Python MySQL query using string comparison in where clause

Question

I have a strange issue where I can't get an SQL query with parameter to work with a string comparison in the where clause - I don't get a row back. when i connect to the MySQL db via bash, the query works.

python 3.7.3
mysql-connector-python==8.0.11
mysql 5.7

works (getting my row):

select * from my_table where my_column = 'my_string';

also works (getting my row):

cursor.execute(
    """
        select *
        from my_table
        where my_column = 'my_string'
    """
)

doesn't work (cursor.fetchall() is []):

cursor.execute(
    """
        select *
        from my_table
        where my_column = '%s'
    """,
    ('my_string')
)

there was a comment that's now removed - writing ('my_string',) with a comma after the string. please add as answer so i can promote it as correct answer! — tscherg
– tscherg, Commented Jul 16, 2019 at 8:53

Dušan Maďar · Accepted Answer · 2019-07-16 09:00:27Z

1

Be careful with tuples. I think you need ('my_string',).

FYI I wrote the original comment mentioned by @tscherg in his comment below the question.

answered Jul 16, 2019 at 9:00

Dušan Maďar

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1 Comment

tscherg Over a year ago

this along with removing the quotes around %s did it!

Daniel Roseman · Accepted Answer · 2019-07-16 08:50:44Z

1

Remove the quotes:

cursor.execute(
    """
        select *
        from my_table
        where my_column = %s
    """,
    ('my_string')
)

answered Jul 16, 2019 at 8:50

Daniel Roseman

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1 Comment

tscherg Over a year ago

that's not it. getting a MySQL Error (42000) telling me to check the syntax near %s

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