Postgresql 10：如何将 4 个现有列移动到数组列

Question

我有以下 table 客户：

 Table "public.client"
       Column        |  Type   | Collation | Nullable |           Default            
---------------------+---------+-----------+----------+------------------------------
 clientid            | integer |           | not null | generated always as identity
 account_name        | text    |           | not null | 
 last_name           | text    |           |          | 
 first_name          | text    |           |          | 
 address             | text    |           | not null | 
 suburbid            | integer |           |          | 
 cityid              | integer |           |          | 
 post_code           | integer |           | not null | 
 business_phone      | text    |           |          | 
 home_phone          | text    |           |          | 
 mobile_phone        | text    |           |          | 
 alternative_phone   | text    |           |          | 
 email               | text    |           |          | 
 quote_detailsid     | integer |           |          | 
 invoice_typeid      | integer |           |          | 
 payment_typeid      | integer |           |          | 
 job_typeid          | integer |           |          | 
 communicationid     | integer |           |          | 
 accessid            | integer |           |          | 
 difficulty_levelid  | integer |           |          | 
 current_lawn_price  | numeric |           |          | 
 square_meters       | numeric |           |          | 
 note                | text    |           |          | 
 client_statusid     | integer |           |          | 
 reason_for_statusid | integer |           |          | 
Indexes:
    "client_pkey" PRIMARY KEY, btree (clientid)
    "account_name_check" UNIQUE CONSTRAINT, btree (account_name)
Foreign-key constraints:
    "client_accessid_fkey" FOREIGN KEY (accessid) REFERENCES access(accessid)
    "client_cityid_fkey" FOREIGN KEY (cityid) REFERENCES city(cityid)
    "client_client_statusid_fkey" FOREIGN KEY (client_statusid) REFERENCES client_status(client_statusid)
    "client_communicationid_fkey" FOREIGN KEY (communicationid) REFERENCES communication(communicationid)
    "client_difficulty_levelid_fkey" FOREIGN KEY (difficulty_levelid) REFERENCES difficulty_level(difficulty_levelid)
    "client_invoice_typeid_fkey" FOREIGN KEY (invoice_typeid) REFERENCES invoice_type(invoice_typeid)
    "client_job_typeid_fkey" FOREIGN KEY (job_typeid) REFERENCES job_type(job_typeid)
    "client_payment_typeid_fkey" FOREIGN KEY (payment_typeid) REFERENCES payment_type(payment_typeid)
    "client_quote_detailsid_fkey" FOREIGN KEY (quote_detailsid) REFERENCES quote_details(quote_detailsid)
    "client_reason_for_statusid_fkey" FOREIGN KEY (reason_for_statusid) REFERENCES reason_for_status(reason_for_statusid)
    "client_suburbid_fkey" FOREIGN KEY (suburbid) REFERENCES suburb(suburbid)
Referenced by:
    TABLE "work" CONSTRAINT "work_clientid_fkey" FOREIGN KEY (clientid) REFERENCES client(clientid)

我想将所有 phone 列（business_phone、home_phone、mobile_phone、alternative_phone）作为数组移动到名为 phone_numbers 并去掉四个 phone_columns。知道如何在不丢失任何记录的情况下安全地执行此操作吗？

Answer 1

添加数组列。

ALTER TABLE client
ADD COLUMN phone_numbers text[];

然后使用更新命令根据其他四个设置数组列的值。

UPDATE client
SET phone_numbers = [business_phone,home_phone,mobile_phone,alternate_phone]; -- test and modify if needed

您可以重复此更新多次，直到正确为止。然后你可以安全地删除四个旧列。

ALTER TABLE client
DROP COLUMN business_phone
DROP COLUMN home_phone
DROP COLUMN mobile_phone
DROP COLUMN alternate_phone;

Postgresql 10：如何将 4 个现有列移动到数组列

Postgresql 10: How to move 4 existing columns to an array column

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