It isn't saying that there is a duplicate entry in the table already, it is saying that there is already one entry in there with that value for the primary key and it is refusing to insert a second for that reason.. The primary key column is unique and it will not accept the duplicate entry. case 2: unique data field. you are trying to add a column to an existing table which contains data and set it as unique.. I'm trying to insert a huge list of users to a mysql database but everytime i try i get the error: #1062 - duplicate entry '' for key 2 it gives me this because the 2nd column is blank on quite.
Tour start here for a quick overview of the site help center detailed answers to any questions you might have meta discuss the workings and policies of this site. The above test case work fine if we split the multi-values insert sentence to single-value sentence as following: insert into t1(f1) values(1),(2); to: insert into t1(f1) values(1); insert into t1(f1) values(2); because we can write a separate "set insert_id=n" sentence for every insert row sentence to binlog.. The on duplicate key update clause can contain multiple column assignments, separated by commas. in assignment value expressions in the on duplicate key update clause, you can use the values(col_name) function to refer to column values from the insert portion of the insert on duplicate key update statement..
