Case Statement Error when using MINUS Snowflake DB

I´m trying to change a specific date to a other one in order to compare the hash values of two queries. For that I´m using the CASE statement. But I can´t understand why I´m getting the following error

The column DATE_VALUE has the data type DATE and I´m operating on a Snowflake Database

inconsistent data type for result columns for set operator input branches, expected DATE, got BOOLEAN for expression [{2}] branch {3}

SQL statement

SELECT COL
, CASE WHEN DATE_VALUE = '2021-01-10' THEN DATE_VALUE = CAST('2021-01-11' AS DATE)
END AS DATE_VALUE
,HASH(
CASE WHEN DATE_VALUE = '2021-01-10'::DATE THEN DATE_VALUE= '2021-01-11'::DATE
END
, COL
, COL
, COL
, COL
, COL
, COL
, COL
)
FROM TABLE1
MINUS
SELECT
COL
, DATE_VALUE
, HASH(
DATE_VALUE
, COL
, COL
, COL
, COL
, COL
, COL
, COL
)
FROM TABLE2;

2 Answers

You have this expression for the second column:

(CASE WHEN DATE_VALUE = '2021-01-10' THEN DATE_VALUE = CAST('2021-01-11' AS DATE) END) AS DATE_VALUE

The THEN clause is:

DATE_VALUE = CAST('2021-01-11' AS DATE)

This is a boolean expression, not a date expression. You seem to want:

(CASE WHEN DATE_VALUE = '2021-01-10' THEN CAST('2021-01-11' AS DATE) END) AS DATE_VALUE

Or:

(CASE WHEN DATE_VALUE = '2021-01-10' THEN '2021-01-11'::DATE END) AS DATE_VALUE

CASE..WHEN is incorrect.

It should be

CASE WHEN DATE_VALUE = '2021-01-10' THEN CAST('2021-01-11' AS DATE) -- DATE_VALUE = CAST('2021-01-11' AS DATE) returns boolean not date
END AS DATE_VALUE