I have an SQL statement in Oracle SQL developer that has some variables:
DEFINE custom_date = "'22-JUL-2016'" --run1
DEFINE custom_date = "'25-JUL-2016'" --run2
SELECT * FROM TABLE WHERE date=&custom_date
The real query is much more complicated and has many more variables and new tables are created from the results of the query. How can I create a script so that the query is executed twice, the first time with the custom date set as in the first line and the second time as in the second line.
In Oracle, the &variable is a "substitution variable" and is not part of SQL; it is part of the SQL*Plus scripting language (understood by SQL Developer, Toad etc.)
The better option, and what you are asking about, is BIND VARIABLES. The notation is :variable (with a colon : instead of &), for example :custom_date.
The difference is that a substitution variable is replaced by its value in the front-end application (SQL Developer in your case) before the query is ever sent to the Oracle engine proper. A bind variable is substituted at runtime. This has several benefits; discussing them is outside the scope of your question.
When you execute a query with bind variables in SQL Developer, the program will open a window where you enter the desired values for the bind variables. You will have to experiment with that a little bit till you can make it work (for example I never remember if a date must be entered with the single quotes or without). Good luck!
Define is used in TRANSACT SQL. To do this Oracle way, You can create anonymus PL/SQL block, similar to this:
DECLARE
p_param1 DATE;
p_param2 NUMBER;
CURSOR c_cur1(cp_param1 DATE,cp_param2 NUMBER)
IS
SELECT * FROM table WHERE date = cp_param1
;
BEGIN
-- Execute it first time
p_param1 := TO_DATE('2016-09-01','YYYY-MM-DD');
FOR r IN c_cur1(p_param1)
LOOP
NULL;
END LOOP;
-- Execute it second time
p_param1 := TO_DATE('2015-10-11','YYYY-MM-DD');
FOR r IN c_cur1(p_param1)
LOOP
NULL;
END LOOP;
END;
And in it, You create cursor with parameters and execute it twice with different parameter.
I do not know why You want to execute this query twice, so the script abowe does nothing with results, but it certainly should execute Your query twice, with different params.
Related
Whenever I try to call a stored procedure in PostgreSQL that goes beyond inserting data, it takes forever to run, and it isn't that the query is complicated or the dataset is huge. The dataset is small. I cannot return a table from a stored procedure and I cannot even return 1 row or 1 data point from a stored procedure. It says it is executing the query for a very long time until I finally stop the query from running. It does not give me a reason. I can't let it run for hours. Any ideas on what might be happening? I have included stored procedures that I have tried to call.
Non-working example #1:
CREATE PROCEDURE max_duration(OUT maxD INTERVAL)
LANGUAGE plpgsql AS $$
DECLARE maxD INTERVAL;
BEGIN
SELECT max(public.bikeshare3.duration)
INTO maxD
FROM public.bikeshare3;
END;
$$ ;
CALL max_duration(NULL);
Non-working example #2:
CREATE PROCEDURE getDataByRideId2(rideId varchar(16))
LANGUAGE SQL
AS $$
SELECT rideable_type FROM bikeshare3
WHERE ride_id = rideId
$$;
CALL getDataByRideId2('x78900');
Working example
The only one that worked when called is an insert procedure:
CREATE OR REPLACE PROCEDURE genre_insert_data(GenreId integer, Name_b character varying)
LANGUAGE SQL
AS $$
INSERT INTO public.bikeshare3 VALUES (GenreId, Name_b)
$$;
CALL genre_insert_data(1, 'testName');
FUNCTION or PROCEDURE?
The term "stored procedure" has been a widespread misnomer for the longest time. That got more confusing since Postgres 11 added CREATE PROCEDURE.
You can create a FUNCTION or a PROCEDURE in Postgres. Typically, you want a FUNCTION. A PROCEDURE mostly only makes sense when you need to COMMIT in the body. See:
How to return a value from a stored procedure (not function)?
Nothing in your question indicates the need for a PROCEDURE. You probably want a FUNCTION.
Question asked
Adrian already pointed out most of what's wrong in his comment.
Your first example could work like this:
CREATE OR REPLACE PROCEDURE max_duration(INOUT _max_d interval = NULL)
LANGUAGE plpgsql AS
$proc$
BEGIN
SELECT max(b.duration) INTO _max_d
FROM public.bikeshare3 b;
END
$proc$;
CALL max_duration();
Most importantly, your OUT parameter is visible inside the procedure body. Declaring another instance as variable hides the parameter. You could access the parameter by qualifying with the function name, max_duration.maxD in your original. But that's a measure of last resort. Rather don't introduce duplicate variable names to begin with.
