Also, although unnecessary for the on duplicate key update method to function properly, we’ve also opted to utilize user variables so we don’t need to specify the actual values we want to insert or update more than once.. On duplicate key update `pk` = last_insert_id(`pk`) after that statement last_insert_id() should return the last autoincrement id or in case of existing row the id of that. but now it returns '0' in case of an existing (duplicate key) row.. On duplicate key update value_a = 6; we will have a deadlock , the first connection is waiting for the unlock between 2018–05–01 and 2018–07–11 to insert the value in 2018–06–01..
The statement above sets the value of the c1 to its current value specified by the expression values(c1) plus 1 if there is a duplicate in unique index or primary key. mysql insert on duplicate key update example. let’s take a look at an example of using the insert on duplicate key update to understand how it works.. Conditional duplicate key updates with mysql. in one of our larger rails apps the sheer volume of data we process means we’ve had to rely more and more on direct sql queries, denormalised tables and summary tables to speed things up.. Use mysql’s non-standard on duplicate key update extension to accomplish the insert and update in a single step. as with the non-standard insert ignore above, this is probably the fastest method: insert into t1(a, b, c) select d, e, f from t2 on duplicate key update b = e, c = f;.