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;
/
Related
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
T_TABLE_N := UPPER(TABLE_N);
FOR ATTRIBUTE_ IN (SELECT HEADER_NAME FROM T_TABLE_N
GROUP BY HEADER_NAM )
Here, I use the T_TABLE_N table as a variable. But it wasn't taken as a table
How to solve this problem
I have a database with the column "endpointid" in a lot of tables. I am looking for a search function that would find every table containing a specific endpointid in order to write a query to delete that endpoint. I have tried a delete function to delete it from all tables but that is not working properly since a specific endpointid might not be in all tables. I know the following query gives all tables with the column name:
select table_name from all_tab_columns where lower(column_name) like lower('%endpointid%');
How can I extend that query to search for a specific record of endpointid?
Here is an example to delete rows with a specific endpointid value:
CREATE TABLE mytest (
endpointid NUMBER
);
INSERT INTO mytest VALUES ( 1 );
INSERT INTO mytest VALUES ( 2 );
DECLARE
ep NUMBER := 2;
BEGIN
FOR t_rec IN (
SELECT
table_name
FROM
all_tab_columns
WHERE
lower(column_name) LIKE lower('%endpointid%')
) LOOP
EXECUTE IMMEDIATE 'delete from '
|| t_rec.table_name
|| ' where endpointid = :1'
USING ep;
END LOOP;
END;
Note that if these tables have foreign key relationships, this may fail, as it does not take into account the ordering of the table references. If that is needed, then you would need to structure your metatada query to find those relationships.
Is there a way to select a field from a table and if that field doesn't exist then select a different field from the same table? example:
SELECT MY_FIELD from MY_TABLE
error: "MY_FIELD": invalid identifier
is there any way to check if it exists and if it does then use that field for the query, if it doesn't exist then use example:
SELECT my_field2 from client.
My problem is
I am writing a report that will be used on two databases, but the field names on occasion can be named slightly different depending on the database.
What you really need to do is talk to your management / development leads about why the different databases are not harmonized. But, since this is a programming site, here is a programming answer using dynamic SQL.
As has been pointed out, you could create views in the different databases to provide yourself with a harmonized layer to query from. If you are unable to create views, you can do something like this:
create table test ( present_column NUMBER );
insert into test select rownum * 10 from dual connect by rownum <= 5;
declare
l_rc SYS_REFCURSOR;
begin
BEGIN
OPEN l_rc FOR 'SELECT missing_column FROM test';
EXCEPTION
WHEN others THEN
OPEN l_rc FOR 'SELECT present_column FROM test';
END;
-- This next only works in 12c and later
-- In earlier versions, you've got to process l_rc on your own.
DBMS_SQL.RETURN_RESULT(l_rc);
end;
This is inferior to the other solutions (either harmonizing the databases or creating views). For one thing, you get no compile time checking of your queries this way.
That won't compile, so - I'd say not. You might try with dynamic SQL which reads contents of the USER_TAB_COLUMNS and create SELECT statement on-the-fly.
Depending on reporting tool you use, that might (or might not) be possible. For example, Apex offers (as reports's source) a function that returns query, so you might use it there.
I'd suggest a simpler option - create views on both databases which have unified column names, so that your report always selects from the view and works all the time. For example:
-- database 1:
create view v_client as
select client_id id,
client_name name
from your_table;
-- database 2:
create view v_client as
select clid id,
clnam name
from your_table;
-- reporting tool:
select id, name
from v_client;
This can be done in a single SQL statement using DBMS_XMLGEN.GETXML, but it gets messy. It would probably be cleaner to use dynamic SQL or a view, but there are times when it's difficult to create supporting objects.
Sample table:
--Create either table.
create table my_table(my_field1 number);
insert into my_table values(1);
insert into my_table values(2);
create table my_table(my_field2 number);
insert into my_table values(1);
insert into my_table values(2);
Query:
--Get the results by converting XML into rows.
select my_field
from
(
--Convert to an XMLType.
select xmltype(clob_results) xml_results
from
(
--Conditionally select either MY_FIELD1 or MY_FIELD2, depending on which exists.
select dbms_xmlgen.GetXML('select my_field1 my_field from my_table') clob_results
from user_tab_columns
where table_name = 'MY_TABLE'
and column_name = 'MY_FIELD1'
--Stop transformations from running the XMLType conversion on nulls.
and rownum >= 1
union all
select dbms_xmlgen.GetXML('select my_field2 my_field from my_table') clob_results
from user_tab_columns
where table_name = 'MY_TABLE'
and column_name = 'MY_FIELD2'
--Stop transformations from running the XMLType conversion on nulls.
and rownum >= 1
)
--Only convert non-null values.
where clob_results is not null
)
cross join
xmltable
(
'/ROWSET/ROW'
passing xml_results
columns
my_field number path 'MY_FIELD'
);
Results:
MY_FIELD
--------
1
2
Here's a SQL Fiddle if you want to see it running.
I want to get data from table which name is keeping in another table. Trying to get this as described below leads to getting result from nested SELECT only
select * from (select value from ex_scheme.ex_tab where name = 'ex_name.current_table_name')
I mean, I've got equivalent result as from just
select value from ex_scheme.ex_tab where name = 'ex_name.current_table_name'
query.
UPDATED
Ok, lets double-check if I was correctly understood.
I have to see one table data (lets call this table "table1"). I need to know this table name. And I know where its name is keeping. It is in another table (call it "names_table") in column "name" (row with column value = 'table1'). And I can get it by query
select name from names_table where value = 'table1'
If you know in advance the column and its type, you can build some dynamic SQL to dynamically query a table or another.
For example, say you have tables like the following:
create table table1(col) as (select 1 from dual);
create table table2(col) as (select 2 from dual);
create table tab_of_tabs (tab_name) as (select 'TABLE1' from dual);
You can use dynamic SQL to build a query that scans a table whose name is the result of a query:
SQL> declare
2 vSQL varchar2(1000);
3 vResult number;
4 begin
5 select 'select sum(col) from ' || tab_name -- build the query
6 into vSQL
7 from tab_of_tabs;
8 --
9 execute immediate vSQL into vResult; -- run the query
10 --
11 dbms_output.put_line('Result: ' || vResult);
12 end;
13 /
Result: 1
PL/SQL procedure successfully completed.
SQL>
If I understand correctly, you could use a nested query in a where clause. For example,
select * from table1 where table1.name in (select name from table2);
This assumes there's a column "name" in table1. The result of this query should return the rows in table1 that are in table2.
try giving alias
select n.* from (select value from ex_scheme.ex_tab where name = 'ex_name.current_table_name') n;
Update:
It is in another table (call it "names_table") in column "name" (row
with column value = 'table1').
this query will work
select n.* from (select name from ex_scheme.ex_tab where name = 'ex_name.current_table_name') n;
sub query fetches name of table from another table .