I am tasked to export users from an old project to another database, however the table name is USER (I was not around when that choice was made.)
In databases like MySQL, I could do
SELECT * FROM `user`;
But that escape character is illegal in Oracle.
So, how can I write the above query in Oracle?
Use double-quotes, not backticks, as referenced in the documentation.
SELECT * FROM "user";
Depending on how it was created - and how it appears in the data dictionary, which you can check with select table_name from user_tables where lower(table_name) = 'user' (with single quotes because here it's a string literal not an identifier!) - you may need it to be mixed-case or uppercase:
SELECT * FROM "USER";
As that documentation says, unquoted names are not case-sensitive; but quoted names are. One of several reasons to avoid them if you can.
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how to convert csv to table in oracle
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Closed 4 years ago.
We’ve got a page that displays a list of records, and the user is allowed to check the desired lines, and then get a report printed of those selected records. I’m trying to define the Oracle Report to have a single parameter which would be a comma-delimited list of the IDs to be printed. However it is not working. The SQL is something like this:
Select * from CEP_TABLE where Table_ID in (:P_IDLIST)
If I define the parameter to be numeric, I get an “invalid parameter input” error when trying to give it 654,655 – it doesn’t like having the comma.
If I define the parameter to be character, it accepts the parameter but then the database gives an “invalid number” error. It appears it is substituting the bind variable with the entire parameter in quotes – e.g.
Select * from CEP_TABLE where Table_ID in (‘654,655’)
But I want it without the quotes:
Select * from CEP_TABLE where Table_ID in (654,655)
I can get the report to work if I define multiple parameters – e.g. Table_ID in (:P1,:P2,:P3,:P4) but they could have a hundred items they want to include so it seems crazy to define 100 parameters – and really… I don’t want any limit.
Has anyone tackled this problem before? – it seems like it would be pretty common. I could have the page write out the selected ids to some temporary table and then define the query to join to that table, but that also seems excessive.
There's a hero that comes to rescue, and his name is lexical parameter.
You said that your query looks like this:
select *
from CEP_TABLE
where Table_ID in (:P_IDLIST)
Report already contains parameter named p_idlist. Now create another one, manually; let's call it lex_idlist. Its datatype should be character, its length somewhat larger than p_idlist parameter's (for example, if p_idlist is character(50), make lex_idlist character(70)).
Then rewrite query as follows:
select *
from cep_table
&lex_idlist
Go to After Parameter Form trigger which should look like this:
function AfterPForm return boolean is
begin
:lex_idlist := 'where table_id in (' || :p_idlist || ')';
return (TRUE);
end;
That's all - compile the report and run it. Enter some values into p_idlist parameter (such as 654,655). The trigger will dynamically create the WHERE clause, store it into the lexical parameter which will then "act" as if it was a real WHERE clause.
Read more about lexical parameters in online Reports Help system.
This is a very common and non-trivial question.
You need to split a single input string into its component tokens. Since I don't have your table, I illustrate how it's done on the emp table in the standard scott schema; here is how you can get the rows for the list of department numbers given in a single comma-separated string, such as '10,30':
select * from scott.emp
where deptno in
(select to_number(regexp_substr(:p_deptno, '\d+', 1, level)) from dual
connect by level <= regexp_count(:p_deptno, '\d+')
)
;
In fairness, there are also methods that don't split the string, and instead play silly games with string comparisons; but those will be quite ineffective - for example they would not allow you to use an index you may have on table_id (or on deptno in my example).
I use
SELECT * FROM ALL_OBJECTS WHERE OBJECT_TYPE IN ('FUNCTION','PROCEDURE','PACKAGE')
to get list of object but I see in oject_name column only name with uppercase letter like 'CHECKDOCNO' when I want to get CheckDocNo
As per https://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements008.htm#i27570 non quoted names are always case insensitive and are stored as uppercase.
Use quoted identifiers instead.
One of my columns is called from. I can't change the name because I didn't make it.
Am I allowed to do something like SELECT from FROM TableName or is there a special syntax to avoid the SQL Server being confused?
Wrap the column name in brackets like so, from becomes [from].
select [from] from table;
It is also possible to use the following (useful when querying multiple tables):
select table.[from] from table;
If it had been in PostgreSQL, use double quotes around the name, like:
select "from" from "table";
Note: Internally PostgreSQL automatically converts all unquoted commands and parameters to lower case. That have the effect that commands and identifiers aren't case sensitive. sEleCt * from tAblE; is interpreted as select * from table;. However, parameters inside double quotes are used as is, and therefore ARE case sensitive: select * from "table"; and select * from "Table"; gets the result from two different tables.
These are the two ways to do it:
Use back quote as here:
SELECT `from` FROM TableName
You can mention with table name as:
SELECT TableName.from FROM TableName
While you are doing it - alias it as something else (or better yet, use a view or an SP and deprecate the old direct access method).
SELECT [from] AS TransferFrom -- Or something else more suitable
FROM TableName
Your question seems to be well answered here, but I just want to add one more comment to this subject.
Those designing the database should be well aware of the reserved keywords and avoid using them. If you discover someone using it, inform them about it (in a polite way). The keyword here is reserved word.
