One day, I accidently issued a CREATE statement on SQL prompt in Oracle 9i with all columns enclosing within double quotation marks as below.
CREATE TABLE emp("emp_id" VARCHAR2(6) primary key,
"emp_name" VARCHAR2(30) not null, "salary" NUMBER);
instead of issuing it as the one mentioned below without enclosing the column names within quotation marks as usual.
CREATE TABLE emp(emp_id VARCHAR2(6) primary key,
emp_name VARCHAR2(30) not null, salary NUMBER);
This simple query (first mentioned) worked just fine with no problem at all and the emp table was created successfully just then I have created three rows into this table with the following INSERT command.
INSERT INTO emp VALUES("E0001", "Henery", 50000);
INSERT INTO emp VALUES("E0002", "Alex", 65000);
INSERT INTO emp VALUES("E0003", "Peter", 70000);
Three rows created successfully into the emp table. I then executed a SELECT statement to verify whether they were created or not and found that they were indeed created.
SELECT * FROM emp;
but when I executed the SELECT statement like the one below
SELECT emp_id, emp_name, salary FROM emp;
I made sure that though, I had used the same column names as they were actually in the emp table, Oracle issued an error indicating that "Such columns don't exist."
From the SQL Language Reference:
"A quoted identifier begins and ends with double quotation marks (").
If you name a schema object using a quoted identifier, then you must
use the double quotation marks whenever you refer to that object."
Related
I am working with an application using asp.net core 2.2 and efcore database first approach with Oracle database. I am using Oracle.EntityFrameworkCore (2.19.60) nuget package, successfully mapped db model, but when I try to fetch data from DBContext , getting error
ORA-00904: "m"."Id": invalid identifier
Oracle Database version: Oracle Database 12c Standard Edition Release 12.2.0.1.0 - 64bit Production
code:
var fetched = await myDatabaseContext.MyTableVersions.ToListAsync();
LinQ is generating following query :
SELECT "m"."Id", "m"."MAJORVERSION" FROM "MyTableVersions" "m"
Since It's not a correct syntax for PL/Sql query so getting error ORA-00904: "m"."Id": invalid identifier.
Is there any way to fix this error? Thanks.
I have searched on the web and found
Bug 30352492 - EFCORE: ORA-00904: INVALID IDENTIFIER
but that issue is related to schema.
The query is perfectly valid (db<>fiddle here), assuming your table looks something like
CREATE TABLE "MyTableVersions"
("Id" NUMBER,
MAJORVERSION NUMBER)
However, I suspect your table looks like
CREATE TABLE "MyTableVersions"
(ID NUMBER,
MAJORVERSION NUMBER)
I don't know what the class looks like that you're trying to fetch into, but I suspect it has a field named Id. If you can change the name of that field to ID (in other words, so that its capitalization matches the capitalization of the related database column) you might find it works then.
Double quotes are something you should avoid in Oracle world.
Your query:
SELECT "m"."Id", "m"."MAJORVERSION" FROM "MyTableVersions" "m"
means that column name is exactly Id (capital I followed by d). Only if that's really so, you should use double quotes. Otherwise, simply remove them:
SELECT m.id, m.MAJORVERSION FROM MyTableVersions m
The same goes for the table name - if it was created using mixed case (and you can't do that without double quotes), you'll have to use double quotes and exactly same letter case always. Otherwise, don't use them.
Oracle is case-insensitive regarding object and column names and are UPPERCASE by default:
SQL> create table test (id number);
Table created.
SQL> desc test
Name Null? Type
----------------------------------------- -------- -----------------
ID NUMBER
SQL> select table_name, column_name
2 from user_tab_columns
3 where table_name = 'TEST';
TABLE_NAME COLUMN_NAME
------------------------------ ------------------------------
TEST ID
SQL> insert into test (id) values (1);
1 row created.
SQL>
But, if you use mixed case with double quotes, then use them always:
SQL> create table "teST" ("Id" number);
Table created.
