问无法更改大查询中的列数据类型

EN

CREATE OR REPLACE TABLE testset.tbl AS 
SELECT 'a' AS col1, '2022-05-16' AS create_date
 UNION ALL
SELECT 'a' AS col1, '2022-05-14' AS create_date
;

-- ALTER TABLE testset.tbl ALTER COLUMN create_date SET DATA TYPE DATE;

-- Query error: ALTER TABLE ALTER COLUMN SET DATA TYPE requires that
-- the existing column type (STRING) is assignable to the new type (DATE) at [7:25]


-- Create it again. 
CREATE OR REPLACE TABLE testset.tbl AS
SELECT * REPLACE(SAFE_CAST(create_date AS DATE) AS create_date) 
  FROM testset.tbl;