Compute a boolean result of multiple value/operator from a database table

Normally one would process this using precedence rules: and comes before or, and this would complicate things immensely.

But if you want to process this in a very simple stack manner, where each item is processed in order, you can rearrange this in the following manner.

• Since (A AND B) OR C is the same as C OR (A AND B), we can simply look for all ands separately from or
• We can ignore any or condition which is false because any other condition will override it
• We need all and conditions to be true

SELECT CASE WHEN
        (COUNT(CASE WHEN Operator = 'and' AND value = 1 THEN 1 END) > 0
     AND COUNT(CASE WHEN Operator = 'and' AND value = 0 THEN 1 END) = 0)
  OR COUNT(CASE WHEN Operator = 'or' AND value = 1 THEN 1 END) > 0
  THEN 1 ELSE 0 END
FROM YourTable;

You say that actually you do want to use precedence rules. You have no brackets, so that makes things easier.

So we can formulate it like this:

• Any or which is false can be ignored
• Any or which is true overrides anything else
• Group all ands together in islands, and evaluate each island separately
• Any island of all trues is true, all others are false

SELECT CASE WHEN
  EXISTS (SELECT 1
    FROM YourTable t
    WHERE Operator = 'or' AND value = 1)
  OR EXISTS (SELECT 1
    FROM (
        SELECT *,
            ROW_NUMBER() OVER (ORDER BY ID) - 
            ROW_NUMBER() OVER (PARTITION BY Operator ORDER BY ID) grouping
        FROM YourTable t
    ) t
    WHERE Operator = 'and'
    GROUP BY grouping
    HAVING COUNT(CASE WHEN value = 0 THEN 1 END) = 0
  )
 THEN 1 ELSE 0 END;