linux下沒有專門為mssql設計的訪問庫，不過介于mssql本是從sybase派生出來的，因此用來訪問sybase的庫自然也能訪問mssql，freetds就是這么一個實現(xiàn)。
perl中通常使用dbi來訪問數(shù)據(jù)庫，因此在系統(tǒng)安裝了freetds之后，可以使用dbi來通過freetds來訪問mssql數(shù)據(jù)庫，例子：
代碼如下:
using dbi;
my $cs = driver={freetds};server=主機;port=1433;database=數(shù)據(jù)庫;uid=sa;pwd=密碼;tds_version=7.1;charset=gb2312;
my $dbh = dbi->connect(dbi:odbc:$cs) or die $@;
因為本人不怎么用windows，為了研究qq群數(shù)據(jù)庫，需要將數(shù)據(jù)從mssql中遷移到mysql中，特地為了qq群數(shù)據(jù)庫安裝了一個windows server 2008和sql server 2008r2,不過過幾天評估就到期了，研究過mysql的workbench有從ms sql server遷移數(shù)據(jù)的能力，不過對于qq群這種巨大數(shù)據(jù)而且分表分庫的數(shù)據(jù)來說顯得太麻煩，因此寫了一個通用的perl腳本，用來將數(shù)據(jù)庫從mssql到mysql遷移，結合bash，很方便的將這二十多個庫上百張表給轉移過去了，perl代碼如下：
代碼如下:
#!/usr/bin/perl
use strict;
use warnings;
use dbi;
die usage: qq db\n if @argv != 1;
my $db = $argv[0];
print connectin to databases $db...\n;
my $cs = driver={freetds};server=mssql的服務器;port=1433;database=$db;uid=sa;pwd=mssql密碼;tds_version=7.1;charset=gb2312;
sub db_connect
{
my $src = dbi->connect(dbi:odbc:$cs) or die $@;
my $target = dbi->connect(dbi:mysql:host=mysql服務器, mysql用戶名, mysql密碼) or die $@;
return ($src, $target);
}
my ($src, $target) = db_connect;
print reading table schemas....\n;
my $q_tables = $src->prepare(select name from sysobjects where xtype = 'u' and name != 'dtproperties';);#獲取所有表名
my $q_key_usage = $src->prepare(select table_name, column_name from information_schema.key_column_usage;);#獲取表的主鍵
$q_tables->execute;
my @tables = ();
my %keys = ();
push @tables, @_ while @_ = $q_tables->fetchrow_array;
$q_tables->finish;
$q_key_usage->execute();
$keys{$_[0]} = $_[1] while @_ = $q_key_usage->fetchrow_array;
$q_key_usage->finish;
#獲取表的索引信息
my $q_index = $src->prepare(qq(
select t.name, c.name
from sys.index_columns i
inner join sys.tables t on t.object_id = i.object_id
inner join sys.columns c on c.column_id = i.column_id and i.object_id = c.object_id;
));
$q_index->execute;
my %table_indices = ();
while(my @row = $q_index->fetchrow_array)
{
my ($table, $column) = @row;
my $columns = $table_indices{$table};
$columns = $table_indices{$table} = [] if not $columns;
push @$columns, $column;
}
$q_index->finish;
#在目標mysql上創(chuàng)建對應的數(shù)據(jù)庫
$target->do(drop database if exists `$db`;) or die cannot drop old database $db\n;
$target->do(create database `$db` default charset = utf8 collate utf8_general_ci;) or die cannot create database $db\n;
$target->disconnect;
$src->disconnect;
my $total_start = time;
for my $table(@tables)
{
my $pid = fork;
unless($pid)
{
($src, $target) = db_connect;
my $start = time;
$src->do(use $db;);
#獲取表結構，用來生成mysql用的ddl
my $q_schema = $src->prepare(select column_name, is_nullable, data_type, character_maximum_length from information_schema.columns where table_name = ? order by ordinal_position;);
$target->do(use `$db`;);
$target->do(set names utf8;);
my $key_column = $keys{$table};
my $ddl = create table `$table` ( \n;
$q_schema->execute($table);
my @fields = ();
while(my @row = $q_schema->fetchrow_array)
{
my ($column, $nullable, $datatype, $length) = @row;
my $field = `$column` $datatype;
$field .= ($length) if $length;
$field .= primary key if $key_column eq $column;
push @fields, $field;
}
$ddl .= join(,\n, @fields);
$ddl .= \n) engine = myisam;\n\n;
$target->do($ddl) or die cannot create table $table\n;
#創(chuàng)建索引
my $indices = $table_indices{$table};
if($indices)
{
for(@$indices)
{
$target->do(create index `$_` on `$table`(`$_`);\n) or die cannot create index on $db.$table$.$_\n;
}
}
#轉移數(shù)據(jù)
my @placeholders = map {'?'} @fields;
my $insert_sql = insert delayed into $table values( .(join ', ', @placeholders) . );\n;
my $insert = $target->prepare($insert_sql);
my $select = $src->prepare(select * from $table;);
$select->execute;
$select->{'longreadlen'} = 1000;
$select->{'longtruncok'} = 1;
$target->do(set autocommit = 0;);
$target->do(start transaction;);
my $rows = 0;
while(my @row = $select->fetchrow_array)
{
$insert->execute(@row);
$rows++;
}
$target->do(commit;);
#結束，輸出任務信息
my $elapsed = time - $start;
print child process $$ for table $db.$table done, $rows records, $elapsed seconds.\n;
exit(0);
}
}
print waiting for child processes\n;
#等待所有子進程結束
while (wait() != -1) {}
my $total_elapsed = time - $total_start;
print all tasks from $db finished, $total_elapsed seconds.\n;
這個腳本會根據(jù)每一個表fork出一個子進程和相應的數(shù)據(jù)庫連接，因此做這種遷移之前得確保目標mysql數(shù)據(jù)庫配置的最大連接數(shù)能承受。
然后在bash下執(zhí)行
代碼如下:
for x in {1..11};do ./qq.pl quninfo$x; done
for x in {1..11};do ./qq.pl groupdata$x; done
就不用管了，腳本會根據(jù)mssql這邊表結構來在mysql那邊創(chuàng)建一樣的結構并配置索引。