More information:
"Reserved keywords should not be used
as object names. Databases upgraded
from earlier versions of SQL Server
may contain identifiers that include
words not reserved in the earlier
version, but that are reserved words
for the current version of SQL Server.
You can refer to the object by using
delimited identifiers until the name
can be changed."
http://msdn.microsoft.com/en-us/library/ms176027.aspx
and
"If your database does contain names
that match reserved keywords, you must
use delimited identifiers when you
refer to those objects. For more
information, see Identifiers (DMX)."
http://msdn.microsoft.com/en-us/library/ms132178.aspx
In Apache Drill, use backquotes:
select `from` from table;
If you ARE using SQL Server, you can just simply wrap the square brackets around the column or table name.
select [select]
from [table]
I have also faced this issue.
And the solution for this is to put [Column_Name] like this in the query.
string query= "Select [Name],[Email] from Person";
So it will work perfectly well.
Hi I work on Teradata systems that is completely ANSI compliant. Use double quotes " " to name such columns.
E.g. type is a SQL reserved keyword, and when used within quotes, type is treated as a user specified name.
See below code example:
CREATE TABLE alpha1
AS
(
SEL
product1
type_of_product AS "type"
FROM beta1
) WITH DATA
PRIMARY INDEX (product1)
--type is a SQL reserved keyword
TYPE
--see? now to retrieve the column you would use:
SEL "type" FROM alpha1
I ran in the same issue when trying to update a column which name was a keyword. The solution above didn't help me. I solved it out by simply specifying the name of the table like this:
UPDATE `survey`
SET survey.values='yes,no'
WHERE (question='Did you agree?')
The following will work perfectly:
SELECT DISTINCT table.from AS a FROM table
Some solid answers—but the most-upvoted one is parochial, only dealing with SQL Server. In summary:
If you have source control, the best solution is to stick to the rules, and avoid using reserved words. This list has been around for ages, and covers most of the peculiarities. One tip is that reserved words are rarely plural—so you're usually safe using plural names. Exceptions are DIAGNOSTICS, SCHEMAS, OCTETS, OFFSETS, OPTIONS, VALUES, PARAMETERS, PRIVILEGES and also verb-like words that also appear plural: OVERLAPS, READS, RETURNS, TRANSFORMS.
Many of us don't have the luxury of changing the field names. There, you'll need to know the details of the RDBM you're accessing:
For SQL Server use [square_braces] around the name. This works in an ODBC connection too.
For MySQL use `back_ticks`.
Postgres, Oracle and several other RDBMs will apparently allow "double_quotes" to be used.
Dotting the offending word onto the table name may also work.
You can put your column name in bracket like:
Select [from] from < ur_tablename>
Or
Put in a temprary table then use as you like.
Example:
Declare #temp_table table(temp_from varchar(max))
Insert into #temp_table
Select * from your_tablename
Here I just assume that your_tablename contains only one column (i.e. from).
In MySQL, alternatively to using back quotes (`), you can use the UI to alter column names. Right click the table > Alter table > Edit the column name that contains sql keyword > Commit.
select [from] from <table>
As a note, the above does not work in MySQL
Judging from the answers here and my own experience. The only acceptable answer, if you're planning on being portable is don't use SQL keywords for table, column, or other names.
All these answers work in the various databases but apparently a lot don't support the ANSI solution.
Simple solution
Lets say the column name is from ; So the column name in query can be referred by table alias
Select * from user u where u.from="US"
In Oracle SQL Developer, pl/sql you can do this with double quotes but if you use double quotes you must type the column names in upper case. For example, SELECT "FROM" FROM MY_TABLE
In my Oracle DB setup all the tables are created under dedicated user account SYS0MYUSER. When executing following query on my system I got SQL Error: ORA-00903: invalid table name
SELECT COUNT(*) FROM SYS0MYUSER.USER;
I tried to escape the reserved keyword like this:
SELECT COUNT(*) FROM "SYS0MYUSER.USER";
But then I got another error SQL Error: ORA-00942: table or view does not exist
What is the correct way to escape user name + reserved keyword combination ?
UPDATE:
What's about table alias do I have to use double quotes too ?
If you have created the table using quoted identifier, then you must always use double-quotation marks wherever you refer the object.
From documentation,
Database Object Naming Rules
Every database object has a name. In a SQL statement, you represent
the name of an object with a quoted identifier or a nonquoted
identifier.
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.
A nonquoted identifier is not surrounded by any punctuation.
For example,
SQL> CREATE TABLE "USER"(A NUMBER);
Table created.
SQL>
SQL> SELECT COUNT(*) FROM LALIT.USER;
SELECT COUNT(*) FROM LALIT.USER
*
ERROR at line 1:
ORA-00903: invalid table name
SQL>
SQL> SELECT COUNT(*) FROM LALIT."USER";
COUNT(*)
----------
0
SQL>
So, you need to refer the table as a quoted identifier:
SELECT COUNT(*) FROM SYS0MYUSER."USER";
Update OP updated his question regarding table alias.
What's about table alias do I have to use double quotes too ?
Table alias has nothing to do with the quoted identifier.
For example,
SQL> SELECT t.* FROM LALIT."USER" t;
no rows selected
SQL>
SELECT COUNT(*) FROM "SYS0MYUSER"."USER";