如何使用COMPARISON_TYPE returnType和布尔输入调用cx_Oracle中的函数？

Question

我正在尝试从DBMS_COMPARISON package调用COMPARE function

我首先通过以下方式创建比较：

import cx_Oracle

host = host
service_name = service_name
port = port
password = password
username = username


dsn = cx_Oracle.makedsn( host, port,
                         service_name=service_name )
db = cx_Oracle.connect(username, password, dsn )

keyword_parameters = {
        'comparison_name':'my_comparison',
        'schema_name':'my_schema',      
        'object_name':'table_name',
        'dblink_name':'db_link'
}
cur.callproc('DBMS_COMPARISON.CREATE_COMPARISON', keywordParameters = keyword_parameters)

现在我想调用函数DBMS_COMPARISON.COMPARE

DBMS_COMPARISON.COMPARE(
   comparison_name  IN   VARCHAR2,
   scan_info        OUT  COMPARISON_TYPE,
   min_value        IN   VARCHAR2   DEFAULT NULL,
   max_value        IN   VARCHAR2   DEFAULT NULL,
   perform_row_dif  IN   BOOLEAN    DEFAULT FALSE)
RETURN BOOLEAN;

我试过了

cur.callfunc('DBMS_COMPARISON.COMPARE', int,
             keywordParameters={'comparison_name':'my_comparison', 'scan_info':cur.var(int), 'perform_row_dif':'TRUE'})

或者是某种变种。我很难理解如何设置在调用函数中指定的returnType，以及如何为DBMS_COMPARISON.COMPARE函数调用设置所需的布尔值

Answer 1

这里有一个简单的例子，无论如何，它对我来说是有效的！关键是将"bool“类型传递给cursor.callfunc()调用。

create function IsNumber (a_Value varchar2) return boolean is
    t_Value number;
begin
    begin
        t_Value := to_number(a_Value);
        return true;
    exception
    when others then
        return false;
    end;
end;
/

对应的Python代码如下：

print(cursor.callfunc("IsNumber", bool, ("5",)))
print(cursor.callfunc("IsNumber", bool, ("Fred",)))

这将输出值

真假