Pl/pgSQL anonymous code block fails on [42601] ERROR: query has no destination for result data

Question

假设下面的简化 DO 匿名代码块位于我在应用程序启动时导入的 sql 脚本中：

-- table definitions omitted
-- assume I want to use anonymous code because of looping

DO
$$
DECLARE
    parentId BIGINT;
    inputArray VARCHAR[][] := ARRAY [['a', 'A'], ['b', 'B'], ['c', 'C']];
    input VARCHAR[];
BEGIN
    FOREACH input SLICE 1 IN ARRAY inputArray
    LOOP
        INSERT INTO myParent (name) VALUES (input[1]) RETURNING id AS parentId;
        INSERT INTO myTable (id, name) VALUES (parentId, input[2]);
    END LOOP;
END;
$$ LANGUAGE plpgsql;

导入并执行脚本后，由于以下错误而失败：

[42601] ERROR: query has no destination for result data 
Where: PL/pgSQL function inline_code_block line 13 at SQL statement

我在 https://www.postgresql.org/docs/current/sql-do.html 阅读了 PostgreSQL DO 语句文档，它说：

DO executes an anonymous code block, or in other words a transient anonymous function in a procedural language.

The code block is treated as though it were the body of a function with no parameters, returning void. It is parsed and executed a single time.

我希望 DO 匿名代码中的 INSERT 语句能够顺利执行并继续。如前所述，它是一个没有参数并返回 void 的函数。为什么它是预期的结果数据和存储它们的东西？

Answer 1

我发现 RETURNING 导致了问题并混淆了整个块的 return 类型。 AS 应该替换为 INTO 然后块开始完美地工作。

错误：

INSERT INTO myParent (name) VALUES (input[1]) RETURNING id AS parentId;

正确：

INSERT INTO myParent (name) VALUES (input[1]) RETURNING id INTO parentId;

Pl/pgSQL anonymous code block fails on [42601] ERROR: query has no destination for result data

Pl/pgSQL anonymous code block fails on [42601] ERROR: query has no destination for result data

sql

postgresql

anonymous-function

plpgsql