Python MySQL 语法错误

Question

I've been trying to work out where I've been going for most of the day, and still can't work it out, been staring at it too long and I'm sqill very early in my learning of Python & MySQL.

The query I've built is:

query = "UPDATE `db`.`%s" % table + "` SET %s" % table + "`.`%s" % field + "` = `%s" % daychangeperc + "` WHERE (`db`.`%s" % table + "`.`id` = %s" % rowid +") LIMIT 1;"

The error I'm getting is:

_mysql_exceptions.ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' . DayChange = '-0.00736251627767' WHERE ( outofthe_finance . test1 . id` = 1) ' at line 1")

Anyone able to point out where I'm going wrong? I'm sure it's probably obvious for many.

Thanks in advance.

Answer 1

That's pretty messy, perhaps try doing it like this instead:

query = """UPDATE db.%s SET %s.%s = %s WHERE db.%s.id = %s LIMIT 1""" % (table,table,field,daychangeperc,table,rowid)

Answer 2

First, here is your query re-written so that all of the arguments for your format string come at the end:

query = "UPDATE `db`.`%s` SET %s`.`%s` = `%s` WHERE (`db`.`%s`.`id` = %s) LIMIT 1;" \
 %(table,table,field,daychangeperc,table,rowid)

When you look at it this way, you can see that after the SET keyword you have some unbalanced back-ticks . I think this is the issue, and is hard to see because of how you wrote your string.