I'm given quite a huge table My_Table and a user-defined collection Picture_Arr as an input usually having 5-10 rows declared as:
TYPE Picture_Rec IS RECORD (
seq_no NUMBER,
task_seq NUMBER);
TYPE Picture_Arr IS TABLE OF Picture_Rec;
In MS SQL I would normally write something like:
DECLARE #Picture_Arr TABLE (seq_no INT, task_seq INT)
SELECT M.*
FROM My_Table M
INNER JOIN #Picture_Arr A
ON M.seq_no = A.seq_no AND M.task_seq = A.task_seq
But I can't get my head around how to re-write the same code in Oracle as Picture_Arr is not a table. As some tutorials state that I could've looped through My_Table and compare keys, but is it efficient in Oracle or is there another way of doing that?
Perhaps this is what you are looking for. It is a bit complicated to understand what is the desired output, and whether the data of the record is stored somewhere or not
create type Picture_Rec as object(
seq_no NUMBER,
task_seq NUMBER);
)
/
create type Picture_Tab as table of Picture_Rec
/
create or replace function get_picture_list
return Picture_Tab
is
l_pic Picture_Tab;
begin
select Picture_Rec ( seqno, taskseq )
bulk collect into l_pic
from your_table; -- the table you have these records
return l_pic;
end;
/
Then you run
SELECT M.*
FROM My_Table M
JOIN TABLE ( get_picture_list() ) p
ON M.seq_no = p.seq_no AND M.task_seq = p.task_seq
Related
Is there a way to write sql for Oracle, MS SQL:
Select * from table where id in(:arr)
Select * from table where id in(#arr)
With one param in sql 'arr' to represent an array of items?
I found examples that explode arr to #arr0,.., #arrn and feed array as n+1 separate parameters, not array, like this
Select * from table where id in(:arr0, :arr1, :arr2)
Select * from table where id in(#arr0, #arr1, #arr2)
Not what i want.
These will cause change in sql query and this creates new execution plans based on number of parameter.
I ask for .net, c# and Oracle and MS SQL.
Thanks for constructive ideas!
/ip/
I believe Table Value Parameter is good option for this case. Have a look at a sample code below in SQL Server.
-- Your table
CREATE TABLE SampleTable
(
ID INT
)
INSERT INTO SampleTable VALUES
(1010),
(2010),
(3010),
(4010),
(5010),
(6010),
(7010),
(8030)
GO
-- Create a TABLE type in SQL database which you can fill from front-end code
CREATE TYPE ParameterTableType AS TABLE
(
ParameterID INT
--, some other columns
)
GO
-- Create a stored proc using table type defined above
CREATE PROCEDURE ParameterArrayProcedure
(
#ParameterTable AS ParameterTableType READONLY
)
AS
BEGIN
SELECT
S.*
FROM SampleTable S
INNER JOIN #ParameterTable P ON S.ID = P.ParameterID
END
GO
-- Populated table type variable
DECLARE #ParameterTable AS ParameterTableType
INSERT INTO #ParameterTable (ParameterID) VALUES (1010), (4010), (7010)
EXECUTE ParameterArrayProcedure #ParameterTable
DROP PROCEDURE ParameterArrayProcedure
DROP TYPE ParameterTableType
DROP TABLE SampleTable
GO
Apart from Table Value Parameter, you can also use Json or XML values as SQL parameter but yes, it will definitely change your execution plan accordingly.
In addition to a Table Valued Parameter as Steve mentioned, there are a couple of other techniques available. For example you can parse a delimited string
Example
Declare #arr varchar(50) = '10,20,35'
Select A.*
From YourTable A
Join string_split(#arr,',') B on A.ID=value
Or even
Select A.*
From YourTable A
Where ID in ( select value from string_split(#arr,',') )
Oracle
In other languages (i.e. Java) you can pass an SQL collection as a bind parameter and directly use it in an SQL statement.
However, C# does not support passing SQL collections and only supports passing OracleCollectionType.PLSQLAssociativeArray (documentation link) which is a PL/SQL only data-type and cannot be used (directly) in SQL statements.
To pass an array, you would need to pass a PLSQLAssociativeArray to a PLSQL stored procedure and use that to convert it to an SQL collection that you can use in an SQL statement. An example of a procedure to convert from a PL/SQL associative array to an SQL collection is:
CREATE TYPE IntList AS TABLE OF INTEGER
/
CREATE PACKAGE tools IS
TYPE IntMap IS TABLE OF INTEGER INDEX BY BINARY_INTEGER;
FUNCTION IntMapToList(
i_map IntMap
) RETURN IntList;
END;
/
CREATE PACKAGE BODY tools IS
FUNCTION IntMapToList(
i_map IntMap
) RETURN IntList
IS
o_list IntList := IntList();
i BINARY_INTEGER;
BEGIN
IF i_map IS NOT NULL THEN
i := o_list.FIRST;
WHILE i IS NOT NULL LOOP
o_list.EXTEND;
o_list( o_list.COUNT ) := i_map( i );
i := i_map.NEXT( i );
END LOOP;
END IF;
RETURN o_list;
END;
END;
/
I'm new to working with PL/pgSQL, and I'm attempting to create a function that will either find the ID of an existing row, or will insert a new row if it is not found, and return the new ID.
