Column with keywords found in comments field - teradata

Question

At work I've been given a task that I'm told is "simple and straightforward", but I'm having difficulty with:
I have a view that contains 4 columns, a PK, FK, comments, and column #4. My manager is telling me to make a table that contains 75 or so keywords, and then a query that will go through each row in the view, compare the comments to the keyword table, and then append each found keyword to column #4. I've searched google and SO, and have not found a query that would do this. Any help would be appreciated.

Answer 1

Try below. I am new to Teradata.
--***************************************************************
DROP TABLE x;
--***************************************************************
CREATE MULTISET VOLATILE TABLE x, NO FALLBACK,
CHECKSUM = DEFAULT,
LOG
(
RCD_ID INTEGER,
FK INTEGER,
CMT VARCHAR(200),
COL_4 VARCHAR(200),
RN INTEGER
)
PRIMARY INDEX (RCD_ID)
ON COMMIT PRESERVE ROWS;
--***************************************************************
INSERT INTO x VALUES (1,10,'DID YOU SEE THE COW?','',0);
INSERT INTO x VALUES (2,20,'DID YOU SEE THE CAT?','',0);
INSERT INTO x VALUES (3,30,'DID YOU SEE THE FOX?','',0);
INSERT INTO x VALUES (4,40,'DID YOU SEE THE GOAT, FOX, AND CAT?','',0);
INSERT INTO x VALUES (5,50,'DID YOU SEE THE DUCK AND THE COW?','',0);
--***************************************************************
SELECT * FROM x ORDER BY 1;
--***************************************************************
DROP TABLE y;
--***************************************************************
CREATE MULTISET VOLATILE TABLE y, NO FALLBACK,
CHECKSUM = DEFAULT,
LOG
(
RCD_ID INTEGER,
KEY_WORD VARCHAR(20)
)
PRIMARY INDEX (RCD_ID)
ON COMMIT PRESERVE ROWS;
--***************************************************************
INSERT INTO y VALUES (1,'COW');
INSERT INTO y VALUES (2,'CAT');
INSERT INTO y VALUES (3,'FOX');
INSERT INTO y VALUES (4,'GOAT');
INSERT INTO y VALUES (5,'DUCK');
--***************************************************************
SELECT * FROM y ORDER BY 1;
--***************************************************************
DROP TABLE z;
--***************************************************************
CREATE MULTISET VOLATILE TABLE z AS(
SELECT x.RCD_ID,x.CMT,x.COL_4,y.key_word, ROW_NUMBER() OVER(PARTITION BY x.RCD_ID ORDER BY x.RCD_ID) AS RN
FROM x JOIN y ON x.cmt LIKE '%' || y.KEY_WORD || '%'
)
WITH DATA PRIMARY INDEX (RCD_ID)
ON COMMIT PRESERVE ROWS;
--***************************************************************
SELECT * FROM z ORDER BY 1,5;
--***************************************************************
WITH RECURSIVE RPT AS(
SELECT
RCD_ID,FK,CMT,COL_4,RN
FROM x
UNION ALL
SELECT
b.RCD_ID,b.FK,b.CMT,b.COL_4 || ';' || a.KEY_WORD,a.RN
FROM z AS a
JOIN RPT AS b
ON b.RCD_ID = a.RCD_ID
AND b.RN = a.RN-1
)
SELECT *
FROM RPT
QUALIFY ROW_NUMBER() OVER (PARTITION BY RCD_ID ORDER BY RCD_ID, RN DESC) = 1
ORDER BY 1,5;
--***************************************************************