On Duplicate Key Update All Columns
The only addition to the insert statement is the on duplicate key update clause where you specify a list of column-value-pair assignments in case of duplicate. basically, the statement first tries to insert a new row into the table.. 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.. Select syntax”, and section 13.2.5.2, “insert on duplicate key update syntax”. inserting into a table requires the insert privilege for the table. if the on duplicate key update clause is used and a duplicate key causes an update to be performed instead, the statement requires the update privilege for the columns to be updated..
Insert into t1 (a, b, c) select a, b, c from t2 on duplicate key update b = values(b); error 1052 (23000): column 'b' in field list is ambiguous multi-table updates can be tricky if there is ambiguity in column names.. When doing the insert, if all the primary key columns are the same as an existing row, then it will trigger the on duplicate key update portion of the syntax, which should only then include what to do with the non-primary key columns.. Thewebfellas. we build web & mobile applications. < all articles. 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..
