cypher函数语法如下所示：

SELECT * FROM cypher('graph_name', $$ 
/* Cypher Query Here */ 
$$) AS (result1 agtype, result2 agtype);

因此，有必要将图形的名称作为第一个参数传递，并将查询作为第二个参数传递（注意，查询的开头和结尾必须有两个美元符号）。如果未传递这些参数，则会发生错误，因为函数将无法标识其正在处理的列和名称空间。以下是一些错误示例：

-- Inserting nothing
SELECT * FROM cypher() as (a agtype);
server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

-- Not inserting the double dollar signs
SELECT * FROM cypher('graph_name') as (a agtype);
server closed the connection unexpectedly
    This probably means the server terminated abnormally
    before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.                ^

-- Not passing the query correctly
SELECT * FROM cypher('graph_name', $$$$) as (a agtype);
ERROR:  syntax error at end of input
LINE 1: SELECT * FROM cypher('graph_name', $$$$) as (a agtype);

documentation还指出，我们需要考虑两件事：

• 如果密码查询不返回结果，则仍然需要定义记录定义。
• 参数Map只能与预准备语句一起使用。否则将引发错误。

第一点意味着，如果查询没有返回结果（例如，试图返回不属于顶点或边的属性），则在返回查询时仍然需要显示表结构，即使它是空的。