 occurs when a SQL statement references a column that does not exist in the...
SQL Server Errors
3 errors documentedSQL Server 18456
Login Failed for User
SQL Server Error 18456 is an authentication failure. SQL Server's error log contains the critical 'S...
SQL Server 208
Invalid Object Name
SQL Server Error 208 occurs when a query references a table, view, stored procedure, or other databa...
SQL Server 1205
Transaction Deadlock Victim
SQL Server Error 1205 occurs when the SQL Server deadlock monitor detects two transactions that are ...
Oracle Errors
2 errors documentedOracle 01017
Invalid Username/Password; Logon Denied
Oracle ORA-01017 is an authentication failure — the provided username/password combination was rejec...
Oracle 00942
Table or View Does Not Exist
Oracle ORA-00942 occurs when a SQL statement references a table or view that does not exist in the c...
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