使用Psycopg2将数据从S3复制到AWS Redshift时出错

Question

While executing a COPY command utilizing psycopg2, I receive the error:

psycopg2.ProgrammingError: unterminated quoted string at or near "'"
LINE 12:    NULL as '

Here is my origianl query:

"""copy dcm_floodlight_raw_abg_stg (COLUMN_NAMES)
from 'S3_BUCKET_PATH'
CREDENTIALS 'aws_access_key_id=KEY;aws_secret_access_key=SECRET'
gzip
DELIMITER '\t'
DATEFORMAT as 'yyyy-mm-dd'
BLANKSASNULL 
TRUNCATECOLUMNS 
FILLRECORD
MAXERROR 100
ACCEPTINVCHARS as '?'
NULL as '\0';"""

Not too sure why I am receiving this error as it doesn't throw this error for any other single quotations.

Answer 1

When having issues with a query you can use the psycopg2 mogrify function to see if there is an issue with your string. It will attempt to interpolate any parameters as well so can be a good check. Since I didn't have a cursor object to call it on I did this instead:

print psycopg2.extensions.adapt(YOUR_QUERY).getquoted()

In your case this gives:

>>> import psycopg2
>>> print psycopg2.extensions.adapt(YOUR_QUERY).getquoted()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: A string literal cannot contain NUL (0x00) characters.

>>> print psycopg2.extensions.adapt('\\0').getquoted()
'\\0'
>>>

So you can see it doesn't like the '\\0' . If you escape the backslash as John Rotenstein suggests psycopg2 will accept the query but it may not give you what you want for your null value. The documentation suggests it should work if you can get the interpolation sorted out.