SQL> insert into test (id) values (1);
insert into test (id) values (1)
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> insert into "test" (id) values (1);
insert into "test" (id) values (1)
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> insert into "teST" (id) values (1);
insert into "teST" (id) values (1)
*
ERROR at line 1:
ORA-00904: "ID": invalid identifier
SQL> insert into "teST" ("Id") values (1);
1 row created.
SQL>
So: first make sure what table and column names really are, then use them appropriately.
To avoid problems with case-sensitivity, add the option to eliminate EF to add quotes to the generated queries. For instance, if you are using Devart Oracle provider, this is done in the following way:
public override void ConfigureServices(ServiceConfigurationContext context)
{
Configure<AbpDbContextOptions>(options =>
{
var config = Devart.Data.Oracle.Entity.Configuration.OracleEntityProviderConfig.Instance;
config.Workarounds.DisableQuoting = true;
...
}
}
If you are using official provider - just inherit from DbCommandInterceptor (do quotes replacement with empty character in dbCommand in ...Executing methods), add this interceptor to DbContextOptionsBuilder instance.
I created a before delete trigger:
create or replace trigger myTrigger3
before delete on emp
for each row
begin
update emp set mgr = 'Null' where mgr = :old.emp_name;
end;
Where table is
emp(emp_id integer primary key, emp_name varchar(20), mgr varchar(20))
But when I run this statement the trigger is not running.
delete from emp where emp_id = 1004;
select * from emp;
Error report -
ORA-04091: table DB20178004.EMP is mutating, trigger/function may not see it
ORA-06512: at "DB20178004.MYTRIGGER3", line 2
ORA-04088: error during execution of trigger 'DB20178004.MYTRIGGER3'
You can prefer adding a foreign key constraint with set null option instead of such a trigger. Of course you need a primary key should already been defined on emp_id column :
alter table emp
add constraint fk_mgr foreign key(mgr)
references emp(emp_id)
on delete set null;
Whenever you delete the record with an emp_id which has matching values with mgr column those will be emptied after deletion of the record with that emp_id.
But please prefer a data type(numeric) for mgr conforming with the column
emp_id such as integer to be able to define a foreign key
constraint.
Demo
By the way,
I recommend you to use soft-deletion. e.g. adding a column active to the table and
set value of it to zero whenever want to delete, and do not show the
records with active=0 on the application.
If you insisting on deletion do not filter by emp_name column, since
there can be more than one people with the common name, but using emp_id
is better by far as being unique within the table.
In my main table having table structure column without double quotes but when in View column with double quotes. While inserting data from view into table then getting error.
Here is the table structure of tbl
create table tbl (ID number(10),
name varchar2(50),
addr varchar2(200));
While View is-
create or replace view t_view as
select "ID", "name", "addr" from tbl;
While inserting data into tbl from t_view -
insert into tbl
select * from t_view;
Then getting error ORA- 00904: "addr": Invalid identifier.
So how to resolve this issue, can i remove the double quotes from creation of view.
Remove all double quotes from everywhere in your code.
If you use them while creating objects, you'll have to use them always, specifying exactly same letter case.
Get rid of those, Oracle is - by default - case insensitive and treats all names as uppercase (but you can reference them any way you want, just don't use double quotes!).
Oracle stores the name of any object in UPPERCASE by default. If you have provided double quotes then only Oracle stores the name of the object as it is.
Double quotes - Case sensitive
No quotes - Case insensitive - Stores the name in UPPERCASE
In your case, While writing the DDL of the table, you have not provided the name of the column in double quotes so your table name and column names are stored in UPPERCASE in the metadata.
You can see the same using the following query
select table_name, column_name from user_tab_columns where table_name = 'TBL';
For giving your answer, create the view either of the following syntaxes:
create or replace view t_view as
select ID, name, addr from tbl; -- no double quotes
create or replace view t_view as
select "ID", "NAME", "ADDR" from tbl; -- UPPERCASE column names in double quotes
See the demo here
Cheers!!
