我想在Postgres函数中传递一个表名作为参数.我试过这段代码:
CREATE OR REPLACE FUNCTION some_f(param character varying) RETURNS integer
AS $$
BEGIN
IF EXISTS (select * from quote_ident($1) where quote_ident($1).id=1) THEN
return 1;
END IF;
return 0;
END;
$$ LANGUAGE plpgsql;
select some_f('table_name');
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我得到了这个:
ERROR: syntax error at or near "."
LINE 4: ...elect * from quote_ident($1) where quote_ident($1).id=1)...
^
********** Error **********
ERROR: syntax error at or near "."
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以下是更改为此时出现的错误select * from quote_ident($1) tab where tab.id=1:
ERROR: column tab.id does not exist
LINE 1: ...T EXISTS …Run Code Online (Sandbox Code Playgroud) CREATE OR REPLACE FUNCTION getParentLtree(parent_id bigint, tbl_name varchar)
RETURNS ltree AS
$BODY$
DECLARE
parent_ltree ltree;
BEGIN
-- This works fine:
-- select into parent_ltree l_tree from tbl1 where id = parent_id;
EXECUTE format('select into parent_ltree l_tree from %I
where id = %I', tbl_name,parent_id);
RETURN parent_ltree;
END;
$BODY$ LANGUAGE plpgsql;
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上述功能有2个问题:
parent_id是integer,但它会被替换引号?int变量的正确格式说明符是什么?select into不起作用EXECUTE?如何使上面的注释查询使用表名传递?