Question

我要创建此函数，但变量view_size被视为列。

我收到错误消息column view_size don't exists.

为什么？

如果我改变了上下文，它就可以了（例如：只进行查询，被视为变量）。

CREATE OR REPLACE FUNCTION create_view(view_size INTEGER) RETURNS VOID  
AS $$
BEGIN
    CREATE VIEW token_relation
    AS
    SELECT * FROM textblockhastoken     
    ORDER BY textblockid, sentence, position
    LIMIT view_size;
END
$$
LANGUAGE plpgsql;

Answer 1

请改为尝试：

CREATE OR REPLACE FUNCTION create_view(view_size INTEGER) RETURNS VOID  
AS $$
BEGIN
    EXECUTE 'CREATE VIEW token_relation 
    AS 
    SELECT * FROM textblockhastoken 
    ORDER BY textblockid, sentence, position 
    LIMIT ' || view_size;
END
$$
LANGUAGE plpgsql;

为什么变量被视为列？

1 个答案: