sql - SQL DB2 - Possible to shorten long-listed 'case when' statement?

Question

Sometimes my queries have long case when statements. For example,

CASE WHEN BASE_YM = TO_CHAR(DEFAULT_YM,            'YYYYMM') THEN '00'
     WHEN BASE_YM = TO_CHAR(DEFAULT_YM - 1 MONTHS, 'YYYYMM') THEN '01'
     WHEN BASE_YM = TO_CHAR(DEFAULT_YM - 2 MONTHS, 'YYYYMM') THEN '02'
     .
     .
     .
     WHEN BASE_YM = TO_CHAR(DEFAULT_YM - 35 MONTHS, 'YYYYMM') THEN '35'
     WHEN BASE_YM = TO_CHAR(DEFAULT_YM - 36 MONTHS, 'YYYYMM') THEN '36'

This case when statement itself takes up 37lines and I was wondering if there might be maybe a way to shorten the case when statement by using i=00, ..., 36 something like that?

Answer 1

36 行の個別の値を含む 2 つの列を持つ新しいテーブルを作成し、それを結合しますか? これにより、case ステートメントがまったく不要になります。