What is the best practice for defining variables in sql? I've seen some of the other posts here and other places, but nothing I've tried as of yet has worked.
I'm using the below syntax, but the horse doesn't like the hay.
declare #variablename number(10)
set #variablename = (select COLUMN_NAME from TABLE_NAME where ANOTHER_COLUMN_NAME='something')
select MORE_COLUMN_NAMES from "NAME" where ANOTHER_NAME=#variablename;
This gives me some errors starting at "declare."
Error report -
ORA-06550: line 1, column 9:
PLS-00103: Encountered the symbol "#" when expecting one of the following:
begin function pragma procedure subtype type "an identifier"
"a double-quoted delimited-identifier" current cursor delete
exists prior
The symbol "#" was ignored.
I'm just starting out with very little database knowledge in so far as the application of things. I'm trying to become more versed in syntax and use.
Any help would be appreciated.
A PL/SQL block with variable declaration should be something like:
declare
var number;
var2 number;
begin
select count(1)
into var
from dual;
var2 := var * 2;
dbms_output.put_line('Var2 = ' || var2);
end;
In SQLPlus you can use bind variables:
variable var number
select count(1) into :var from dual;
select * from dual where rownum = :var;
or even substitution variables:
column var new_value valueFor_var
select count(1) as valueFor_var from dual;
select * from dual where rownum = &var;
Related
This should be easy as answers from here and here are suggesting. But, I am receiving an error:
ORA-00905: missing keyword
00905. 00000 - "missing keyword"
*Cause:
*Action: Error at Line: 7 Column: 36
My code:
vEXTERNAL_ACCOUNT_ID VARCHAR2(20);
(SELECT EXTERNAL_ACCOUNT_ID INTO vEXTERNAL_ACCOUNT_ID FROM TOF_ORDER_DATA WHERE ID =
(SELECT TOF_ORDER_DATA_ID FROM TOF_WFI WHERE WFI_ID = 3466444));
All I want is to set vEXTERNAL_ACCOUNT_ID from query above (it returns only one result). I don't understand what am I doing wrong here?
This is PL/SQL, so:
declare
vexternal_account_id varchar2(20);
begin
select external_account_id
into vexternal_account_id
from tof_order_data
where id = (select tof_order_data_id
from tof_wfi
where wfi_id = 3466444
);
dbms_output.put_line('Value = ' || vexternal_account_id);
end;
declare the variable
use begin-end keywords
remove outmost brackets
in order to display value returned by query, use dbms_output.put_line
don't forget to set serveroutput on in tool you use!
I am new to Oracle and learning; I am simply trying to run this T-SQL query
DECLARE #SearchObj varchar(100);
SET #SearchObj='%aldbrough%';
SELECT
obj_id,
name,
description
FROM
agnis.t_object
WHERE
lower(name) = ObjToSearch ;
I am using SQL Developer Oracle tool which also have a "Scratch Editor" to help with translation from T-SQL. When i run the tool it gave me this code
DECLARE
v_SearchObj VARCHAR2(100);
BEGIN
v_SearchObj := '%aldbrough%' ;
SELECT obj_id ,
NAME ,
DESCRIPTION
FROM agnis.t_object
WHERE LOWER(NAME) = ObjToSearch;
END;
but the same tool give me this error
Error report -
ORA-06550: line 10, column 26:
PL/SQL: ORA-00904: "OBJTOSEARCH": invalid identifier
ORA-06550: line 6, column 4:
PL/SQL: SQL Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
so what is the correct syntax to use a variable into a LIKE clause that returns multiple rows?
I hope I do not have to use cursors etc for such of a simple statement as suggested in this question
Well, yes - those "translators" don't always do what they are supposed to.
This is how your code should look like:
use like, not = in the where clause
in PL/SQL, you have to put the result of the select statement into something - for example, locally declared variables (as my example shows).
So:
DECLARE
v_SearchObj VARCHAR2 (100) := '%aldbrough%';
--
v_obj_id t_object.obj_id%TYPE;
v_name t_object.name%TYPE;
v_description t_object.description%TYPE;
BEGIN
SELECT obj_id, NAME, DESCRIPTION
INTO v_obj_id, v_name, v_description
FROM agnis.t_object
WHERE LOWER (NAME) LIKE v_searchobj;
END;
If such a code returns an error - too_many_rows (and yes, it does), then one option is to loop through rows and do something (such as display those values):
DECLARE
v_SearchObj VARCHAR2 (100) := '%aldbrough%';
BEGIN
FOR cur_r IN (SELECT obj_id, NAME, DESCRIPTION
FROM agnis.t_object
WHERE LOWER (NAME) LIKE v_searchobj)
LOOP
DBMS_OUTPUT.put_line (
'Name = ' || cur_r.name || ', description = ' || cur_r.description);
END LOOP;
END;
Since this is tagged SQL Developer, use a bind variable:
SELECT obj_id,
name,
description
FROM agnis.t_object
WHERE lower(name) = :ObjToSearch;
and SQL developer will pop up a dialog box where you can set the value of the ObjToSearch variable.
