pg12新特性-copy_from支持where條件過濾

官方文檔描述

E.5. Release 12 E.5.3. Changes E.5.3.3. Utility Commands

Add a WHERE clause to COPY FROM to control which rows are accepted (Surafel Temesgen)

This provides a simple way to filter incoming data.

refRelease 12

示例

創建測試表

CREATE TABLE test_copy(id int ,name varchar,insert_time timestamp(0) without time zone default clock_timestamp());
INSERT INTO  test_copy(id,name)  select n,n||'_test'  from generate_series(1,1000) n;  
ALTER TABLE test_copy ADD PRIMARY KEY (id);

導出表數據

COPY (SELECT * FROM test_copy WHERE id < 101) TO '/tmp/test_copy_100';

創建目標表

CREATE TABLE test_copy2 (like test_copy);

導入數據（使用where限定）

COPY test_copy2 from '/tmp/test_copy_100' where id<10;

此時數據依據where條件進行了過濾，將過濾後的數據導入到數據庫中。