Oracle Database Errors or Warnings from Error ORA-02251 to ORA-02260
ORA-02251: subquery not allowed here
Cause: Subquery is not allowed here in the statement.
Action: Remove the subquery from the statement.
ORA-02252: check constraint condition not properly ended
Cause: The specified search condition for the check constraint is not properly ended.
Action: End the condition properly.
ORA-02253: constraint specification not allowed here
Cause: Constraint specification is not allowed here in the statement.
Action: Remove the constraint specification from the statement.
ORA-02254: DEFAULT <expression> not allowed here
Cause: Default value expression is not allowed for the column here in the statement.
Action: Remove the default value expression from the statement.
ORA-02255: obsolete 7.1.5
Cause: Was that defaults must not conflict with not null constraints
ORA-02256: number of referencing columns must match referenced columns
Cause: The number of columns in the foreign-key referencing list is not equal to the number of columns in the referenced list.
Action: Make sure that the referencing columns match the referenced columns.
ORA-02257: maximum number of columns exceeded
Cause: The number of columns in the key list exceeds the maximum number.
Action: Reduce the number columns in the list.
ORA-02258: duplicate or conflicting NULL and/or NOT NULL specifications
Action: Remove the duplicate or conflicting specification.
ORA-02259: duplicate UNIQUE/PRIMARY KEY specifications
Action: Remove the duplicate specification.
ORA-02260: table can have only one primary key
Action: Remove the extra primary key.
Above are list of Oracle Database Errors or Warnings from Error ORA-02251 to ORA-02260 received while performing certain operation against Oracle Database or related products.
What are Oracle Database Error Messages?
Oracle Error Messages may be returned while using products which are part of Oracle Database. Each Oracle Database Error or Warning Message mentioned above contains the Warning or Error Message Statement, a short explanation of the probable causes of the Error message, and a recommended action.
Hope this was helpful.
Information about Oracle Database Error Messages or Warning Messages on Windows and Linux Operating Systems.