UPDATE table using INNER JOIN - help!

I want to update table 'tourneyteamsISF' fields 'pointsfavor' and 'pointscontra' from table 'tourneygamesISF' fiels 'op1score' and 'op2score' from a certain ID.

For example:

Table name = tourneygamesISF 

op1(name of row) vs. op2    -  op1score = 25 - op2score =  20

I want to update this:

op1: (from: tourneygamesISF) = ID in tourneyteamsISF

+ pointsfavor = 25 (to: tourneyteamsISF)
+ pointscontra  = 20 (to: tourneyteamsISF)

op2: (from: tourneygamesISF) = ID in tourneyteamsISF

+ pointsfavor = 20 (to: tourneyteamsISF)
+ pointscontra  = 25 (to: tourneyteamsISF)

I have the following until now

UPDATE tourneyteamsISF 
INNER JOIN tourneygamesISF g1 ON (tourney开发者_如何学运维teamsISF.ID = g1.op1)
INNER JOIN tourneygamesISF g2 ON (tourneyteamsISF.ID = g2.op2)
SET pointsfavor = pointsfavor 
  + IF(g1.op1score > g1.op2score, g1.op1score - g1.op2score, 0) 
  + IF(g2.op2score > g2.op1score, g2.op2score - g2.op1score, 0)
, pointscontra = pointscontra 
  + IF(g1.op1score < g1.op2score, g1.op2score - g1.op1score, 0) 
  + IF(g2.op2score < g2.op1score, g2.op1score - g2.op2score, 0)
WHERE ID = 1;   

But it gives the error: Column 'ID' in where clause is ambiguous

My tables are like this:

TABLE tourneyteamsISF
  ID integer autoincrement primary key,
  name varchar,
  pointsfavor integer,
  pointscontra integer

TABLE tourneygamesISF
  ID integer autoincrement primary key,
  op1 integer,
  op2 integer,
  op1score integer, /*score for team1*/
  op2score integer /*score for team2*/

I know that it has to do something with naming the id of table teams and games but I am stuck and confused. I will appreciate all the help I can get.

WHERE ID = 1; <- here is your problem. Add the table name before it and it will compile without any problems.

eg. WHERE g1.ID = 1;

This error is occuring because SQL cannot identify which ID column you want to use from the tables in your SELECT statment.

it has to be like this - WHERE g1.ID = 1