Hi everyone thanks so much for taking the time to read this.
I'd like to create a macro in Teradata that will create a table from another table based on specific parameters.
My original table consists of three columns patient_id, diagnosis_code and Date_of_birth
......
I'd like to build a macro that would allow me to specify a diagnosis code and it would then build the table consisting of data of all patients with that diagnosis code.
My current code looks like this
Create Macro All_pats (diag char) as (
create table pats as(
select *
from original_table
where diag = :diagnosis_code;)
with data primary index (patid);
I cant seem to get this to work - any tips?
Thanks once again
Your code has a semicolon in a wrong place and a missing closing bracket:
Create Macro All_pats (diag char) as (
create table pats as
(
select *
from original_table
where diag = :diagnosis_code
) with data primary index (patid);
);
Edit:
Passing multiple values as a delimited list is more complicated (unless you use Dynamic SQL in a Stored Procedure):
REPLACE MACRO All_lpats (diagnosis_codes VARCHAR( 1000)) AS
(
CREATE TABLE pats AS
(
SELECT *
FROM original_table AS t
JOIN TABLE (StrTok_Split_To_Table(1, :diagnosis_codes, ',')
RETURNS (outkey INTEGER,
tokennum INTEGER,
token VARCHAR(20) CHARACTER SET Unicode)
) AS dt
ON t.diag = dt.token
) WITH DATA PRIMARY INDEX (patid);
);
EXEC All_lpats('111,112,113');
As the name implies StrTok_Split_To_Table splits a delimited string into a table. You might need to adust the delimiter and the length of the resulting token.
Related
Product type table contains product types. Some ids may missing :
create table artliik (liiginrlki char(3) primary key);
insert into artliik values('1');
insert into artliik values('3');
insert into artliik values('4');
...
insert into artliik values('999');
Property table contais comma separated list of types.
create table strings ( id char(100) primary key, kirjeldLku chr(200) );
insert into strings values ('item1', '1,4-5' );
insert into strings values ('item2', '1,2,3,6-9,23-44,45' );
Type can specified as single integer, e.q 1,2,3 or as range like 6-9 or 23-44
List can contain both of them.
How to all properties for given type.
Query
select id
from artliik
join strings on ','||trim(strings.kirjeldLku)||',' like '%,'||trim(artliik.liiginrlki)||',%'
returns date for single integer list only.
How to change join so that type ranges in list like 6-9 are also returned?
Eq. f list contains 6-9, Type 6,7,8 and 9 shoud included in report.
Postgres 13 is used.
I would suggest a helper function similar to unnest that honors ranges.
Corrected function
create or replace function unnest_ranges(s text)
returns setof text language sql immutable as
$$
with t(x) as (select unnest(string_to_array(s, ',')))
select generate_series
(
split_part(x, '-', 1)::int,
case when x ~ '-' then split_part(x, '-', 2)::int else x::int end,
1
)::text
from t;
$$;
Then you can 'normalize' table strings and join.
select *
from artliik a
join (select id, unnest_ranges(kirjeldLku) from strings) as t(id, v)
on a.liiginrlki = v;
The use of a function definition is of course optional. I prefer it because the function is generic and reusable.
dbfiddle.uk demo will only works on pg14, since only pg14 have multirange data type. But customizeable icu collation works in pg13.
Collation doc: https://www.postgresql.org/docs/current/collation.html
Idea: create a multirange text data type that will sort numeric value based on their numerical value. like 'A-21' < 'A-123'.
CREATE COLLATION testcoll_numeric (
provider = icu,
locale = '#colNumeric=yes'
);
CREATE TYPE textrange AS RANGE (
subtype = text,
multirange_type_name = mulitrange_of_text,
COLLATION = testcoll_numeric
);
So
SELECT
mulitrange_of_text (textrange ('1'::text, '11'::text)) #> '9'::text AS contain_9;
should return true.
artliik table structure remain the same, but strings table need to change a bit.
CREATE temp TABLE strings (
id text PRIMARY KEY,
kirjeldLku mulitrange_of_text
);
then query it:
SELECT DISTINCT
strings.id
FROM
artliik,
strings
WHERE
strings.kirjeldLku #> liiginrlki::text
ORDER BY
1;
I am working on a sql database which will provide with data some grid. The grid will enable filtering, sorting and paging but also there is a strict requirement that users can enter free text to a text input above the grid for example
'Engine 1001 Requi' and that the result will contain only rows which in some columns contain all the pieces of the text. So one column may contain Engine, other column may contain 1001 and some other will contain Requi.
I created a technical column (let's call it myTechnicalColumn) in the table (let's call it myTable) which will be updated each time someone inserts or updates a row and it will contain all the values of all the columns combined and separated with space.
Now to use it with entity framework I decided to use a table valued function which accepts one parameter #searchQuery and it will handle it like this:
CREATE FUNCTION myFunctionName(#searchText NVARCHAR(MAX))
RETURNS #Result TABLE
( ... here come columns )
AS
BEGIN
DECLARE #searchToken TokenType
INSERT INTO #searchToken(token) SELECT value FROM STRING_SPLIT(#searchText,' ')
DECLARE #searchTextLength INT
SET #searchTextLength = (SELECT COUNT(*) FROM #searchToken)
INSERT INTO #Result
SELECT
... here come columns
FROM myTable
WHERE (SELECT COUNT(*) FROM #searchToken WHERE CHARINDEX(token, myTechnicalColumn) > 0) = #searchTextLength
RETURN;
END
Of course the solution works fine but it's kinda slow. Any hints how to improve its efficiency?
You can use an inline Table Valued Function, which should be quite a lot faster.
This would be a direct translation of your current code
CREATE FUNCTION myFunctionName(#searchText NVARCHAR(MAX))
RETURNS TABLE
AS RETURN
(
WITH searchText AS (
SELECT value token
FROM STRING_SPLIT(#searchText,' ') s(token)
)
SELECT
... here come columns
FROM myTable t
WHERE (
SELECT COUNT(*)
FROM searchText
WHERE CHARINDEX(s.token, t.myTechnicalColumn) > 0
) = (SELECT COUNT(*) FROM searchText)
);
GO
You are using a form of query called Relational Division Without Remainder and there are other ways to cut this cake:
CREATE FUNCTION myFunctionName(#searchText NVARCHAR(MAX))
RETURNS TABLE
AS RETURN
(
WITH searchText AS (
SELECT value token
FROM STRING_SPLIT(#searchText,' ') s(token)
)
SELECT
... here come columns
FROM myTable t
WHERE NOT EXISTS (
SELECT 1
FROM searchText
WHERE CHARINDEX(s.token, t.myTechnicalColumn) = 0
)
);
GO
This may be faster or slower depending on a number of factors, you need to test.
Since there is no data to test, i am not sure if the following will solve your issue:
-- Replace the last INSERT portion
INSERT INTO #Result
SELECT
... here come columns
FROM myTable T
JOIN #searchToken S ON CHARINDEX(S.token, T.myTechnicalColumn) > 0
Query:
CREATE TABLE SRC(SRC_STRING VARCHAR(20))
CREATE OR REPLACE TABLE TGT(tgt_STRING VARCHAR(10))
INSERT INTO SRC VALUES('JKNHJYGHTFGRTYGHJ')
INSERT INTO TGT(TGT_STRING) SELECT SRC_STRING::VARCHAR(10) FROM SRC
Error: String 'JKNHJYGHTFGRTYGHJ' is too long and would be truncated
Is there any way we can enable enforce length(not for COPY command) while inserting data from high precision to low precision column?
I'd recommend using the SUBSTR( ) function, to pick the piece of data you want, example as follows where I take the first 10 characters (if available, if there were only 5 it'd use those 5 characters).
CREATE OR REPLACE TEMPORARY TABLE SRC(
src_string VARCHAR(20));
CREATE OR REPLACE TEMPORARY TABLE TGT(
tgt_STRING VARCHAR(10));
INSERT INTO src
VALUES('JKNHJYGHTFGRTYGHJ');
INSERT INTO tgt(tgt_string)
SELECT SUBSTR(src_string, 1, 10)
FROM SRC;
SELECT * FROM tgt; --JKNHJYGHTF
Here's the documentation on the function:
https://docs.snowflake.com/en/sql-reference/functions/substr.html
Can I do something like this, column is of type nchar(8), but the string I wanted to store in the table is longer than that.
The reason I am doing this is because I want to convert from one table to another table. Table A is nchar(8) and Table B is nvarchar(100). I want all characters in Table B transfer to Table A without missing any single character.
If the nvarchar(100) contains only latin characters with a length up to 16 chars, then you can squeeze the nvarchar(100) into the nchar(8):
declare #t table
(
col100 nvarchar(100),
col8 nchar(8)
);
insert into #t(col100) values('1234567890123456');
update #t
set col8 = cast(cast(col100 as varchar(100)) as varbinary(100))
select *, cast(cast(cast(col8 as varbinary(100)) as varchar(100)) as nvarchar(100)) as from8to100_16charsmax
from #t;
If you cannot modify A, then you cannot use it to store the data. Create another table for the overflow . . . something like:
create table a_overflow (
a_pk int primary key references a(pk),
column nvarchar(max) -- why stop at 100?
);
Then, you can construct a view to bring in the data from this table when viewing a:
create view vw_a as
select . . . , -- all the other columns
coalesce(ao.column, a.column) as column
from a left join
a_overflow ao
on ao.a_pk = a.pk;
And, if you really want to "hide" the view, you can create an insert trigger on vw_a, which inserts the appropriate values into the two tables.
This is a lot of work. Simply modifying the table is much simpler. That said, this approach is sometimes needed when you need to modify a large table and altering a column would incur too much locking overhead.
I have a table designed like,
create table tbl (
id number(5),
data blob
);
Its found that the column data have
very small size data, which can be stored in raw(200):
so the new table would be,
create table tbl (
id number(5),
data raw(200)
);
How can I migrate this table to new design without loosing the data in it.
This is a bit lengthy method, but it works if you are sure that your data column values don't go beyond 200 in length.
Create a table to hold the contents of tbl temporarily
create table tbl_temp as select * from tbl;
Rem -- Ensure that tbl_temp contains all the contents
select * from tbl_temp;
Rem -- Double verify by subtracting the contents
select * from tbl minus select * from tbl_temp;
Delete the contents in tbl
delete from tbl;
commit;
Drop column data
alter table tbl drop column data;
Create a column data with raw(200) type
alter table tbl add data raw(200);
Select & insert from the temporary table created
insert into tbl select id, dbms_lob.substr(data,200,1) from tbl_temp;
commit;
We are using substr method of dbms_lob package which returns raw type data. So, the resulted value can be directly inserted.