What is it you are trying to accomplish. Your request just doesn't make sense. Your intended statement
insert into tbl select * from t_view;
accomplishes exactly the same thing as
insert into tbl select * from tbl;
It's not that you cann't do this (you can), but it can only cause massive duplicate data issues or (hopefully) unique constraint violations.
I have an insert statement that I am trying to run against an Oracle database. The insert statement is very simple, and I only want to insert a value into one column. The table itself has more than one column, but I am only interested in filling one of the columns with data. The format of my query is similar to the one below:
insert into myTable (col1) Values (val1)
However, this throws the following error:
ORA-00904: "col1": invalid identifier
I've checked to make sure that the column is named correctly, and my only other thought is that something is wrong with my syntax. There are no constraints on the table such as primary keys. Is it possible to only insert values into certain columns when executing an insert statement in Oracle?
Check that you didn't quote the column name on creation of the table. If you did, the column name is stored as you quoted it. For example:
create table table1 (
id number(2)
)
has a different column name to this
create table table2 (
"id" number(2)
)
Oracle by default stores the (unquoted) column names in uppercase. Quoted are stored as is.
You can use a DESC table_name to see how the columns are stored.
The following
select id from table1
select iD from table1
select ID from table1
fetch the records, while only
select "id" from table2
will fetch records.
select id from table2
will throw the ORA-00904 : "ID" : invalid identifier error.
You may have inadvertently done the quoting during creation while using tools as established below:
https://community.oracle.com/thread/2349926
Btw: Yes it is possible to insert records for only one column, as long as the other columns do not have a NOT NULL constraint on them.
Actually, I think you may be double quoting the column in the insert statement (not on table creation), although your example is misleading. I guess this because of your error, which says "col1" is invalid, not "COL1" is invalid. Consider this simple test:
SQL> create table mytable
(
col1 varchar2(10)
)
Table created.
SQL> -- incorrect column name, without double quotes
SQL> insert into mytable(col2) values ('abc')
insert into mytable(col2) values ('abc')
Error at line 9
ORA-00604: error occurred at recursive SQL level 1
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at line 11
ORA-00904: "COL2": invalid identifier
SQL> -- incorrect column name, with double quotes
SQL> insert into mytable("col2") values ('abc')
insert into mytable("col2") values ('abc')
Error at line 12
ORA-00604: error occurred at recursive SQL level 1
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at line 11
ORA-00904: "col2": invalid identifier
SQL> -- correct column name, without double quotes (works)
SQL> insert into mytable(col1) values ('abc')
1 row created.
SQL> -- correct column name, with double quotes (fails)
SQL> insert into mytable("col1") values ('abc')
insert into mytable("col1") values ('abc')
Error at line 18
ORA-00604: error occurred at recursive SQL level 1
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at line 11
ORA-00904: "col1": invalid identifier
The last failed insert attempt is what I think you may be doing:
insert into mytable("col1") values ...
based on the error message:
ORA-00904: "col1": invalid identifier
So the solution would simply be remove the double quoting around the column name in the insert.
It's most probably a syntax error
Desc myTable;
insert into myTable (col1) Values ('val1')
Ensure col1 is a valid column in the table, and you're simply not trying to say 'select the left-most column.
edit: Is it possible to only insert values into certain columns when executing an insert statement in Oracle?
Yes if you want to only insert into certain columns then simply specify it
e.g.
insert into myTable (col1, col2, col6) Values ('val1', 'val2', 'val3');
This will only work if the column itself doesn't have a NOT NULL constraint - in which case it will not allow a value to be enetered (unless again there's a default value).
This is my query,
CREATE VIEW employee_vu AS(
SELECT employee_id,last_name "employee",department_id
FROM employees);
I am giving alias of columns in lower case ,and in it is stored in lower case
after doing desc i have confirmed.
But when i am trying to select this column employee :error occurs
EMPLOYEE: invalid identifier
Since all column name is stored in upper case ,is this the problem,Please explain what is the concept behind!
You would need to select it using double quotes and matching case:
select employee_id, "employee", department_id from employees;
That's why creating columns with double quoted identifiers is considered bad practice in Oracle.