How do you reference a column in a table that has been concatenated? I am trying to reference the 'UniqueID' column in a join, but all the ways that I have tried it throw the ORA-00904 error saying "T2.UNIQUE ID:Invalid identifier".
create table cdm_user.uniquesubjectIDDEW as (
select distinct concat (site,screening_no) "UniqueID" , visit, site, Screening_no
from databrowser.v_data_entry_workflow
where study = '3508'
);
commit;
Select *
from cdm_user.uniquesubjectIDDEW t1
left join cdm_user.uniquesubjectIDDEW t2
on t1.UniqueID = t2.UniqueID
and t2.visit = 'Screening'
Where t1.visit = 'Week_52'
and t2.visit is null
Any help is much appreciated as I am new to SQL.
Unless quoted, identifiers such as table and columns names will be mapped to upper case. So your select will be interpreted as needing a column name UNIQUEID but you created the column name as "UniqueId" with quotes so it doesn't match.
You'll need to either unquote the name when you create the table or quote it in all queries.
Generally it is better not to use quoted, case-sensitive column names, which is why a lot of databases use underscores in table/column names as word separators rather than some variant of camel case.
Use quoted column name in createing command:
alter table cdm_user.uniquesubjectIDDEW add primary key ("UniqueID");
Related
i have a table whose name is like. But whenever i have to select data from like, i was getting this error, i figured it out public.like..but when i try to join two tables
SELECT *
FROM frame
INNER JOIN public.like
ON like.takerId = frame.likeId;
i get this error
ERROR: syntax error at or near "."
LINE 4: ON like.takerId = frame.likeId;
i also use public prefix but it throws
ERROR: column like.takerid does not exist
LINE 4: ON public.like.takerId = frame.likeId;
^
HINT: Perhaps you meant to reference the column "like.takerId".
even if it is saying column like.takerid does not exist , then why it gives me HINT: Perhaps you meant to reference the column "like.takerId". I dont know, i think it is problem with like table name, like is a sql syntax, and it assumes like and a sql syntax and throwing me error. Should I change my table name? Or is there any way to make sql case sensetive or how can i tell sql to ignore like. public.like is not working for joining table.
As like is a reserved keyword, you need to use double quotes for each occurance of it (unless it's prefixed with the schema name as you found out)
SELECT *
FROM frame
JOIN public.like ON "like".takerId = frame.likeId;
Or
SELECT *
FROM frame
JOIN "like" ON "like".takerId = frame.likeId;
Or use an alias
SELECT *
FROM frame f
JOIN "like" l ON l.takerId = f.likeId;
But in the long run you should find a different name for the table that does not require quoting.
You should definitely chose another name for your table. LIKE is a reserved command, and it is considered a bad practice to use it, although possible by using ", e.g.
CREATE TABLE public."like" (id int);
INSERT INTO public."like" VALUES (42);
SELECT * FROM "public.like"
EDIT: As pointed out by #a_horse_with_no_name, specifying a schema in temporary tables won't work (check db<>fiddle), so only the table name should be between double quotes as corrected in the snippet above. For temporary tables just omit the schema:
CREATE TEMPORARY TABLE "like" (id int);
INSERT INTO "like" VALUES (42);
SELECT * FROM "like"
Demo: db<>fiddle
We have Oracle table having default keyword(i.e in as field name) field name.Now i am querying table but unable to extract specific field data.
select a.filename,a.in from table a
Following error appears "invalid field name.
Try using double quotes.
select a."IN" from table a
You can use default (oracle reserved) keywords as the name of the columns but yes it is not advisable to use it.
Anyway, If you want to use oracle reserved keywords then you must have to enclose them in the double-quotes.
Note that oracle is case insensitive in terms of its object names until and unless it is wrapped in the double-quotes. it means if you enclose any object name in double-quotes then you must have to use them anywhere in the entire DB as case sensitive manner.
So if your table definition is:
CREATE TABLE YOUR_TABLE ("IN" NUMBER);
Then you need to use "IN" wherever you want to refer the column but if your table definition is:
CREATE TABLE YOUR_TABLE ("in" NUMBER);
Then you need to use "in" wherever you want to refer the column. -- case sensitive names.
I hope it will clear all your doubts.
Cheers!!
I have a SQL statement which ends in:
where <table_name>.<column_name> = '<column_value>'
I get the following error:
ORA-00904: "table_name"."column_name": invalid identifier
However, I know that the column is valid for sure. I also tried:
where <schema><table_name>.<column_name> = '<column_value>'
but got the same error. Lastly I tried without the identifiers:
where <column_name> = '<column_value>'
but that results in an column is ambiguously defined error.
What am I missing here?
Whole Query:
SELECT r.<COLUMN_NAME_1>, r.<COLUMN_NAME_2>, etc, t_append.*
FROM (
SELECT <COLUMN_NAME_1>, r.<COLUMN_NAME_2>, etc..
FROM <TABLE_NAME> ) r
inner join <TABLE_NAME> t_append on
t_append.<COLUMN_NAME_1> = r.<COLUMN_NAME_1>
AND t_append.<COLUMN_NAME_2> = r.<COLUMN_NAME_2>
AND etc...
WHERE <TABLE_NAME>.<COLUMN_NAME_1> = '<COLUMN_VALUE1>'
AND <TABLE_NAME>.<COLUMN_NAME_2> = '<COLUMN_VALUE2>'
This query takes composite key columns and value and then returns the composite key values followed by the row data which the key represents.
