Convert comma separated string to a list

Question

I want to pass a list of int's (comma separated) which is a field in my table

ie. 1234, 2345, 3456, 4567

to my IN clause in WHERE. But the list is a string (VARCHAR), and I'm comparing to an int field. Is there a way for me to convert the list to list of ints?

Enterprise_ID is INT
Path is a field in the table which is a comma separated string

ie. 1234, 2345, 3456, 4567

SELECT *
FROM tbl_Enterprise
WHERE Enterprise_ID IN ( Path )

My database is Vertica.

Answer 1

You can use SPLIT_PART function in vertica to split the comma separated list into rows and insert them into a temp table. Use a query something like this to achieve your goal:

SELECT * FROM tbl_Enterprice WHERE Enterprice_ID IN ( Select Enterprice_ID from temp_table )

Split part function: https://my.vertica.com/docs/7.1.x/HTML/Content/Authoring/SQLReferenceManual/Functions/String/SPLIT_PART.htm

Here is a example of splitting string into rows using split_part:

dbadmin=> SELECT SPLIT_PART('JIM|TOM|PATRICK|PENG|MARK|BRIAN', '|', row_num) "User Names"
dbadmin->   FROM (SELECT ROW_NUMBER() OVER () AS row_num
dbadmin(>           FROM tables) row_nums
dbadmin->  WHERE SPLIT_PART('JIM|TOM|PATRICK|PENG|MARK|BRIAN', '|', row_num) <> '';
 User Names
------------
 JIM
 TOM
 PATRICK
 PENG
 MARK
 BRIAN
(6 rows)

Answer 2

I would consider these two solutions to be anti-patterns and would recommend testing them for performance.

The first method uses functions that come in the flex table package.

SELECT values::INT as var1
FROM (
    SELECT MapItems(v1) OVER () AS (keys, values)
    FROM (
        SELECT MapDelimitedExtractor( '1234, 2345, 3456, 4567' 
                                       USING PARAMETERS DELIMITER=',') AS v1
    ) AS T
) AS T2
WHERE REGEXP_SUBSTR(values,'\d+',1) IS NOT NULL;
 var1 
------
 1234
 2345
 3456
 4567
(4 rows)

The second method uses functions that comes in the text index package.

SELECT words::INT AS var1 
FROM (
    SELECT TxtIndex.StringTokenizerDelim('1234, 2345, 3456, 4567',',') 
           OVER() AS (words, input_string)
) AS T
WHERE REGEXP_SUBSTR(words, '\d+',1) IS NOT NULL;
 var1 
------
 1234
 2345
 3456
 4567
(4 rows)