The query contained in the function below works fine on its own, and the function gets created fine. However, when I try to run it, I get an error stating "ERROR: column reference "id" is ambiguous". Can anybody identify my problem, or suggest a more appropriate way to do this?
create or replace function sp_get_insert_company(
in company_name varchar(100)
)
returns table (id int)
as $$
begin
with s as (
select
id
from
companies
where name = company_name
),
i as (
insert into companies (name)
select company_name
where not exists (select 1 from s)
returning id
)
select id
from i
union all
select id
from s;
end;
$$ language plpgsql;
This is how I call the function:
select sp_get_insert_company('TEST')
And this is the error that I get:
SQL Error [42702]: ERROR: column reference "id" is ambiguous
Detail: It could refer to either a PL/pgSQL variable or a table column.
Where: PL/pgSQL function sp_get_insert_company(character varying) line 3 at SQL statement
As the messages says, id is in there twice. Once in the queries, once in the table definition of the return type. Somehow this clashes.
Try qualifying the column expressions, everywhere.
...
with s as (
select
companies.id
from
companies
where name = company_name
),
i as (
insert into companies (name)
select company_name
where not exists (select 1 from s)
returning companies.id
)
select i.id
from i
union all
select s.id
from s;
...
By qualifying the column expression the DBMS does no longer confuse id of a table with the id in the return type definition.
The next problem will be, that your SELECT has no target. It will tell you to do a PERFORM instead. But I assume you want to return the results. Change the body to
...
RETURN QUERY (
with s as (
select
companies.id
from
companies
where name = company_name
),
i as (
insert into companies (name)
select company_name
where not exists (select 1 from s)
returning companies.id
)
select i.id
from i
union all
select s.id
from s);
...
to do so.
In the function you display there is no need for returns table (id int). It's supposed to always return exactly one integer ID. Simplify to RETURNS int. This also makes ERROR: column reference "id" is ambiguous go away, since we implicitly removed the OUT parameter id (visible in the whole function block).
How to return result of a SELECT inside a function in PostgreSQL?
There is also no need for LANGUAGE plpgsql. Could simply be LANGUAGE sql, then you wouldn't need to add RETURNS QUERY, either. So:
CREATE OR REPLACE FUNCTION sp_get_insert_company(_company_name text)
RETURNS int AS
$func$
WITH s as (
select c.id -- still good style to table-qualify all columns
from companies c
where c.name = _company_name
),
i as (
insert into companies (name)
select _company_name
where not exists (select 1 from s)
returning id
)
select s.id from s
union all
select i.id from i
LIMIT 1; -- to optimize performance
$func$ LANGUAGE sql;
Except that it still suffers from concurrency issues. Find a proper solution for your undisclosed version of Postgres in this closely related answer:
Is SELECT or INSERT in a function prone to race conditions?
I have a main table that has two columns with table names and id's. And I have those tables with table names in my DB.
For example, I find particular table name, selecting id. And then I want to populate table with that name with data. And I want to do that in one query. How I can do that?
The goal: to populate with data all tables at once, that has the names that similar with values in table name column from main table.
That is how I'm getting the list of tables. I should probably loop through it.
select tbl from asp_tbl where asp in (
select id from (
SELECT * FROM DIMENSION WHERE EXTERNALKEY LIKE 'W16%')
);
And then I will try to merge the data from other tables inside the table that needs to be populated:
MERGE INTO tbl d
USING
(SELECT ? nums, ? names from data_table) s
ON(d.product = s.product and d.ga = s.ga and d.metric_id = s.metric_id)
WHEN MATCHED THEN UPDATE SET d.names = s.names
WHEN NOT MATCHED THEN INSERT (nums, names)values(s.nums,s.names);
Did I provide enough info?
As I understand you need some stored procedure witch may fulfil a table with some test data. If so you may write something like:
create procedure fulfil_test_data (p_table_name varchar2) is
begin
for x IN (select tbl from asp_tbl where asp in (
SELECT table_id FROM DIMENSION WHERE EXTERNALKEY LIKE p_table_name )) loop
execute immediate 'insert into '|| x.tbl ||' (nums, names)
select level , chr(ascci(''A'') + mod(level,26)) from dual connect by level < 1001';
end loop;
end;
/
And call it
begin
fulfil_test_data('W16%');
end;
/
colleagues
I have a problem with table function in Oracle.
More specifically, I have a function that converts BLOB into table of varchar2.
create type string_array is table of varchar2(255);
create or replace function blob_to_strings(p_blb in BLOB) return string_array as
begin
-- some processing here
end;
Also I have table containing BLOBS I need to work with.
create table my_blobs (id number, data blob)
Now, having id in my_blobs table, I want to query result of convert function. Something like
select t.* from table(blob_to_strings(b.data)) t, my_blobs b where b.id = 123;
(I know this is incorrect, just showing what I need)
This query expectedly returns b.data: invalid identifier as you can't access other table columns inside from section.
