in reply to Re^3: return string from query (DBI, MySQL) got truncated when trying to generating statement dynamically for MySQL
in thread return string from query (DBI, MySQL) got truncated when trying to generating statement dynamically for MySQL
I could get 31.$dbh->do('SET SESSION group_concat_max_len = 2048');
#!perl use strict; use DBI; my $dbh = connect(...); $dbh->do('SET SESSION group_concat_max_len = 2048');; my $pvt_col = 'prod'; my $count = 'count'; my $table = 'prod_test'; #test data create_test_db($ARGV[0] || 10); my $s1 =<<S1; 'SUM(CASE WHEN $pvt_col IS NULL THEN $count ELSE 0 END) AS Total,' S1 my $s2 =<<S2; CONCAT( '(SUM(CASE WHEN $pvt_col = ''',$pvt_col,''' THEN $count ELSE 0 END)) AS ',$pvt_col ) S2 my $sql1 = <<SQL1; SELECT CONCAT($s1,GROUP_CONCAT(DISTINCT $s2)) FROM ( SELECT $pvt_col,count(*) AS count FROM $table GROUP BY $pvt_col WITH ROLLUP) as temptbl SQL1 my $tmp = $dbh->selectrow_array($sql1); my $sql2 = <<SQL2; SELECT $tmp FROM ( SELECT $pvt_col, count(*) AS $count FROM $table GROUP BY $pvt_col WITH ROLLUP) as temptbl SQL2 my @f = $dbh->selectrow_array($sql2); print "@f\n"; sub create_test_db { my $no = shift; #$dbh->do("DROP TABLE $table"); $dbh->do("CREATE TABLE IF NOT EXISTS $table ( id int(11) NOT NULL AUTO_INCREMENT, $pvt_col varchar(20) NOT NULL, PRIMARY KEY (id))"); $dbh->do("DELETE FROM $table"); for my $n (1..$no){ for (1..$n){ $dbh->do("INSERT INTO $table VALUES (?,?)",undef,undef,sprintf " +prod%02d",$n); } } }
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