[SQL] Dynamic SQL in WHERE clause

SELECT A.COL1, A.COL2, A.COL3, A.COL4
FROM TABLE A, TABLE B
WHERE B.COL1 = A.COL1
AND B.COL2 = A.COL2
AND B.COL3 - A.COL3
AND B.COL4 = A.COL4


Now I want to tune the SQL query, that whenever any of the Columns in Table B has field value 'ALL' the where clause will not come into picture.

i.e. When it has a distinct value it will match with both the tables, when the field value is 'ALL' then to exclude from the where clause.

Alternatively,

I Need B.COL1= A.COL1 (When B.COL1 <> 'ALL')
Else NO WHERE clause with B.Col1 = A.Col1 (When B.COL1 = 'ALL')

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