更改函数以检索数组类型参数会导致错误：函数不存在

huangapple
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英文:

Changing function so that it retrieves an array type argument causes ERROR: FUNCTION DOES NOT EXIST

问题

I changed a function so that it receives three arguments instead of only two. In the age--1.2.0.sql file, it was set before as:

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

And then I changed to:

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

After this, I modified the same function in label_commands.c file so that it checks if the third argument is null. If it is not, it iterates through the list, adds the parent labels to a List *parent, and then creates the label inheriting from the parent labels. Here is the block of code where I add this functionality:

  1.     // [...]
  3.     // Added these variables:
  5.     ArrayType *list_parents;
  6.     Datum *elements_parent_names;
  7.     Name parent_name;
  8.     char *parent_name_str;
  9.     int num_parents;
  11.     // [...]
  13.     //Create the default label tables
  14.     graph = graph_name->data;
  15.     label = label_name->data;
  17.     rv = get_label_range_var(graph, graph_oid, AG_DEFAULT_LABEL_VERTEX);
  18.     parent = list_make1(rv);
  20.     // checking if user has provided the parent's name list.
  21.     if (!PG_ARGISNULL(2)) {
  23.         // Get the content from the third argument - which is an array.
  24.         list_parents = PG_GETARG_ARRAYTYPE_P(2);
  25.         num_parents = ArrayGetNItems(ARR_NDIM(list_parents), ARR_DIMS(list_parents));
  26.         elements_parent_names = (Datum *) ARR_DATA_PTR(list_parents);
  28.         // Check for each parent in the list.
  29.         for (int i = 0; i < num_parents; i++) {
  31.             parent_name = DatumGetName(elements_parent_names[i]);
  32.             parent_name_str = NameStr(*parent_name);
  34.             // Check if parent label does not exist
  35.             if (!label_exists(parent_name_str, graph_oid)) {
  36.                 ereport(ERROR,
  37.                         (errcode(ERRCODE_UNDEFINED_SCHEMA),
  38.                                 errmsg("parent label \"%s\" does not exist.", parent_name_str)));
  39.             }
  41.             rv = get_label_range_var(graph, graph_oid, parent_name->data);
  43.             lappend(parent, rv);
  44.         }
  45.     }
  47.     create_label(graph, label, LABEL_TYPE_VERTEX, parent);

You guys can view the original code here.

After this, I tried calling the function like this:

  1. --(this works)
  3. SELECT * FROM ag_catalog.create_vlabel('demo', 'Book');
  4. NOTICE:  VLabel "Book" has been created
  5.  create_vlabel 
  6. ---------------
  8. (1 row)

But then if I call like this:

  1. --(I get an error)
  3. SELECT * FROM ag_catalog.create_vlabel('demo', 'Fantasy', ARRAY['Book']);
  4. ERROR:  function ag_catalog.create_vlabel(unknown, unknown, text[]) does not exist
  5. LINE 1: SELECT * FROM ag_catalog.create_vlabel('demo', 'Fantasy', ARRAY...
  6.                       ^
  7. HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

How can I fix this so that it successfully gets all the elements from the passed array?

英文:

I changed a function so that it receives three arguments instead of only two. In the age--1.2.0.sql file, it was set before as:

  1. CREATE FUNCTION ag_catalog.create_vlabel(graph_name name, label_name name)
  2.     RETURNS void
  3.     LANGUAGE c
  4. AS &#39;MODULE_PATHNAME&#39;;

And then I changed to:

  1. CREATE FUNCTION ag_catalog.create_vlabel(graph_name name, label_name name, parent_list name[])
  2.     RETURNS void
  3.     LANGUAGE c
  4. AS &#39;MODULE_PATHNAME&#39;;

After this, I modified the same function in label_commands.c file so that it checks if the third argument is null. If it is not, it iterates through the list, adds the parent labels to a List *parent, and then creates the label inheriting from the parent labels. Here is the block of code where I add this functionality:

  1.     // [...]
  2.     
  3.     // Added these variables:
  4.     
  5.     ArrayType *list_parents;
  6.     Datum *elements_parent_names;
  7.     Name parent_name;
  8.     char *parent_name_str;
  9.     int num_parents;
  10.     
  11.     // [...]
  12.     
  13.     //Create the default label tables
  14.     graph = graph_name-&gt;data;
  15.     label = label_name-&gt;data;
  17.     rv = get_label_range_var(graph, graph_oid, AG_DEFAULT_LABEL_VERTEX);
  18.     parent = list_make1(rv);
  20.     // checking if user has provided the parent&#39;s name list.
  21.     if (!PG_ARGISNULL(2)) {
  23.         // Get the content from the third argument - which is an array.
  24.         list_parents = PG_GETARG_ARRAYTYPE_P(2);
  25.         num_parents = ArrayGetNItems(ARR_NDIM(list_parents), ARR_DIMS(list_parents));
  26.         elements_parent_names = (Datum *) ARR_DATA_PTR(list_parents);
  27.         
  28.         // Check for each parent in the list.
  29.         for (int i = 0; i &lt; num_parents; i++) {
  30.             
  31.             parent_name = DatumGetName(elements_parent_names[i]);
  32.             parent_name_str = NameStr(*parent_name);
  34.             // Check if parent label does not exist
  35.             if (!label_exists(parent_name_str, graph_oid)) {
  36.                 ereport(ERROR,
  37.                         (errcode(ERRCODE_UNDEFINED_SCHEMA),
  38.                                 errmsg(&quot;parent label \&quot;%s\&quot; does not exist.&quot;, parent_name_str)));
  39.             }
  41.             rv = get_label_range_var(graph, graph_oid, parent_name-&gt;data);
  43.             lappend(parent, rv);
  44.         }
  45.     }
  47.     create_label(graph, label, LABEL_TYPE_VERTEX, parent);

You guys can view the original code here.

