#!/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 $cs=”DRIVER={FreeTDS};SERVER=MSSQL的服务器;PORT=1433;DATABASE=$db;UID=sa;PWD=MSSQL密码;TDS_VERSION=7.1;charset=gb2312″;
sub db_connect
{
my $src=https://www.jb51.net/article/DBI->connect(“dbi:ODBC:$cs”) or die $@;
my $target=DBI->connect(“dbi:mysql:host=MySQL服务器”, “MySQL用户名”, “MySQL密码”) 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’;”);#获取所有表名
my $q_key_usage=$src->prepare(“SELECT TABLE_NAME, COLUMN_NAME from INFORMATION_SCHEMA.KEY_COLUMN_USAGE;”);#获取表的主键
$q_tables->execute;
my @tables=();
my %keys=();
push @tables, @_ while @_=$q_tables->fetchrow_array;
$q_tables->finish;
$q_key_usage->execute();
$keys{$_[0]}=$_[1] while @_=$q_key_usage->fetchrow_array;
$q_key_usage->finish;
#获取表的索引信息
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;
#在目标MySQL上创建对应的数据库
$target->do(“DROP DATABASE IF EXISTS `$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;”);
#获取表结构，用来生成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”;
#创建索引
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”;
}
}
#转移数据
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;”);
#结束，输出任务信息
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”;
#等待所有子进程结束
while (wait() !=-1) {}
my $total_elapsed=time – $total_start;
print “All tasks from $db finished, $total_elapsed seconds.\n”;
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