IF (CASE WHEN %new.line_abbrev IS NULL THEN 0 ELSE 1 END
      + CASE WHEN %new.product_category IS NULL THEN 0 ELSE 1 END) <> 1 THEN
    RAISERROR 18251 '%TriggerName: Must have a value for only one of LINE_ABBREV and PRODUCT_CATEGORY (the other must be NULL).';
  END IF;
  IF %new.line_abbrev IS NULL AND %new.group_code IS NOT NULL THEN
    RAISERROR 18252 '%TriggerName: Cannot have value for GROUP_CODE without a value for LINE_ABBREV.';
  END IF;
  IF (CASE WHEN %new.price_level IS NULL THEN 0 ELSE 1 END
      + CASE WHEN %new.ref_price_sheet_cd IS NULL THEN 0 ELSE 1 END) <> 1 THEN
    RAISERROR 18253 '%TriggerName: Must have a value for exactly one of PRICE_LEVEL and REF_PRICE_SHEET_CD (the other must be NULL).';
  END IF;
  IF (CASE WHEN %new.ref_price_sheet_cd IS NULL THEN 0 ELSE 1 END
      + CASE WHEN %new.markup_percent IS NULL THEN 0 ELSE 1 END) = 1 THEN
    RAISERROR 18254 '%TriggerName: Either REF_PRICE_SHEET_CD and MARKUP_PERCENT both must have a value or neither must have a value.';
  END IF;
  IF %new.effective_from_date > %new.effective_to_date THEN
    RAISERROR 18255 '%TriggerName: EFFECTIVE_TO_DATE cannot be earlier than EFFECTIVE_FROM_DATE.';
  END IF;

  IF %new.line_abbrev IS NOT NULL THEN
    -- Prevent updates if there are any conflicting records.  The user must clean up any conflicts before updating.
    IF EXISTS (SELECT * FROM %TableName
        WHERE customer_segment_id = %new.customer_segment_id
          AND product_category IS NULL
          AND line_abbrev = %new.line_abbrev
          AND ISNULL(group_code, -1) = ISNULL(%new.group_code, -1)
          AND (
              effective_from_date BETWEEN %new.effective_from_date AND %new.effective_to_date
              OR effective_to_date BETWEEN %new.effective_from_date AND %new.effective_to_date
              OR %new.effective_from_date BETWEEN effective_from_date AND effective_to_date
            )
          AND id <> %new.id
      ) THEN
      RAISERROR 18260 '%TriggerName: Record with conflicting criteria already exists.';
    END IF;
  ELSE
    -- Prevent updates if there are any conflicting records.  The user must clean up any conflicts before updating.
    IF EXISTS (SELECT * FROM %TableName
        WHERE customer_segment_id = %new.customer_segment_id
          AND product_category = %new.product_category
          AND line_abbrev IS NULL
          AND group_code IS NULL
          AND (
              effective_from_date BETWEEN %new.effective_from_date AND %new.effective_to_date
              OR effective_to_date BETWEEN %new.effective_from_date AND %new.effective_to_date
              OR %new.effective_from_date BETWEEN effective_from_date AND effective_to_date
            )
          AND id <> %new.id
      ) THEN
      RAISERROR 18260 '%TriggerName: Record with conflicting criteria already exists.';
    END IF;
  END IF;