I've written this example script to illustrate what I'm attempting to do:

#my @col = ("machine","runas");
#my @val = ("bar","faa");
my $col = "machine";
my $val = "bar";
my $dbName = "fooDB.db";

#Create DB connection
my $dbh = DBI->connect(          # connect to your database, create if
    "dbi:SQLite:dbname=$dbName", # DSN: dbi, driver, database file
    "",                          # no user
    "",                          # no password
   { RaiseError => 1 },         # complain if something goes wrong
) or die $DBI::errstr;

#Create Table
$dbh->do('create table schedules
        (schedId INTEGER PRIMARY KEY,
        schedName TEXT,
        machine TEXT,
        runas TEXT,
        owner TEXT)' );

#Insert 1 row
my $sth = $dbh->prepare_cached("INSERT into schedules (schedName) valu
+es ('foo')")
        or die "Couldn't prepare statement: " . $dbh->errstr;
$sth->execute()
        or die "Couldn't execute statement: " . $sth->errstr;

#Get row ID
my $rowId = $dbh->func('last_insert_rowid');

#Do an update with mutiple placeholders
my $sth1 = $dbh->prepare_cached("UPDATE schedules SET ? = ? WHERE sche
+dId = ?")
        or die "Couldn't prepare statement: " . $dbh->errstr;

#Try with bind_param_array
#$sth1->bind_param_array(1, @col);
#$sth1->bind_param_array(2, @val);
#$sth1->bind_param_array(3, $rowId); # scalar will be reused for each 
+row
#$sth1->execute_array()

$sth1->execute($col,$val,$rowId)
        or die "Couldn't execute statement: " . $sth->errstr;
[download]

No matter how I use this, with bind_param_array or with straight scalars, I get the same error:

DBD::SQLite::db prepare_cached failed: near "?": syntax error at ./foo
+.pl line 37.
DBD::SQLite::db prepare_cached failed: near "?": syntax error at ./foo
+.pl line 37.
[download]

You cannot have a fieldname represented by a "?" placeholder (unless you use some trickery as Anonymous Monk said). The prepare method of DBI asks the database to look at the SQL before it is executed and already prepare an execution plan.

Not knowing the fields to use at the moment of preparing the statement handle will not allow the database to prepare a plan, hence the error.

One more comment: having both RaiseError on and using die statements is overkill.

From the docs:

The RaiseError attribute can be used to force errors to raise exceptions rather than simply return error codes in the normal way. It is "off" by default. When set "on", any method which results in an error will cause the DBI to effectively do a die("$class $method failed: $DBI::errstr"), where $class is the driver class and $method is the name of the method that failed.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

Re: How to get a placeholder to keep the current column value?