Convert DB rules to if-else conditions? - sql-server

Question

I want to convert a set of rows in SQL Server database (In the form of rules) to a single if-else condition without hardcoding any values in the code. The code will be written in Scala and I am trying to figure out the logic to do this but could not think of a good approach.
Sample SQL Server Rows:
TAG | CONDITION | MIN VALUE | MAX VALUE | STATUS
ABC | = | 0 | NULL | GOOD
ABC | = | 1 | NULL | BAD
ABC | = | 2 | NULL | ERROR
ABC | >= | 3 | NULL | IGNORE
Similar to tag ABC, there could be any number of tags and the conditions will vary with the tag column and each tag will have conditions in multiple rows. If anyone has dealt with a similar problem and has any suggestions that would be appreciated.

Answer 1

The question doesn't seem clear to me as currently written. What do you mean by a "a single if-else condition without hardcoding any values in the code"?
Would the following work?
sealed trait Condition
object Eq extends Condition // =
object Ge extends Condition // >=
sealed trait Status
object Good extends Status
object Bad extends Status
object Error extends Status
object Ignore extends Status
case class Rule(tag: String,
condition: Condition,
min: Int,
max: Int,
status: Status)
def handle(input: Int, rules: List[Rule]): Status =
rules
.view // lazily iterate the rules
.filter { // find matching rules
case Rule(_, Eq, x, _, _) if input == x => true
case Rule(_, Ge, x, _, _) if input >= x => true
case _ => false
}
.map { matchingRule => matchingRule.status } // return the status
.head // find the status of the first matching rule, or throw
// Tests
val rules = List(
Rule("abc", Eq, 0, 0, Good),
Rule("abc", Eq, 1, 0, Bad),
Rule("abc", Eq, 2, 0, Error),
Rule("abc", Ge, 3, 0, Ignore))
assert(handle(0, rules) == Good)
assert(handle(1, rules) == Bad)
assert(handle(2, rules) == Error)
assert(handle(3, rules) == Ignore)
assert(handle(4, rules) == Ignore)