Unknown column in Having Clause Getting this apparently nonsensical error
Error code: 1054 Unknown column in having Clause

while running this query
Select date(START_TS), resource_key, count(INTERACTION_RESOURCE_ID) 
From tableName
Group By date(START_TS), resource_key 
Having date(START_TS) &gt; '2020-08-27' and resource_key in(772122, 772134);

Although the objective has been achieved by using Where Clause before Group By, but this error is still bothering. Any help would be appreciated.
Havin can only use colmuns that are in the GROUP By or SELECT. But START_TS as columns doesn't exist, so you must use an ALIAS  to get your dates.
Schema (MySQL v5.7)
CREATE TABLE tableName (
  `START_TS` date,
  `resource_key` int,
  `INTERACTION_RESOURCE_ID` varchar(4)
);

INSERT INTO tableName
  (`START_TS`, `resource_key`, `INTERACTION_RESOURCE_ID`)
VALUES
  ('2020-08-27' , 772122, 'test'),
    ('2020-08-27' , 772122, 'test')
;


Query #1
Select date(START_TS) date_ts, MIN(resource_key), count(INTERACTION_RESOURCE_ID) 
From tableName
Group By date(START_TS), resource_key 
Having date_ts &gt;= '2020-08-27' and resource_key in (772122, 772134);

| date_ts    | MIN(resource_key) | count(INTERACTION_RESOURCE_ID) |
| ---------- | ----------------- | ------------------------------ |
| 2020-08-27 | 772122            | 2                              |


View on DB Fiddle