没有匹配的函数，可能需要添加显式类型转换

Question

代码中的以下语句让我遇到了一个错误：

cur.execute("
   update %s as A
   set fm = foo.fm
   from (
      select src_id as id, agg_bit_or(fm) as fm
      from %s, %s where dst_id = id
      group by src_id) as foo
   where A.id = foo.id" %(tmp_table, edge_table, vertex_table))

agg_bit_or() 是一个在Postgres中定义的用户自定义聚合函数：

CREATE AGGREGATE agg_bit_or(bit[])
(
    sfunc = bit_or,
    stype = bit[]   
);

错误信息是：

File "radius.py", line 47, in update_bitstring
cur.execute("update %s as A set fm = foo.fm from (select src_id as id, agg_b
it_or(fm)  from %s, %s where dst_id = id group by src_id) as foo where A.id = fo
o.id" %(tmp_table, edge_table, vertex_table))

psycopg2.ProgrammingError: function agg_bit_or(integer[]) does not exist
LINE 1: ...v as A set fm = foo.fm from (select src_id as id, agg_bit_or...
                                                         ^
HINT:  No function matches the given name and argument types. You might need to
add explicit type casts.

Answer 1

错误信息显示：

psycopg2.ProgrammingError: 函数 agg_bit_or(integer[]) 不存在

而你的聚合函数是这样定义的：

CREATE AGGREGATE agg_bit_or(bit[])

我强调的部分。你需要确保使用的类型是兼容的。