The keys points from this code are: find is used to query the database for the entity with the same primary key values as the object passed to addorupdate. two values are passed to find since orderline has a two-part composite key. if find returns null it means that no orderline with the given key was found.. On duplicate key update inserts or updates a row, the last_insert_id() function returns the auto_increment value. the on duplicate key update clause can contain multiple column assignments, separated by commas.. Recall that in mysql, a primary key is simply a unique index named primary. any data that violates any unique index will cause the same problem. this situation occurs frequently. for example, i might export some data to a spreadsheet, send it to a client, and the client might update or add some data and return the spreadsheet to me..
Description. insert on duplicate key update is a mariadb/mysql extension to the insert statement that, if it finds a duplicate unique or primary key, will instead perform an update.. the row/s affected value is reported as 1 if a row is inserted, and 2 if a row is updated, unless the api's client_found_rows flag is set.. if more than one unique index is matched, only the first is updated.. 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.. Uses the specified functions and argument to add a key/value pair to the concurrentdictionary<tkey,tvalue> if the key does not already exist, or to update a key/value pair in the concurrentdictionary<tkey,tvalue> if the key already exists..