I also did away with error-prone mixed-case identifiers in my answer. See:
Are PostgreSQL column names case-sensitive?
I made the parameter INOUT max_d interval = NULL. By adding a default value, we don't have to pass a value in the call (that's not used anyway). But it must be INOUT instead of OUT for this.
Also, OUT parameters only work for a PROCEDURE since Postgres 14. The release notes:
Stored procedures can now return data via OUT parameters.
While using an OUT parameter, this advise from the manual applies:
Arguments must be supplied for all procedure parameters that lack
defaults, including OUT parameters. However, arguments matching OUT
parameters are not evaluated, so it's customary to just write NULL
for them. (Writing something else for an OUT parameter might cause
compatibility problems with future PostgreSQL versions.)
Your second example could work like this:
CREATE OR REPLACE PROCEDURE get_data_by_ride_id2(IN _ride_id text
, INOUT _rideable_type text = NULL) -- return type?
LANGUAGE sql AS
$proc$
SELECT b.rideable_type
FROM public.bikeshare3 b
WHERE b.ride_id = _ride_id;
$proc$;
CALL get_data_by_ride_id2('x78900');
If the query returns multiple rows, only the first one is returned and the rest is discarded. Don't go there. This only makes sense while ride_id is UNIQUE. Even then, a FUNCTION still seems more suitable ...
I'm writing a pretty basic stored procedure that just takes values from the sample DB2 database and computes the standard deviation. I wrote the procedure itself just fine, and I can call it without error. But I can't figure out how to actually display my result or select it in a statement. Everything I try results in a syntax error and I haven't been able to find anyone doing this specific task in my google searches.
This is the gist of my code (snipped for brevity):
CREATE PROCEDURE SAL_STD_DEV
(OUT std_dev real)
LANGUAGE SQL
BEGIN
--do stuff
SET std_dev = 10; --changed for simplicity
END#
CALL SAL_STD_DEV(?)#
All this runs, but just CALL doesn't create any output. What's the syntax to SELECT the out variable? I can't put a DECLARE before the CALL because it's not in a stored procedure, and PRINT doesn't work either.
(# is my terminal character because I'm using ; in the stored procedure)
Edit: Both the create procedure and call statements are made in the same SQL file, the database is connect to through localhost and I'm using DB2 11.1.0.1527 and developing in IBM Data Studio 4.1.2.
From wherever the CALL is being made, that feature might present a Result Set, despite apparently not presenting the result of an OUT parameter. If so, then the stored procedure perhaps could be revised to return the OUT value [instead, or additionally] as a result set, so that the interface that accepts the CALL statement as input, might present that result-set. Regardless:
In a statement processor [e.g. that is not a GUI, but] for which SELECT query output is presented, the following scripted requests should likely suffice:
create variable my_real real
;
call SAL_STD_DEV(my_real)
;
select my_real from sysibm.sysdummy1
;
I used to do Oracle development many many years ago. I have spent most of the past 15 years doing mainly SQL Server, and where I have done Oracle work, been insulated from the workings by Web services etc.
My question seems to have been asked on the web a few times, but it seems difficult somehow to communicate - at least judging by the answers. I very much appreciate that tools and functionality differ, know I have to learn new things, but this is so simple, yet seems so hard to do.
I am looking to do some ad-hoc queries on the database. At the moment we are using SQL Navigator - I am open to using other tools...
In SQL Server Management Studio, if you open a query window, type a bit of SQL that retuns a value or a set, you get a nice display of the rows or values in a results window.
I've gathered that with Oracle PL/SQL things are a bit different, worked out that I need to return a cursor - but how do I get a tool to display the results?
I started simple:
declare
my_id number := 356655;
cursor c1 is select my_id from dual;
begin
open c1;
end;
This runs fine - but how do I see the results? Are there any tools that deal with this as 'nicely' as SSMS? I am used to being able to do a lot of this, including stuff like
(perhaps not exactly the right syntax? but you get the idea...)
declare
my_id number := 356655;
cursor c1 is select name from my_table where id = my_id;
begin
open c1;
And having the results displayed to me as text/grid. Ideally that there is a nice solution. Some spiffy new tool, maybe?
With SQL Developer or SQL*Plus you can use a bind variable declared before the PL/SQL block:
variable rc refcursor;
declare
my_id number := 356655;
begin
open :rc for select my_id from dual;
end;
/
print rc
RC
-------------------------------
356655
You can also use a bind variable within the query, which can be useful:
variable my_id number;
variable rc refcursor;
execute :my_id := 356655;
begin
open :rc for select :my_id from dual;
end;
/
print rc
The variable and print commands are covered in the SQL*Plus documentation, which largely applies to SQL Developer as well - that has its own documentation, including the commands that are carried over from SQL*Plus.
If you have a function that returns a ref cursor then you can call that in a query, as select func(val) from dual, and then the results can go in a grid; or you can call the function (or procedure) with the same :rc bind variable and print it. But I'm not sure either is helpful if you are only doing ad hoc queries.
On the other hand, using a PL/SQL block for an ad hoc query seems a little heavy-handed, even if your queries are complicated. You'd need a good reason to open a cursor for a select statement from within a block, rather than just running the select directly. (Not sure if that's a SQL Server thing or if you actually have a real need to do this!). If you're just running a query inside the block, you don't need the block, even if you want to keep a bind variable for the values you're using in the query:
variable my_id number;
execute :my_id := 356655;
select :my_id from dual;
:MY_ID
----------
356655
I use Oracle SQL Developer.
Anyway, this should work in any oracle sql client:
If you just want to see your results, you can use
dbms_output.put_line('Foo' || somevar || ' bar');
Before this, run
SET SERVEROUTPUT ON
Check the examples at docs.oracle.com
I would suggest using sql developer available free from the oracle website. There is a button which allows you to run sql as a script which will get back what you want. SSMS doesn't work with pl/sql.
I am trying to convert a big list of SQL statements into a PostgreSQL stored procedure that uses a variable, one that should be populated from the result of one SELECT.
If you want to see what has to be run, you can check it here
As far as I know PostgreSQL does not allow use to use variables inside stored procedures that are using SQL language, so I'm looking for solutions that would require a minimal number of changes.
It's much easier after you find the right syntax:
Here is the procedure definition for plpgsql language:
DECLARE myvar integer;
BEGIN
SELECT INTO myvar FROM ...;
-- use myvar
END;
The code seems to be pretty repetitive. Will EXECUTE be of any help? (manual about execute) (example and more information) It allows you to run predefined queries and create new ones on the fly.
I'm trying to run multiple ddl statements within one Execute Immediate statement.
i thought this would be pretty straight forward but it seems i'm mistaken.
The idea is this:
declare v_cnt number;
begin
select count(*) into v_cnt from all_tables where table_name='TABLE1' and owner = 'AMS';
if v_cnt = 0 then
execute immediate 'CREATE TABLE TABLE1(VALUE VARCHAR2(50) NOT NULL) ALTER TABLE TABLE1 ADD (MYVAL2 NVARCHAR2(10))';
end if;
end;
however this results in an error
ORA-00911: invalid character
ORA-06512: at line 10
Each of the statements within the batch run fine if i execute them by themselves. and if i take this statement and execute it, it will run fine (with the ; between the 2 statements). If i remove the ; between statements i get a different error about invalid option
the plan is that i'll be able to build a table, export the table schema for this table including all it's alter statements, and then run the batch against another system as part of an install/update process.
So, how do i batch these DDL statements within a single execute immediate? Or is there a better way to do what i'm needing?
I'm a bit of a Oracle newb, i must admit. Thank you all for your patience.
The semicolon is not part of Oracle's SQL syntax. SQL*Plus and other client side tools use semicolon to signal the end of a SQL Statement, but the server doesn't see it.
We can force SQL*Plus to pass the semicolon to the DB:
SQL> set sqlterminator off
SQL> select * from user_tables;
2 /
select * from user_tables;
*
ERROR at line 1:
ORA-00911: invalid character
If i take this statement and execute it, it will run fine (with the ; between the 2 statements) The client tool you are using, breaks it into two calls to the DB.
So, I don't think it is possible to pass multiple statements inside an execute immediate.
I suppose one could call execute immediate with a string containing an anonymous PL/SQL block, with individual calls to execute immediate inside it ... and I don't know what the point of doing that would be. ;)
Why do you need a single EXECUTE IMMEDIATE call? Surely just do it as 2 calls?
Bear in mind that each DDL statement contains an implicit COMMIT, so there's no concurency benefit to doing it as a single call.
Also, why not just set up the table correctly in the first call? You could do...
CREATE TABLE TABLE1(VALUE VARCHAR2(50) NOT NULL, MYVAL2 NVARCHAR2(10))
...instead of needing 2 calls.
Also, have you looked at DBMS_METADATA... it can generate DDL for objects such as tables for you.