After this, I tried calling the function like this:

  1. --(this works)
  3. SELECT * FROM ag_catalog.create_vlabel(&#39;demo&#39;, &#39;Book&#39;);
  4. NOTICE:  VLabel &quot;Book&quot; has been created
  5.  create_vlabel 
  6. ---------------
  7.  
  8. (1 row)

But then if I call like this:

  1. --(I get an error)
  3. SELECT * FROM ag_catalog.create_vlabel(&#39;demo&#39;, &#39;Fantasy&#39;, ARRAY[&#39;Book&#39;]);
  4. ERROR:  function ag_catalog.create_vlabel(unknown, unknown, text[]) does not exist
  5. LINE 1: SELECT * FROM ag_catalog.create_vlabel(&#39;demo&#39;, &#39;Fantasy&#39;, ARRAY...
  6.                       ^
  7. HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

How can I fix this so that it successfully gets all the elements from the passed array?

答案1

得分: 3

尝试删除扩展，然后重新创建它。

  1. DROP EXTENSION age CASCADE;
  2. CREATE EXTENSION age;
  3. LOAD age;
英文:

Try dropping the extension, and then re-creating it.

  1. DROP EXTENSION age CASCADE;
  2. CREATE EXTENSION age;
  3. LOAD age;

答案2

得分: 2

这是一个好主意，如Rafsun所提到的，删除扩展名是一个好主意。如果即使这样也不起作用，我注意到您在list_parents上使用了ArrayType。我观察到每当源代码中使用ArrayType时，都使用了deconstruct_array()。也许这就是它无法访问parent_name和parent_name_str内存的原因。我们可能需要将数组处理成其他形式，然后再使用它们。

有关如何使用deconstruct_array的详细信息，请参考这张图片：

更改函数以检索数组类型参数会导致错误：函数不存在

英文:

It's a good thing to drop the extension as mentioned by Rafsun. If even that doesn't work, I see that you've used ArrayType for list_parents. I've observed whenever ArrayType was used in source code, deconstruct_array() has been used. Maybe that's the reason it's unable to access the memory of parent_name and parent_name_str. We might have to process the array into something and then use those.

Refer this image for details on how to use deconstruct_array

更改函数以检索数组类型参数会导致错误：函数不存在

答案3

得分: 1

你应该再次在age文件夹中运行make命令：

  1. sudo make PG_CONFIG=/path/to/postgres/bin/pg_config install

然后删除扩展，并按Rafsun的指示重新创建它。

然后，你应该添加以下代码：

  1. if (!PG_ARGISNULL(2))
  2. {
  3.     // 检查第三个参数是否为字符串
  4.     ArrayType *keys = PG_GETARG_ARRAYTYPE_P(2);
  5.     int elem_count = 0;
  7.     Datum *parents_datums;
  8.     bool *parent_nulls;
  9.     int i;
  11.     // 获取数组中的元素和父元素数据
  12.     deconstruct_array(keys, NAMEOID, 63, false, 'i', &parents_datums, &parent_nulls, &elem_count);
  14.     for (i = 0; i < elem_count; i++) {
  15.         elog(NOTICE, "第 %d 个索引处的值：%s", i, DatumGetCString(parents_datums[i]));
  16.     }
  18.     // 打印第一个索引处的值
  19.     elog(NOTICE, "第一个索引处的值：%d", keys[0].elemtype);
  21.     // 打印数组中的元素数量
  22.     elog(NOTICE, "数组中的元素数量：%d", elem_count);
  23. }
英文:

You should run the make command in age folder again:

  1. sudo make PG_CONFIG=/path/to/postgres/bin/pg_config install

Then drop the extension, and re-create it as told by Rafsun.

Then you should add the following code:

  1. if (!PG_ARGISNULL(2))
  2. {
  3.     //check if the third argument is a string
  4.     ArrayType  *keys = PG_GETARG_ARRAYTYPE_P(2);
  5.     int elem_count=0;
  7.     Datum *parents_datums;
  8.     bool *parent_nulls;
  9.     int i;
  11.     
  12.     // elem_count = ArrayGetNItems(ARR_NDIM(keys), ARR_DIMS(keys));
  14.     //get the elements in the array and parents data
  15.     deconstruct_array(keys, NAMEOID, 63, false, &#39;i&#39;, &amp;parents_datums, &amp;parent_nulls, &amp;elem_count);
  17.     for (i=0;i&lt;elem_count;i++){
  18.         elog(NOTICE, &quot;Value at the %d index: %s&quot;, i, DatumGetCString(parents_datums[i]));
  19.     }
  21.     //print the value at the first index
  22.     elog(NOTICE, &quot;Value at the first index: %d&quot;, keys[0].elemtype);
  25.     //print the number  of elements in the array
  26.     elog(NOTICE, &quot;Number of elements in the array: %d&quot;, elem_count);
  28. }

huangapple
  • 本文由 发表于 2023年2月10日 04:21:56
  • 转载请务必保留本文链接：https://go.coder-hub.com/75404035.html
  • apache-age
  • c
  • postgresql
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