ORA-00900: invalid SQL statement tips

Oracle offers information regarding ORA-00900, when it occurs while attempting to use a database link.  Many users find that they are encountering ORA-00900 as they attempt to query fields which may have worked before 2000. 

To resolve ORA-00900, on the local database, try altering your init.ora parameter NLS_DATE_FORMAT, then use double quotes (instead of single) around the value.  For example:

NLS_DATE_FORMAT = "DD-MON-YYYY"

The next step in resolving ORA-00900 is to restart the database.

If you want to instead alter the parameter in the session, you can try:

SQL> alter session set NLS_DATE_FORMAT = "DD-MON-YYYY";

The reason ORA-00900 is thrown is that the single quotes become incorrectly read and so the results lose validity. 

A user on this forum also encountered ORA-00900:

Question:

I am trying to execute a procedure using parameter, if there are two parameters, I do not receive ORA-00900, but for other parameter, this message is thrown:

ORA-00900: invalid SQL statement

When I try this, my procedure attempts to update.  This update is successful with the backend and three rows, however, it does not update the entire table.  Her is the procedure:

select ,insert,update grant permission are given to the table.
update statement within procedure:

update table_customer set x_customer_value =
(select to_number(FLD2) from cfg_asciifiles
where to_number(FLD1)='100000195'
and process_flag is null
and inputfilename='c100'
and cno='test1.txt')
where x_customer_id in (select to_number(FLD1)
from cfg_asciifiles
where process_flag is null
and inputfilename='test1.txt'
and cno='c100');

Answer:

The ORA-00900 issues have to do with the parameters passing through the procedure because there are text strings being used.  You should use a dynamic SQL in your stored procedure:

cmmd:='ALTER SESSION SET CURSOR_SHARING=SIMILAR';
username:=SYS_CONTEXT('USERENV','SESSION_USER');
IF username LIKE 'APPL%' then
EXECUTE IMMEDIATE cmmd;
EXECUTE IMMEDIATE cmmd2;
END IF;

For more information on this try:

Oracle Dynamic PL/SQL Stored Procedures

Late Binding and Runtime Binding in PL/SQL