Apart from the above mentioned suggesstions,there may two possibilities according to me. You may get
ORA-00904: "table_name"."column_name": invalid identifier
1) if you don't have necessary permissions on the accessing objects. (confirm your permission on the object)
2) if your column was defined with double quotes like below
create table test("CheckMyColumn" number));
then it will be case sensitive. (Refer the table definition and try with same case)
The reason of a column ambiguously is because oracle doesn't know which column you are referring , it seems in your query you have specify 2 tables( from tab1 , tab2 ).
As for "table_name"."column_name": invalid identifier it means for sure column_name column for table table name doesn't exists, can you provide the ddl of the table.
I have a db table say, persons in Postgres handed down by another team that has a column name say, "first_Name". Now am trying to use PG commander to query this table on this column-name.
select * from persons where first_Name="xyz";
And it just returns
ERROR: column "first_Name" does not exist
Not sure if I am doing something silly or is there a workaround to this problem that I am missing?
Identifiers (including column names) that are not double-quoted are folded to lowercase in PostgreSQL. Column names that were created with double-quotes and thereby retained uppercase letters (and/or other syntax violations) have to be double-quoted for the rest of their life:
"first_Name"
Values (string literals / constants) are enclosed in single quotes:
'xyz'
So, yes, PostgreSQL column names are case-sensitive (when double-quoted):
SELECT * FROM persons WHERE "first_Name" = 'xyz';
Read the manual on identifiers here.
My standing advice is to use legal, lower-case names exclusively so double-quoting is never required.
To quote the documentation:
Key words and unquoted identifiers are case insensitive. Therefore:
UPDATE MY_TABLE SET A = 5;
can equivalently be written as:
uPDaTE my_TabLE SeT a = 5;
You could also write it using quoted identifiers:
UPDATE "my_table" SET "a" = 5;
Quoting an identifier makes it case-sensitive, whereas unquoted names are always folded to lower case (unlike the SQL standard where unquoted names are folded to upper case). For example, the identifiers FOO, foo, and "foo" are considered the same by PostgreSQL, but "Foo" and "FOO" are different from these three and each other.
If you want to write portable applications you are advised to always quote a particular name or never quote it.
The column names which are mixed case or uppercase have to be double quoted in PostgresQL. So best convention will be to follow all small case with underscore.
if use JPA I recommend change to lowercase schema, table and column names, you can use next intructions for help you:
select
psat.schemaname,
psat.relname,
pa.attname,
psat.relid
from
pg_catalog.pg_stat_all_tables psat,
pg_catalog.pg_attribute pa
where
psat.relid = pa.attrelid
change schema name:
ALTER SCHEMA "XXXXX" RENAME TO xxxxx;
change table names:
ALTER TABLE xxxxx."AAAAA" RENAME TO aaaaa;
change column names:
ALTER TABLE xxxxx.aaaaa RENAME COLUMN "CCCCC" TO ccccc;
You can try this example for table and column naming in capital letters. (postgresql)
//Sql;
create table "Test"
(
"ID" integer,
"NAME" varchar(255)
)
//C#
string sqlCommand = $#"create table ""TestTable"" (
""ID"" integer GENERATED BY DEFAULT AS IDENTITY primary key,
""ExampleProperty"" boolean,
""ColumnName"" varchar(255))";
Is it possible to create a table with column name containing space? If so how can I create and use it?
It is possible, but it is not advisable. You need to enclose the column name in double quotes.
create table my_table ("MY COLUMN" number);
But note the warning in the documentation:
Note: Oracle does not recommend using quoted identifiers for database
object names. These quoted identifiers are accepted by SQL*Plus, but
they may not be valid when using other tools that manage database
objects.
The name will be case-sensitive, and you wil have to enclose the name in double quotes every time you reference it:
select "MY COLUMN" from my_table;
So... don't, would be my advice...
Yes, it's possible. You just have to be sure to quote the column name. For instance:
CREATE TABLE Fubar ("Foo Bar" INT);
INSERT INTO Fubar VALUES (1337);
SELECT "Foo Bar" FROM SpaceMonster
Even though it's possible, it doesn't make it a good idea. You'll probably save yourself from a lot of pain if just replace all you spaces with underscores.
it is possible by naming the column between two "
example: "My columN" , the column name becomes case sensitive which means.
SELECT "my column" from table; --NOT OK
SELECT "My columN" from table; --OK
You can (see the Oracle doc) if you quote these appropriately. However I suspect this is not a good idea, since you'll have to quote everything. Generally db naming standards / conventions (e.g. here or here) favour using underscores (which don't require quoting) over whitespace.
This is the columns rule defined for oracle
Columns (for tables)
All columns are in form {alias}_{colname}. For example prs_id,
prs_name, prs_adr_id, adr_street_name. This guarantees that column
names are unique in a schema, except denormalized columns from
another table, which are populated using triggers or application
logic.
All columns are in singular. If you think you need a column name in plural think twice whether it is the right design? Usually it
means you are including multiple values in the same column and that
should be avoided.
All tables have surrogate primary key column in form {alias}_id, which is the first column in the table. For example, prs_id, mat_id,
adr_id.
you can always have alias for column name bu using ""
Did you Google for this? I did - the 6th link was this, in which I find the following:
create table employee (
"First Name" varchar2(20),
"Last Name" varchar2(20),
Address varchar2(60),
Phone varchar2(15),
Salary number,
EmpID number,
DeptID number
);
... which works fine when I tried it in 10g.