查询在查询浏览器中工作正常，但在python代码中却无法正常工作 [英] Query is working fine in query browser but not in python code

问题描述

我有一个Teradata sql查询，该查询在Teradata Studio Express的查询浏览器中运行良好，但是当我尝试在python代码中运行相同的查询时，出现以下错误:

I have a teradata sql query which is working fine in Teradata Studio Express's query browser but when I tried to run the same query in my python code I am getting following error:

(3706，"[42000] [Teradata] [ODBC Teradata驱动程序] Teradata DatabaseSyntax错误:预期在'('和之间 '('.)

(3706, "[42000] [Teradata][ODBC Teradata Driver]Teradata DatabaseSyntax error: expected something between '(' and '('.")

我的查询:

td_query = """select 
hash_md5((XMLAGG(TRIM(h_age) ORDER BY h_age ASC) (VARCHAR(100))) )hash_age,
hash_md5((XMLAGG(TRIM(h_marks) ORDER BY h_age ASC )(VARCHAR(100)))) hash_marks,
hash_md5((XMLAGG(TRIM(h_id) ORDER BY h_age ASC )(VARCHAR(100)))) hash_id,
hash_md5((XMLAGG(TRIM(h_score) ORDER BY h_age ASC )(VARCHAR(100))))hash_score,
hash_md5((XMLAGG(TRIM(h_name) ORDER BY h_age ASC )(VARCHAR(100))))hash_name,
hash_md5((XMLAGG(TRIM(h_entry) ORDER BY h_entry ASC )(VARCHAR(100))))hash_entry,
SUM(Aggrownum) sum_val,
COUNT(Aggrownum) count_val,
sum_val/count_val row_num
from 
(
Select 
hash_md5(CAST(age AS VARCHAR(100)))h_age ,
hash_md5(CAST(marks AS VARCHAR(100)))h_marks,
hash_md5(CAST(id AS VARCHAR(100)))h_id,
hash_md5(CAST(score AS VARCHAR(100)))h_score,
hash_md5(CAST(f_name AS VARCHAR(100)))h_name,
hash_md5(CAST(entry AS FORMAT 'yyyy-mm-ddbhh:mi:ss') (char (20)))h_entry,
row_number() over (partition by dob order by  age asc) rno,round(rno/500.0) Aggrownum
from tdwm.student_2
) A group by Aggrownum ORDER BY row_num;
"""

并在运行它的python文件中:

and in python file running it as:

df_teradata = pd.read_sql(td_query, connect)            

其中connect是td.UdaExec对象，并且上面的代码对于其他更简单的查询(例如select * from tdwm.student_2)也可以正常工作.

Where connect is the td.UdaExec object and above code is working fine for other simpler queries such as select * from tdwm.student_2.

我还尝试了最小化版本的同一查询，但出现了相同的错误.

I also tried minimized version of the same query I am getting the same error.

这是我使用td_query的代码:

import pandas as pd
import teradata as td

td_host, td_username, td_passwd, td_dbname = '10.20.181.55', 'dbac', 'dbac', 'tdwm'

udaExec = td.UdaExec(appName="test", version="1.0", logConsole=False)
with udaExec.connect(method="odbc",system=td_host, username=td_username, port=1025,
                            password=td_passwd, driver="Teradata Database ODBC Driver 16.20") as connect:
    df_teradata = pd.read_sql(td_query, connect)

推荐答案

我遇到了类似的问题.

查询的问题是它包含teradata python module未知的hash_md5函数，这就是错误的原因.

The issue with your query is that it contains hash_md5 function which is unknown to teradata python module, that's why the error.

解决方案:

在该函数之前添加数据库名称(就像您在表名称tdwm.student_2之前所做的一样).因此，您的新查询将是:

Add database name before that function (like you have done before table name tdwm.student_2). So your new query will be:

select 
 tdwm.hash_md5((XMLAGG(TRIM(h_age) ORDER BY h_age ASC) (VARCHAR(100))) )hash_age,
 tdwm.hash_md5((XMLAGG(TRIM(h_marks) ORDER BY h_age ASC )(VARCHAR(100)))) hash_marks,
 tdwm.hash_md5((XMLAGG(TRIM(h_id) ORDER BY h_age ASC )(VARCHAR(100)))) hash_id,
 tdwm.hash_md5((XMLAGG(TRIM(h_score) ORDER BY h_age ASC )(VARCHAR(100))))hash_score,
 tdwm.hash_md5((XMLAGG(TRIM(h_name) ORDER BY h_age ASC )(VARCHAR(100))))hash_name,
 tdwm.hash_md5((XMLAGG(TRIM(h_entry) ORDER BY h_entry ASC )(VARCHAR(100))))hash_entry,
 SUM(Aggrownum) sum_val,
 COUNT(Aggrownum) count_val,
 sum_val/count_val row_num
 from 
 (
 Select 
  tdwm.hash_md5(CAST(age AS VARCHAR(100)))h_age ,
  tdwm.hash_md5(CAST(marks AS VARCHAR(100)))h_marks,
  tdwm.hash_md5(CAST(id AS VARCHAR(100)))h_id,
  tdwm.hash_md5(CAST(score AS VARCHAR(100)))h_score,
  tdwm.hash_md5(CAST(f_name AS VARCHAR(100)))h_name,
  tdwm.hash_md5(CAST(entry AS FORMAT 'yyyy-mm-ddbhh:mi:ss') (char (20)))h_entry,
 row_number() over (partition by dob order by  age asc) rno,round(rno/500.0) Aggrownum
 from tdwm.student_2
 ) A group by Aggrownum ORDER BY row_num;

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