我希望能够在postgres(9.5)中部分地进行upsert,但是当不满足所有约束时(例如not null约束),似乎部分upsert失败了
以下是方案和错误的示例
CREATE TABLE jobs (
id integer PRIMARY KEY,employee_name TEXT NOT NULL,address TEXT NOT NULL,phone_number TEXT
);
CREATE OR REPLACE FUNCTION upsert_job(job JSONB)
RETURNS VOID AS $$
BEGIN
INSERT INTO jobs AS origin VALUES(
(job->>'id')::INTEGER,job->>'employee_name'::TEXT,job->>'address'::TEXT,job->>'phone_number'::TEXT
) ON CONFLICT (id) DO UPDATE SET
employee_name = COALESCE(EXCLUDED.employee_name,origin.employee_name),address = COALESCE(EXCLUDED.address,origin.address),phone_number = COALESCE(EXCLUDED.phone_number,origin.phone_number);
END;
$$LANGUAGE PLPGsql SECURITY DEFINER;
--Full insert (OK)
SELECT upsert_job('{"id" : 1,"employee_name" : "AAA","address" : "City,x street no.y","phone_number" : "123456789"}'::jsonb);
--Partial update that fulfills constraint (Ok)
SELECT upsert_job('{"id" : 1,"employee_name" : "BBB",x street no.y"}'::jsonb);
--Partial update that doesn't fulfill constraint (FAILS)
SELECT upsert_job('{"id" : 1,"phone_number" : "12345"}'::jsonb);
--ERROR: null value in column "employee_name" violates not-null constraint
--DETAIL: Failing row contains (1,null,12345).
我该如何解决这个问题呢？
解决方法
再想一想,如果id还没有存在怎么办？你不能只插入一个电话号码,因为它没有名字/地址,但这正是你告诉它要做的.因此约束变得疯狂并且失败,因为upsert尝试先插入然后在插入失败时更新.但是你的插入没有通过约束检查以查看它是否已经存在.
如果你想要部分,你可以做的是告诉它如何处理违反约束的部分.像这样的东西(这是不完整的,不处理所有部分数据场景)：
CREATE OR REPLACE FUNCTION upsert_job(job JSONB)
RETURNS VOID AS $$
BEGIN
IF (job->>'phone_number' IS NOT NULL
AND job->>'employee_name' IS NOT NULL
AND job->>'address' IS NOT NULL) THEN
INSERT INTO jobs AS origin VALUES(
(job->>'id')::INTEGER,job->>'phone_number'::TEXT
) ON CONFLICT (id) DO UPDATE SET
employee_name = COALESCE(EXCLUDED.employee_name,origin.phone_number);
ELSIF (job->>'phone_number' IS NOT NULL AND (job->>'employee_name' IS NULL AND job->>'address' IS NULL)) THEN
UPDATE jobs SET phone_number=job->>'phone_number'::TEXT
WHERE id=(job->>'id')::INTEGER;
END IF;
END;
$$LANGUAGE PLPGsql SECURITY DEFINER;
