更改函数以便它检索数组类型参数会导致错误 : FUNCTION DOES NOT EXIST

Question

我更改了一个函数，使其接收三个参数，而不是仅接收两个。在age--1.2.0.sql文件中，之前设置为:

CREATE FUNCTION ag_catalog.create_vlabel(graph_name name, label_name name)
    RETURNS void
    LANGUAGE c
AS 'MODULE_PATHNAME';

然后我改为:

CREATE FUNCTION ag_catalog.create_vlabel(graph_name name, label_name name, parent_list name[])
    RETURNS void
    LANGUAGE c
AS 'MODULE_PATHNAME';

在此之后，我修改了 label_commands.c 文件中的相同函数，以便它检查第三个参数是否为空。如果不是，它遍历列表，将父标签添加到 List *parent，然后创建继承自父标签的标签。这是我添加此功能的代码块:

    // [...]
    
    // Added these variables:
    
    ArrayType *list_parents;
    Datum *elements_parent_names;
    Name parent_name;
    char *parent_name_str;
    int num_parents;
    
    // [...]
    
    //Create the default label tables
    graph = graph_name->data;
    label = label_name->data;

    rv = get_label_range_var(graph, graph_oid, AG_DEFAULT_LABEL_VERTEX);
    parent = list_make1(rv);

    // checking if user has provided the parent's name list.
    if (!PG_ARGISNULL(2)) {

        // Get the content from the third argument - which is an array.
        list_parents = PG_GETARG_ARRAYTYPE_P(2);
        num_parents = ArrayGetNItems(ARR_NDIM(list_parents), ARR_DIMS(list_parents));
        elements_parent_names = (Datum *) ARR_DATA_PTR(list_parents);
        
        // Check for each parent in the list.
        for (int i = 0; i < num_parents; i++) {
            
            parent_name = DatumGetName(elements_parent_names[i]);
            parent_name_str = NameStr(*parent_name);

            // Check if parent label does not exist
            if (!label_exists(parent_name_str, graph_oid)) {
                ereport(ERROR,
                        (errcode(ERRCODE_UNDEFINED_SCHEMA),
                                errmsg("parent label \"%s\" does not exist.", parent_name_str)));
            }

            rv = get_label_range_var(graph, graph_oid, parent_name->data);

            lappend(parent, rv);
        }
    }

    create_label(graph, label, LABEL_TYPE_VERTEX, parent);

大家可以查看原码here .

在此之后，我尝试像这样调用函数:

--(this works)

SELECT * FROM ag_catalog.create_vlabel('demo', 'Book');
NOTICE:  VLabel "Book" has been created
 create_vlabel 
---------------
 
(1 row)

但是如果我这样调用:

--(I get an error)

SELECT * FROM ag_catalog.create_vlabel('demo', 'Fantasy', ARRAY['Book']);
ERROR:  function ag_catalog.create_vlabel(unknown, unknown, text[]) does not exist
LINE 1: SELECT * FROM ag_catalog.create_vlabel('demo', 'Fantasy', ARRAY...
                      ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

我怎样才能解决这个问题，以便它成功地从传递的数组中获取所有元素？

Answer 1

尝试删除扩展，然后重新创建它。

DROP EXTENSION age CASCADE;
CREATE EXTENSION age;
LOAD age;