I understand how to do it in PL/SQL running 2 queries, but really need to do it in SQL.
Can anybody help me?
Thank you in advance.
UPD: I tried following:
select * from table(select blob_to_strings(b.data) from my_blobs b where b.id = 123);
Result: ORA-00902: invalid datatype
Any other ideas?
Possibly the issue with your original query was that you had the table name coming after the attempt to select from the array (from table(blob_to_strings(b.data)) t, my_blobs b). In other words, you were trying to select from something that hadn't yet been declared. Switch the order of the items in the from clause, and it should work.
Here's a test case that I knocked up to demonstrate (I used CLOBs since we're apparently dealing with text; I'm not sure why you're using BLOBs?):
create table t1 (id number,
clob_col clob);
insert into t1 values (1, 'abcd');
insert into t1 values (2, 'efg');
commit;
create type string_array is table of varchar2(255);
create or replace function clob_to_str_tab (p_clob in clob)
return string_array
is
v_str_arr string_array := string_array();
begin
for i in 1.. length(p_clob)
loop
v_str_arr.extend;
v_str_arr(i) := substr(p_clob, i, 1);
end loop;
return v_str_arr;
end;
/
select t1.id,
t2.column_value res
from table(clob_to_str_tab(t1.clob_col)) t2,
t1;
ORA-00904: "T1"."CLOB_COL": invalid identifier
select t1.id,
t2.column_value res
from t1,
table(clob_to_str_tab(t1.clob_col)) t2;
ID RES
---------- ---
1 a
1 b
1 c
1 d
2 e
2 f
2 g
You can achieve this with Oracle's PIPE ROW statement
See: Pipelined Table Functions
I am new in PostgreSQL and I wonder if it's possible to use number from table tbc as part of the table name in left join 'pa' || number. So for example if number is 456887 I want left join with table pa456887. Something like this:
SELECT tdc.cpa, substring(tdc.ku,'[0-9]+') AS number, paTab.vym
FROM public."table_data_C" AS tdc
LEFT JOIN concat('pa' || number) AS paTab ON (paTab.cpa = tdc.cpa)
And I want to use only PostgreSQL, not additional code in PHP for example.
Either way, you need dynamic SQL.
Table name as given parameter
CREATE OR REPLACE FUNCTION foo(_number int)
RETURNS TABLE (cpa int, nr text, vym text) AS -- adapt to actual data types!
$func$
BEGIN
RETURN QUERY EXECUTE format(
'SELECT t.cpa, substring(t.ku,'[0-9]+'), p.vym
FROM public."table_data_C" t
LEFT JOIN %s p USING (cpa)'
, 'pa' || _number
);
END
$func$ LANGUAGE plpgsql;
Call:
SELECT * FROM foo(456887)
Generally, you would sanitize table names with format ( %I ) to avoid SQL injection. With just an integer as dynamic input that's not necessary. More details and links in this related answer:
INSERT with dynamic table name in trigger function
Data model
There may be good reasons for the data model. Like partitioning / sharding or separate privileges ...
If you don't have such a good reason, consider consolidating multiple tables with identical schema into one and add the number as column. Then you don't need dynamic SQL.
Consider inheritance. Then you can add a condition on tableoid to only retrieve rows from a given child table:
SELECT * FROM parent_table
WHERE tableoid = 'pa456887'::regclass
Be aware of limitations for inheritance, though. Related answers:
Get the name of a row's source table when querying the parent it inherits from
Select (retrieve) all records from multiple schemas using Postgres
Name of 2nd table depending on value in 1st table
Deriving the name of the join table from values in the first table dynamically complicates things.
For only a few tables
LEFT JOIN each on tableoid. There is only one match per row, so use COALESCE.
SELECT t.*, t.tbl, COALESCE(p1.vym, p2.vym, p3.vym) AS vym
FROM (
SELECT cpa, ('pa' || substring(ku,'[0-9]+'))::regclass AS tbl
FROM public."table_data_C"
-- WHERE <some condition>
) t
LEFT JOIN pa456887 p1 ON p1.cpa = t.cpa AND p1.tableoid = t.tbl
LEFT JOIN pa456888 p2 ON p2.cpa = t.cpa AND p2.tableoid = t.tbl
LEFT JOIN pa456889 p3 ON p3.cpa = t.cpa AND p3.tableoid = t.tbl
For many tables
Combine a loop with dynamic queries:
CREATE OR REPLACE FUNCTION foo(_number int)
RETURNS TABLE (cpa int, nr text, vym text) AS
$func$
DECLARE
_nr text;
BEGIN
FOR _nr IN
SELECT DISTINCT substring(ku,'[0-9]+')
FROM public."table_data_C"
LOOP
RETURN QUERY EXECUTE format(
'SELECT t.cpa, _nr, p.vym
FROM public."table_data_C" t
LEFT JOIN %I p USING (cpa)
WHERE t.ku LIKE (_nr || '%')'
, 'pa' || _nr
);
END LOOP;
END
$func$ LANGUAGE plpgsql;