How can I insert NULL data into MySQL database with Python?

Question

I\'m getting a weird error when inserting some data from a Python script to MySQL. It\'s basically related to a variable being blank that I am inserting. I take it that MyS

Answer 1

Why not set the variable equal to some string like 'no price' and then filter this out later when you want to do math on the numbers?

filter(lambda x: x != 'no price',list_of_data_from_database)

Answer 2

if the col1 is char, col2 is int, a trick could be:

insert into table (col1, col2) values (%s, %s) % ("'{}'".format(val1) if val1 else "NULL", val2 if val2 else "NULL");

you do not need to add ' ' to %s, it could be processed before pass value to sql.

this method works when execute sql with session of sqlalchemy, for example session.execute(text(sql))

ps: sql is not tested yet

Answer 3

When using mysqldb and cursor.execute(), pass the value None, not "NULL":

value = None
cursor.execute("INSERT INTO table (`column1`) VALUES (%s)", (value,))

Found the answer here

Answer 4

Do a quick check for blank, and if it is, set it equal to NULL:

if(!variable_to_insert)
    variable_to_insert = "NULL"

...then make sure that the inserted variable is not in quotes for the insert statement, like:

insert = "INSERT INTO table (var) VALUES (%s)" % (variable_to_insert)
...

not like:

insert = "INSERT INTO table (var) VALUES ('%s')" % (variable_to_insert)
...