ORA-00911: invalid character

I got ” ORA-00911: invalid character” error in Oracle database.

ORA-00911: invalid character

Details of error are as follows.

ORA-00911: invalid character

Cause: identifiers may not start with any ASCII character other than letters and numbers.
 $#_ are also allowed after the first character. Identifiers enclosed by doublequotes may
 contain any character other than a doublequote. Alternative quotes (q'#...#') cannot use
 spaces, tabs, or carriage returns as delimiters. For all other contexts, consult the SQL 
Language Reference Manual.

Action: None

invalid character

This ORA-00911 errors are related with the identifiers may not start with any ASCII character other than letters and numbers. $#_ are also allowed after the first character. Identifiers enclosed by doublequotes may contain any character other than a doublequote. Alternative quotes (q’#…#’) cannot use spaces, tabs, or carriage returns as delimiters.

Generally the semicolon (;), backtick (“) etc. from inside a query caused this error, you need to remove this from a query.

If you use a special character is added in an SQL statement with column name, you will get this error.

 when a special character is added in an SQL statement with column name
SQL> select name# from hr.employee;
select name# from hr.employee
*
ERROR at line 1:
ORA-00904: "name#": invalid identifier

Or If you use Acute` instead of quote’, you will get this error.

SQL> select * from hr.employee where name like `N%`;
select * from hr.employee where name like `N%`
*
ERROR at line 1:
ORA-00911: invalid character

Don’t forget to enclose by single quotes in where clause condition as follows.

SQL> select * from emp where name like A%;
select * from emp where name like A%
*
ERROR at line 1:
ORA-00911: invalid character

Or don’t use extra semicolon (;) at the end of the query.

SQL> select empno from emp;;
select empno from emp;
*
ERROR at line 1:
ORA-00911: invalid character

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