使用CSV数据从Postgres复制 [英] Postgres Copy from Variable with CSV data
问题描述
我知道您可以从文件运行这样的复制命令:
I know you can run a copy command like this from a file:
"COPY zip_codes FROM '/path/to/csv/ZIP_CODES.txt' DELIMITER ',' CSV;"
我想从ruby变量中复制csv数据,所以我可以这样做
I'd like to copy csv data from a ruby variable so I can do like so
"COPY zip_codes FROM '#{csv_data}' DELIMITER ',' CSV;"
推荐答案
SQL COPY
命令。 COPY
仅从文件或 STDIN 复制。
That's not possible with the SQL COPY
command. COPY
only copies from a file or STDIN.
您可以将变量的内容写入文件,也可以通过STDIN将其传递。仅适用于几行以上。
You can either write the content of the variable to a file or pipe it via STDIN. Only makes sense for more than a couple of rows.
我想我在更新之前误解了您的问题,您可能不知道不需要:
I think I misunderstood your question before the update, you probably don't need this:
文件路径无法像其他数据项一样交换,因此您不能使用准备好的语句。在执行或诉诸动态SQL之前,先通过服务器端函数构建 whole 语句,
The file path can not be exchanged like other data items, and you can't use a prepared statement for that. Build the whole statement before executing or resort to dynamic SQL with a server-side function like:
CREATE OR REPLACE FUNCTION f_cp(_file text)
RETURNS void AS
$BODY$
BEGIN
EXECUTE format($$COPY zip_codes FROM %L DELIMITER ',' CSV$$, $1);
END
$BODY$
LANGUAGE plpgsql;
致电:
SELECT f_cp('/var/lib/postgres/sync/myfile.csv')
format()
需要Postgres 9.1或更高版本。
format()
requires Postgres 9.1 or later.
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