If you want to specify the bind variable in code then:
VARIABLE objtosearch VARCHAR2(50)
BEGIN
:objtosearch := '%aldbrough%';
END;
/
SELECT obj_id,
name,
description
FROM agnis.t_object
WHERE lower(name) = :ObjToSearch;
And run the statements as a script using F5 rather than as individual statements.
I have a Oracle related question. I would like to select a random sample out of a view or table in such a way that the SAMPLE clause is parameterized.
Given the following table.
CREATE TABLE FOO AS
(SELECT LEVEL AS ID
FROM DUAL
CONNECT BY LEVEL < 101
);
The following construct works, using a literal parameter in the SAMPLE clause.
SELECT ID FROM FOO SAMPLE (15); -- this will get a 15% sample
However,
DECLARE
N NUMBER := 50;
BEGIN
FOR r IN
( SELECT ID FROM FOO SAMPLE (N) -- <<< this won't work
)
LOOP
DBMS_OUTPUT.PUT_LINE( r.ID );
END LOOP;
END;
This block blows up when we put a parameter in the SAMPLE clause. It compiles and works if we put it a literal.
But if it is a variable, I get the following:
ORA-06550: line 5, column 33:
PL/SQL: ORA-00933: SQL command not properly ended
Any ideas? I'm racking by brains where the syntax gets broken.
The syntax does not allow a variable there.
One workaround would be to construct the SELECT statement dynamically. For example:
declare
l_rc sys_refcursor;
n number := 5;
begin
-- replace "mtl_system_items" with your table...
open l_rc FOR 'select count(*) from mtl_system_items sample (' || n || ')';
-- replace call to RETURN_RESULT with whatever processing you want
DBMS_SQL.RETURN_RESULT(l_rc);
end;
I am trying to declare a variable in workbench using an oracle db. I found two approaches which both don't seem to be recognized as workbench does not highlight either var nor define as command
define s = 'test'
SELECT &&s from dual
;
var s varchar(max)
exec: s := 'test'
SELECT &&s from dual
both throw an error 1064. You ahve an error in your sql syntax.
How can I declare a simple variable to do something like
x = 'test'
select * from t where y = x
You have two options.
When in PL/SQL, you have to declare it like this:
declare
l_s varchar2 := 'test';
begin
select l_s
into some_other_var
from dual
;
-- or
some_other_var := l_s;
end;
;
Or, when simply using in a query:
select :s
from dual
This will ask you for the value of s.
In the SQL Server, I can define local variables like this.
declare #id number := 1000
select * from tbl_A where id = #id;
select * from tbl_B where id = #id;
It is very convenient.
I tried to do same thing in PL/SQL but it doesn't work.
DECLARE id number;
select 1000 into id from dual;
Do you know how to do something similar? The simplest method is my objective.
If you want to define a local variable in PL/SQL, you need a complete PL/SQL block
DECLARE
id NUMBER;
BEGIN
SELECT 1000
INTO id
FROM dual;
END;
or just
DECLARE
id NUMBER := 1000;
BEGIN
<<do something that uses the local variable>>
END;
If you want to declare a variable in SQL*Plus
SQL> variable id number
SQL> begin
select 1000 into :id from dual;
end;
/
SQL> print id
ID
----------
1000
SQL> SELECT * FROM tbl_a WHERE id = :id
An alternative to DECLARE Block is to use a WITH Clause:
WITH my_params AS (
SELECT 123 AS min_id FROM DUAL
)
SELECT *
FROM some_table
WHERE id > (SELECT min_id FROM my_params)
It is more portable as many vendors support the WITH clause and you can change seamless from parameter to dynamic value. For example:
WITH my_params AS (
SELECT min(id) AS min_id FROM some_id_table
)
SELECT *
FROM some_table
WHERE id > (SELECT min_id FROM my_params)
Solution for Oracle SQL
DEF x = foo
SELECT '&x' FROM dual;
The result will be : foo
NB: The variable will keep the value even after execution. To clear variable run UNDEFINE x.
General syntax to declare variable in PL/SQL is
var_nm datatype [NOT NULL := var_value ];
var_nn is the name of the variable.
datatype is a valid PL/SQL datatype.
NOT NULL is an optional specification on the variable which this variable cannot be assigned null value.
var_value or DEFAULT value is also an optional specification, where you can initialize a variable with some specific value.
Each variable declaration is a separate statement and must be terminated by a semicolon.
We can assign value to variables in one of the following two ways -
direct assignment (Eg. var_nm:= var_value;)
Using select from (Eg. SELECT col_nm INTO var_nm FROM tbl_nm [WHERE clause];)
In you case as Justin Cave has already mentioned it can be
DECLARE
id number;
BEGIN
SELECT 1000 into id from dual;
dbms_output.put_line('id : '|| id );
END;
/
OR
DECLARE
id number := 1000;
BEGIN
dbms_output.put_line('id : '|| id );
END;
/
NOTE: '/' i.e Back slash after END keyword indicates to execute the above PL/SQL Block.
(Just stumbled across this thread.) Beginning with SQL*Plus 12.2, you can declare and assign a value at the same time:
SQL> var id number = 1000
SQL> select * from tbl_A where id = :id;
Oracle calls it input binding.
If you must do it in PL/SQL, the answer was given by others.