如何在where子句中使用计算的列值 [英] How to use calculated column value in where clause
本文介绍了如何在where子句中使用计算的列值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我需要检索按计算所得列的结果过滤的数据-如何?
INFORMIX:
I need to retrieve data filtered by the results of a calculated column - how?
INFORMIX:
SELECT
TUP_TAG_NO AS TAG,
(
CASE
(
CASE (SELECT ttt_prnt_tag_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no) WHEN NULL THEN (SELECT MIN(pkc_cmpt_tag_no) FROM INTPKC_REC WHERE pkc_pkg_ctl_no = tup_itm_ctl_no GROUP BY pkc_pkg_ctl_no) ELSE (SELECT ttt_prnt_tag_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no) END )
WHEN NULL
THEN (SELECT TRIM(tag_mst_tag_no) FROM INTTAG_REC WHERE tag_itm_ctl_no = tup_itm_ctl_no)
ELSE
(
CASE
(
SELECT tag_mst_tag_no
FROM
INTTAG_REC
WHERE tag_itm_ctl_no =
(
CASE (SELECT ttt_itm_ctl_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no)
WHEN NULL
THEN (SELECT MIN(pkc_cmpt_ctl_no) FROM INTPKC_REC WHERE pkc_pkg_ctl_no = tup_itm_ctl_no GROUP BY pkc_pkg_ctl_no)
ELSE (SELECT ttt_itm_ctl_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no)
END
)
)
WHEN NULL
THEN (SELECT TRIM(atg_mst_tag_no) FROM INAATG_REC WHERE atg_itm_ctl_no =
(
CASE (SELECT ttt_itm_ctl_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no)
WHEN NULL
THEN (SELECT MIN(pkc_cmpt_ctl_no) FROM INTPKC_REC WHERE pkc_pkg_ctl_no = tup_itm_ctl_no GROUP BY pkc_pkg_ctl_no)
ELSE (SELECT ttt_itm_ctl_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no)
END
)
)
ELSE
(
SELECT TRIM(tag_mst_tag_no)
FROM
INTTAG_REC
WHERE tag_itm_ctl_no =
(
CASE (SELECT ttt_itm_ctl_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no)
WHEN NULL
THEN (SELECT MIN(pkc_cmpt_ctl_no) FROM INTPKC_REC WHERE pkc_pkg_ctl_no = tup_itm_ctl_no GROUP BY pkc_pkg_ctl_no)
ELSE (SELECT ttt_itm_ctl_no FROM INTTTT_REC WHERE ttt_itm_ctl_no = tup_itm_ctl_no)
END
)
)
END
)
END
) AS MASTER_TAG,
FROM
TRJTUP_REC,
TRJTUD_REC,
TRJTPH_REC,
INRFSH_REC,
ARRCUS_REC,
TCTNAD_REC
WHERE
`MASTER` = '123456'
推荐答案
我不熟悉INFORMIX，但是它是在SQL Server中完成的，如下所示:
I''m not familiar with INFORMIX, but it is done in SQL Server as follows:
SELECT
(100 - YearsOld) AS YearsRemaining
FROM People
WHERE
(100 - YearsOld) > 0
也就是说，您在WHERE子句中输入计算.
That is, you enter the calculation in the WHERE clause.
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