[英]PostgreSQL and joining using character varying[] fields
我继承了PostgreSQL 9.2.4数据库,虽然我在SQL Server中拥有相当丰富的背景知识,但是在解决我遇到的问题时遇到了一些麻烦。
我有一个表,其中包含三个字段(除其他外)。 “ age_years”,“ age_months”和“ age_days”。 如果表格中的某人年龄小于或等于2个月,则他们在“ age_days”字段中具有其所占天数的值。 如果它们小于3岁但大于2个月,则它们在“ age_months”字段中具有一个值。 年龄大于3且在“ age_years”字段中具有值的任何值。
给定记录在这三个字段之一中仅具有非零值。 永远不会存在age_days和age_years都具有非零值的情况。 这些记录代表医院就诊,年龄是就诊时个人的年龄。
在另一个表中,我有几个最多包含20个值的character changes []字段。 它们是ref_age_cd,ref_age,ref_clow和ref_chigh。 这是该表中的示例记录(仅出于显示目的,其值比最大值少):
我为以下丑陋的道歉。 我似乎无法让它们以非常易读的格式进行格式化。
ref_age_cd | ref_age | ref_clow | ref_chigh
[D,D,D,M,M,Y,Y,Y] [1,4,15,2,7,13,18,199] [9.1,9.8,5.4,5.5,7.9,5.1,4.8,4.8] [27.1,27.8,16.4,15.8,15.9,11.1,10.8,10.8]
ref_age_cd字段确定您要查看的年龄(天,月或年)。 ref_age确定该值,然后根据这两个值从ref_clow和ref_chigh字段中获得低值和高值。 因此,例如,如果某人的age_months字段中有13,则您可以查看ref_age_cd并在数组中找到'M'值,然后查看相应的ref_age字段并找到低于该值的最大值age_months字段。 因此,数组索引将为5。然后在ref_clow和ref_chigh字段中获取低值和高值的第五个值。 (分别为7.9和15.9)
如果某人年龄为10天,则要查看的数组索引将为2(“ D”的ref_age_cd和ref_age为4)。 这将指示9.8和27.8的低值和高值。 如果他们80岁,则索引将为7(“ Y”的ref_age_cd和18的ref_age)。 低值和高值分别为4.8和10.8。
我只是不知道如何编程,因此当我从表A(具有age_days,age_months或age_years字段)加入参考表时,可以为ref_clow和ref_chigh拉正确的数组索引。
我还应该提到,我无法对该数据库进行任何更改。 我需要根据所给的知识进行这项工作。
对于单个患者,请尝试以下操作:
/* Creating test environment
CREATE TABLE refs (
id serial NOT NULL,
ref_age_cd character(1)[],
ref_age integer[],
ref_clow double precision[],
ref_chigh double precision[],
CONSTRAINT refs_pkey PRIMARY KEY (id)
);
INSERT INTO refs(ref_age_cd, ref_age, ref_clow, ref_chigh)
VALUES ('{"D","D","D","M","M","Y","Y","Y"}',
'{1,4,15,2,7,13,18,199}',
'{9.1,9.8,5.4,5.5,7.9,5.1,4.8,4.8}',
'{27.1,27.8,16.4,15.8,15.9,11.1,10.8,10.8}');
CREATE TABLE pats (
id serial NOT NULL,
name varchar(255) NOT NULL,
age_years integer,
age_months integer,
age_days integer,
CONSTRAINT pats_pkey PRIMARY KEY (id)
);
INSERT INTO pats
VALUES (DEFAULT, 'newborn', NULL, NULL, 10),
(DEFAULT, 'baby', NULL, 13, NULL),
(DEFAULT, 'adult', 80, NULL, NULL);
*/
-- Replace filters here to select only one row...
WITH tt AS ( SELECT * FROM refs WHERE id = 1 )
SELECT w.*, ref_clow, ref_chigh
FROM ( SELECT row_number() OVER () AS nr, unnest AS ref_age_cd
FROM UNNEST( (SELECT ref_age_cd FROM tt ) ), tt ) q1
JOIN ( SELECT row_number() OVER () AS nr, unnest AS ref_age
FROM UNNEST( (SELECT ref_age FROM tt ) ), tt ) q2 USING ( nr )
JOIN ( SELECT row_number() OVER () AS nr, unnest AS ref_clow
FROM UNNEST( (SELECT ref_clow FROM tt ) ), tt ) q3 USING ( nr )
JOIN ( SELECT row_number() OVER () AS nr, unnest AS ref_chigh
FROM UNNEST( (SELECT ref_chigh FROM tt ) ), tt ) q4 USING ( nr )
JOIN ( SELECT id, name, age_years, age_months, age_days,
CASE WHEN age_years IS NOT NULL THEN 'Y'
WHEN age_months IS NOT NULL THEN 'M'
WHEN age_days IS NOT NULL THEN 'D' END AS ref_age_cd,
CASE WHEN age_years IS NOT NULL THEN age_years
WHEN age_months IS NOT NULL THEN age_months
WHEN age_days IS NOT NULL THEN age_days END AS age
-- Replace filters here to select only one row...
FROM pats WHERE id = 2
) w USING (ref_age_cd)
WHERE ref_age <= age
ORDER BY ref_age DESC
LIMIT 1;
输出:
2;"baby";<NULL>;13;<NULL>;"M";13;7.9;15.9
最终达到目的。 发布,以便其他人可以使用它。
--test data in first two "with" statements
with a AS (
select 1 AS patient_nr, CAST(2 AS INT) AS age_days, CAST(NULL AS INT) AS age_months, CAST(NULL AS INT) AS age_years
UNION ALL
select 2 AS patient_nr, CAST(16 AS INT) AS age_days, CAST(NULL AS INT) AS age_months, CAST(NULL AS INT) AS age_years
UNION ALL
select 3 AS patient_nr, CAST(NULL AS INT) AS age_days, CAST(13 AS INT) AS age_months, CAST(NULL AS INT) AS age_years
UNION ALL
select 4 AS patient_nr, CAST(10 AS INT) AS age_days, CAST(NULL AS INT) AS age_months, CAST(NULL AS INT) AS age_years
UNION ALL
select 5 AS patient_nr, CAST(NULL AS INT) AS age_days, CAST(NULL AS INT) AS age_months, CAST(80 AS INT) AS age_years
), b as (
SELECT ARRAY['D','D','D','M','M','Y','Y','Y'] AS ref_age_cd
, ARRAY[1,4,15,2,7,13,18,199] AS ref_age
, ARRAY[9.1,9.8,5.4,5.5,7.9,5.1,4.8,4.8] AS ref_clow
, ARRAY[27.1,27.8,16.4,15.8,15.9,11.1,10.8,10.8] AS ref_chigh
), refTable AS (
SELECT unnest(ref_age_cd) ref_age_cd
, unnest(ref_age) ref_age
, unnest(ref_clow) ref_clow
, unnest(ref_chigh) ref_chigh
FROM b
), res AS (
SELECT A.*, rt.*, ROW_NUMBER() OVER(PARTITION BY patient_nr ORDER BY ref_age DESC) AS rn
FROM A
LEFT JOIN refTable rt ON (rt.ref_age_cd = 'D' AND a.age_days > rt.ref_age)
OR (rt.ref_age_cd = 'M' AND a.age_months > rt.ref_age)
OR (rt.ref_age_cd = 'Y' AND a.age_years > rt.ref_age)
)
SELECT *
FROM res
WHERE rn = 1
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