Migrating from SQL Server 2005 to 2008 requires careful planning due to several architectural changes. While the backup-restore method works in many cases, there are important compatibility considerations:

-- Sample backup command for SQL 2005
BACKUP DATABASE [YourDB] TO DISK = N'C:\Backup\YourDB.bak' 
WITH COMPRESSION, STATS = 10
GO

The SQL Server 2008 introduces new features that may affect backward compatibility:

• New data types (DATE, TIME, DATETIME2)
• Change in FILESTREAM implementation
• Modified T-SQL syntax in some cases

Here's a reliable migration approach:

-- 1. Prepare target server
-- Install SQL Server 2008 with compatibility mode options
-- (Use same collation as source server)

-- 2. Script out logins (example for single login)
SELECT 'CREATE LOGIN [' + name + '] WITH PASSWORD = 0x' + 
CONVERT(VARCHAR(MAX), CAST(password AS VARBINARY(256)), 2) + ' HASHED'
FROM sys.sql_logins
WHERE name = 'YourLogin'

SQL Server Reporting Services (SSRS) underwent significant changes:

-- RS.exe script to migrate reports (save as Migration.rss)
Public Sub Main()
    Dim items As CatalogItem() = rs2005.ListChildren("/", True)
    For Each item As CatalogItem In items
        If item.Type = ItemTypeEnum.Report Then
            Dim definition As Byte() = rs2005.GetReportDefinition(item.Path)
            rs2008.CreateCatalogItem(item.Type, item.Name, item.Path, False, definition, Nothing)
        End If
    Next
End Sub

• Update database compatibility level: ALTER DATABASE YourDB SET COMPATIBILITY_LEVEL = 100
• Test all stored procedures and functions
• Validate linked server connections
• Verify job schedules in SQL Agent

If you encounter problems during restore:

-- Force restore with CONTINUE_AFTER_ERROR (use cautiously)
RESTORE DATABASE [YourDB] FROM DISK = 'C:\Backup\YourDB.bak'
WITH MOVE 'YourDB_Data' TO 'C:\Data\YourDB.mdf',
MOVE 'YourDB_Log' TO 'C:\Data\YourDB.ldf',
CONTINUE_AFTER_ERROR, STATS = 10

Remember to test the migration process in a non-production environment first and schedule appropriate downtime for production systems.

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Migrating from SQL Server 2005 to 2008 requires careful planning due to several architectural changes. The most straightforward method is backup/restore, but you'll need to verify database compatibility first:

-- Check compatibility level before migration
SELECT name, compatibility_level 
FROM sys.databases 
WHERE name = 'YourDatabaseName';

The fundamental process involves:

1. Creating a full backup from SQL Server 2005
2. Restoring to SQL Server 2008 instance

-- SQL 2005 backup command
BACKUP DATABASE YourDatabase
TO DISK = 'C:\Backups\YourDatabase.bak'
WITH COMPRESSION, STATS = 10;

-- SQL 2008 restore command
RESTORE DATABASE YourDatabase
FROM DISK = 'C:\Backups\YourDatabase.bak'
WITH MOVE 'YourDatabase_Data' TO 'C:\Data\YourDatabase.mdf',
MOVE 'YourDatabase_Log' TO 'C:\Data\YourDatabase.ldf',
RECOVERY, STATS = 10;

SQL Server 2008 introduced several breaking changes:

• Deprecated features like sp_dropalias
• New reserved keywords (MERGE, etc.)
• Changes to the query optimizer

-- Check for deprecated features
SELECT * 
FROM sys.dm_os_performance_counters
WHERE object_name LIKE '%Deprecated%';

SSRS underwent significant architectural changes:

1. Backup encryption keys from 2005
2. Install new 2008 Reporting Services
3. Restore report server databases
4. Apply encryption keys

-- RS 2005 key backup
rsconfig -e -m 2005Server -u Domain\Admin -p Password -f C:\backup\rsdbkey.key

-- RS 2008 key restore
rskeymgmt -a -f C:\backup\rsdbkey.key -p Password

Essential verification steps:

-- Check database status
SELECT name, state_desc, compatibility_level
FROM sys.databases;

-- Test critical stored procedures
EXEC sp_testCriticalProcedure @param1 = 'test';

Microsoft provides the SQL Server Upgrade Advisor tool which:

• Scans for compatibility issues
• Generates detailed reports
• Provides remediation guidance

Always run this tool before attempting migration. Download it from Microsoft's official site.