Create string as database insert-statement with NULL values in C

Applications Programming
1

I have C code (gcc) using the mysql.h library to insert data in a database table:

/* Insert event */
void insert_event (MYSQL *conn, char *event, char *date) {
  char insert_query[99];
  if (!strcmp(event, "final")) {
    snprintf(insert_query, sizeof(insert_query), "insert into events values ('%s', NULL);", event);
  } else {
    snprintf(insert_query, sizeof(insert_query), "insert into events values ('%s', '%s');", event, date);
  }
  mysql_query(conn, insert_query);
}

Data would look something like this

event   date
-----   ----
A       2023-12-01
B       2024-01-11
C       2024-01-22
final

The question is whether the above code can be refactored, since my current code (consisting of about 20 fields) differs only by this one date field.
I was hoping to turn the whole if-block into something as follows:

snprintf(insert_query, sizeof(insert_query), "insert into events values ('%s', '%s');", event, (strcmp(event, "final")) ? date : NULL);

This will not work, as NULL values are not to be quoted. Perhaps there is a more elegant solution?

2

try something along

snprintf(insert_query, sizeof(insert_query), "insert into events values ('%s', CASE WHEN event = 'final' THEN NULL ELSE '%s' END)", event, date);

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