Question

我试图创建以下函数，该函数将角色插入表中，获取ID值，然后在“创建表”调用中使用该ID值。

 CREATE FUNCTION data.addtable (sch text, tbl text) RETURNS INTEGER AS $$
  begin
    WITH i AS (
        SELECT nextval('data.customdata_id_seq') AS id
    )
    INSERT INTO "data"."customtables" (id,        
    ownerid,name,internalname,tableinfo)
    SELECT id, 15,tbl, 'tbl_' || id, ('{
   "counter": "2",
   "tablename": "' || sch ||'_tbl_' || id || '",
   "headers": ["ID", "First Name", "Last Name"],
   "columns": [
    {"data": "id"},
   {"data": "field_1"},
   {"data": "field_2"}
   ]
    }')::jsonb 
  FROM  i RETURNING ID;
  EXECUTE 'Create table ' || sch || '.' || 'tbl_'  || id || ' (id serial 
  primary key, field_1 varchar(100), field_2 varchar(100))';
  end;
  $$ LANGUAGE plpgsql;

当我尝试运行它时，出现错误：

    ERROR:  column "id" does not exist
    LINE 1: ...ELECT 'Create table ' || sch || '.' || 'tbl_'  || id || ' 
   (i...
                                                         ^
    QUERY:  SELECT 'Create table ' || sch || '.' || 'tbl_'  || id || ' (id 
    serial primary key, field_1 varchar(100), field_2 varchar(100))'
    CONTEXT:  PL/pgSQL function data.addtable(text,text) line 18 at EXECUTE
    SQL state: 42703

要插入到CustomTables中的查询的第一部分有效，但是如何传递/引用此ID，以便可以在EXECUTE命令中使用它来创建动态表？我还希望它以整数形式返回ID。

更新，我进行了一些更改：试图弄清为什么它不起作用？

   CREATE FUNCTION data.addtable (sch text, tbl text) RETURNS integer AS $$
   DECLARE
    _id data.customtables.id%TYPE;

 BEGIN  
 SELECT nextval('data.customdata_id_seq') AS id into _id;
  INSERT INTO "data"."customtables" (id, 
  ownerid,name,internalname,tableinfo)
  SELECT _id, 15,tbl, 'tbl_' || _id, ('{
 "counter": "2",
  "tablename": "' || sch ||'_tbl_' || _id || '",
  "headers": ["ID", "First Name", "Last Name"],
  "columns": [
   {"data": "id"},
     {"data": "field_1"},
     {"data": "field_2"}
    ]
  }')::jsonb;

 EXECUTE 'Create table ' || sch || '.' || 'tbl_'  || _id ' (id serial 
 primary key, field_1 varchar(100), field_2 varchar(100))';
 return _id;
 END;
 $$ LANGUAGE plpgsql;

由于某种原因，它在top语句中知道_id，但是由于_id在EXECUTE语句中“不存在”而引发错误。为什么？

弄清楚了，只是缺少了||。在_id之后。工作。

Answer 1

您可以将ID返回到变量中，并在串联中使用它。

CREATE FUNCTION data.addtable (sch text,
                               tbl text)
                RETURNS integer
AS
$$
DECLARE
  _id data.customtables.id%TYPE;
BEGIN
  WITH ...
  INSERT INTO ...
         SELECT ...
         RETURNING id
                   INTO _id;
  EXECUTE 'CREATE TABLE ' || sch || '.' || 'tbl_'  || _id || ' (id serial primary key, field_1 varchar(100), field_2 varchar(100))';
END;
$$
LANGUAGE plpgsql;

postgres，如何在创建表的函数中引用插入ID？

1 个答案: