Question

我需要以某种方式从json转换为int。我做了这个功能。：

CREATE OR REPLACE FUNCTION json2int(p_json json)
  RETURNS integer AS
$BODY$DECLARE
  v_json json;
  --v_char character varying;
  v_int integer;
BEGIN
  SELECT p_json->'additionalData'->'id' INTO v_json;
  --SELECT CAST(v_json as character varying) INTO v_char;
  SELECT CAST(v_json as integer) INTO v_int;
  RETURN v_int;
END;$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION json2int(json)
  OWNER TO postgres;

我尝试从json转换为int，但这不起作用。然后我尝试从json转换为变为int的字符，这也没有用。所以我补充道：

CREATE CAST (json AS integer) WITH INOUT as implicit;

现在当我运行我的功能时：

SELECT json2int('{"additionalData":{"id":"4","userType":"viewer"},"type":"wall"}');

我收到此错误：

ERROR:  invalid input syntax for integer: ""4""
CONTEXT:  SQL statement "SELECT CAST(v_json as integer)"
PL/pgSQL function json2int(json) line 8 at SQL statement

有人可以帮忙吗？

Answer 1

正如评论中所暗示的，使用->>将文本转换为int：

SELECT (p_json -> 'additionalData' ->> 'id')::int INTO v_int;

从json转到int不工作？

1 个答案: