SQL update select结合语句

UPDATE "his_system_medcine_frequency" A
SET A ."input_code" = (
SELECT
b.INPUT_CODE
FROM
COM_DICTIONARY b
WHERE
TYPE = 'YBTS.FreCompare'
and     A ."frequency_code" = b.CODE
)

UPDATE "his_system_medcine_frequency" A
SET A ."input_code" = (
SELECT
b.INPUT_CODE
FROM
COM_DICTIONARY b
WHERE
TYPE = 'YBTS.FreCompare'
)
WHERE
A ."frequency_code" = b.CODE

1 --------(MS SQL Server)语句：
2 update b   set   ClientName    = a.name    from a,b    where a.id = b.id
3
4 --------(Oralce)语句：
5 update b   set   (ClientName)    =   (SELECT name FROM a WHERE b.id = a.id)