in reply to Re^2: Global symbol "$prepare" requires explicit package name
in thread Global symbol "$prepare" requires explicit package name

Try

$sth2 = $dbh->$prepare("update $schema.$table 
                        set $date_col = ?
                        where $where_col = ?;") or die;
$sth2->execute($date_new,1);

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poj

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Re^4: Global symbol "$prepare" requires explicit package name
by tukusejssirs (Beadle) on Sep 19, 2019 at 14:17 UTC

    And could someone tell why the following code does not work? It does not work either with or without placeholders, but with different errors.

    In this case, I want to select all unique dates from timestamps. It works as expected with select distinct cast(date as date) from table; issued directly in psql.

    # With placeholders
my $sth_test = $dbh->prepare("select distinct cast($date_col as date) 
+from ?;") or die;
$sth_test->execute($schema.$table);

# Errors (on execute())
INFO: The database has been opened successfully.
DBD::Pg::st execute failed: ERROR:  syntax error at or near "$1"
LINE 1: select distinct cast(date as date) from $1;
                                                       ^ at ./refresh_
+dates.pl line n.
DBD::Pg::st execute failed: ERROR:  syntax error at or near "$1"
LINE 1: select distinct cast(date as date) from $1;
                                                       ^ at ./refresh_
+dates.pl line n.


# Without placeholders
my $sth_test = $dbh->prepare("select distinct cast($date_col as date) 
+from $schema.$table;") or die;
$sth_test->execute();
$dbh->disconnect();

# Error (on disconnect)
DBI::db=HASH(0x32cec98)->disconnect invalidates 1 active statement han
+dle (either destroy statement handles or call finish on them before d
+isconnecting) at ./refresh_dates.pl line n.

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[d/l]
[select]

      Placeholders cannot be used for table names or schema names or anything within the schema. They may only be used for data.

[reply]

        The problem was that the statement handle was not finished. Solution is to add $sth_test->finish(); before disconnecting the database (src).<\p>

        However, I never used this command before and never encountered this error. Should I use it always before disconnecting the database?

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[d/l]

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