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SELECT
Id, empname, deptid, Salary,
SUM(Salary) OVER(PARTITION BY deptid) AS SUM_SAL
FROM
emp ORDER BY id
# Id, empname, deptid, Salary, SUM_SAL
'1', 'john', '1', '20000', '50000'
'2', 'kem', '1', '30000', '50000'
'3', 'chan', '2', '10000', '30000'
'4', 'henry', '2', '20000', '30000'
'5', 'bill', '3', '30000', '30000'
'6', 'salt', '4', '20000', '20000'