Insert on duplicate key update leaves unmentioned columns unchanged on update but gives them default values on insert. with replace into, unmentioned columns always get default values, never existing values.. 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.. When updating summary tables we typically use on duplicate key update, a mysql extension to insert statements since version 4.1, that allows a record to either be inserted or updated in one query. for example, with this 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.. 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.. The problem is in the function name strpos being at the beginning, the position will be 0, so 0 will be treated as false. the position of needle text placed anywhere but the beginning will be greater than 0, meaning true. you need to check against not being false within the if condition and make.
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