postgresql - 动态查询postgres

Question

我是 postgres 的新手，正在运行以下动态查询

EXECUTE 'Select * from products';

我收到以下回复。

ERROR: syntax error at or near "'Select * from products'" 
LINE 1: EXECUTE 'Select * from products';

我知道这是我缺少的基本内容

Answer 1

有EXECUTE plpgsql 的语句，它会执行您正在尝试执行的操作 - 执行 SQL 查询字符串。您标记了 dynamic ，所以这可能就是您要找的。

仅适用于 plpgsql 函数或 DO 语句(匿名代码块)。 The distinction between EXECUTE and SQL-EXECUTE made clear in the fine manual :

Note: The PL/pgSQL EXECUTE statement is not related to the EXECUTE SQL statement supported by the PostgreSQL server. The server's EXECUTE statement cannot be used directly within PL/pgSQL functions (and is not needed).

如果您想从动态 SELECT 返回值查询如您的示例所示，您需要创建一个函数。 DO语句总是返回 void . More about returning values from a function in the very fine manual.