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

noobie 发表于 Dev

Noobie

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：

（3706，“ [42000] [Teradata] [ODBC Teradata驱动程序] Teradata DatabaseSyntax错误：预期介于'（'和'（'。”之间）

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python文件中将其运行为：

df_teradata = pd.read_sql(td_query, connect)

哪里connect是td.UdaExec对象，上面的代码是其他简单的查询，如工作的罚款select * from tdwm.student_2。

我也尝试过最小化版本的同一查询，我得到相同的错误。

这是我使用的代码td_query：

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)

黑胡子

我遇到了类似的问题。

您的查询存在的问题是它包含hash_md5未知的函数，这就是teradata python module错误的原因。

解：

在该函数之前添加数据库名称（就像在表名称之前添加数据库名称一样tdwm.student_2）。因此，您的新查询将是：

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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