Introduction to PowerShell Focused on SQL Server Piotr Palka

Basics of PowerShell Scripting language Command line interpreter Object oriented (not text based) “Cmdlet”: Verb – noun –parameter Get-Process Get-Help

Enable SQL Server integration Start “PowerShell ISE” Set-ExecutionPolicy -ExecutionPolicy RemoteSigned Requires local admin priviledges Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy RemoteSigned -Force No special privileges needed Import-Module SqlServer

Variables Sample script: Special variables $varDate = Get-Date $var1 "***************************" "Day of the year : " + $varDate.DayOfYear $varDate.AddDays(4) Special variables $_ - The current pipeline object $Args – parameters for current function call $Error – last error

Comparison Operators 5 > 3 is not comparison in PowerShell!!!!!!! if ( 5 > 3 ) { "T" } else { "F" } Result: F What happened?

Comparison Operators Use instead: if ( 5 -ge 3 ) { "T" } else { "F" } -eq Equal -ne Not equal -ge Greater than or equal -gt Greater than -lt Less than -le Less than or equal And many more…

Logical operators -and Logical And -or Logical Or -not logical not if (( 5 -ge 3 ) -and (5 -eq 4)) { "T" } else { "F" }

Basic queries Invoke-Sqlcmd -ServerInstance . -Database TestDB1 -Query "select GetDate()" Demo – accessing query results

Iterations ForEach Collections can be created as: Performs an operation against each item in a collection Collections can be created as: Hardcoded list (in a script), e.g. list of server names Loaded from SQL query Loaded from file ForEach can be used to run scripts on multiple servers/DBs Demo

Monitoring and mass actions For Each database: SELECT physical_name, state, state_desc, size, max_size, growth FROM sys.database_files If file meets logical condition do something: if ($f.size -ge 2000) { Backup file } We can use best of scripting language and SQL

Scheduling

Questions?