functions/Set-DbaDbMirror.ps1

#ValidationTags#Messaging,FlowControl,Pipeline,CodeStyle#
function Set-DbaDbMirror {
    <#
        .SYNOPSIS
            Sets properties of database mirrors.
 
        .DESCRIPTION
            Sets properties of database mirrors.
 
        .PARAMETER SqlInstance
            SQL Server name or SMO object representing the SQL Server to connect to. This can be a collection and receive pipeline input to allow the function
            to be executed against multiple SQL Server instances.
 
        .PARAMETER SqlCredential
            Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
     
        .PARAMETER Database
            The target database.
     
        .PARAMETER Partner
            Sets the partner fqdn.
     
        .PARAMETER Witness
            Sets the witness fqdn.
     
        .PARAMETER SafetyLevel
            Sets the mirroring safety level.
     
        .PARAMETER State
            Sets the mirror state.
     
        .PARAMETER InputObject
            Allows piping from Get-DbaDatabase.
     
       .PARAMETER WhatIf
            Shows what would happen if the command were to run. No actions are actually performed.
 
        .PARAMETER Confirm
            Prompts you for confirmation before executing any changing operations within the command.
     
        .PARAMETER EnableException
            By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
            This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
            Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
 
        .NOTES
            Tags: Mirror, HA
            Author: Chrissy LeMaire (@cl), netnerds.net
            dbatools PowerShell module (https://dbatools.io, clemaire@gmail.com)
            Copyright (C) 2016 Chrissy LeMaire
            License: MIT https://opensource.org/licenses/MIT
 
        .LINK
            https://dbatools.io/Set-DbaDbMirror
 
        .EXAMPLE
            PS C:\> Set-DbaDbMirror -SqlInstance sql2005 -Database dbatools -Partner TCP://SQL2008.ad.local:5374
 
            Prompts for confirmation then sets the partner to TCP://SQL2008.ad.local:5374 for the database "dbtools"
 
        .EXAMPLE
            PS C:\> Set-DbaDbMirror -SqlInstance sql2005 -Database dbatools -Witness TCP://SQL2012.ad.local:5502 -Confirm:$false
 
            Does not prompt for confirmation and sets the witness to TCP://SQL2012.ad.local:5502 for the database "dbtools"
     
        .EXAMPLE
            PS C:\> Get-DbaDatabase -SqlInstance sql2005 | Out-GridView -Passthru | Set-DbaDbMirror -SafetyLevel Full -Confirm:$false
 
            Sets the safety level to Full for databases selected from a gridview. Does not prompt for confirmation.
 
        .EXAMPLE
            PS C:\> Set-DbaDbMirror -SqlInstance sql2005 -Database dbatools -State Suspend -Confirm:$false
 
            Does not prompt for confirmation and sets the state to suspend for the database "dbtools"
    #>

    [CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'High')]
    param (
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [string[]]$Database,
        [string]$Partner,
        [string]$Witness,
        [ValidateSet('Full','Off','None')]
        [string]$SafetyLevel,
        [ValidateSet('ForceFailoverAndAllowDataLoss', 'Failover', 'RemoveWitness', 'Resume', 'Suspend', 'Off')]
        [string]$State,
        [parameter(ValueFromPipeline)]
        [Microsoft.SqlServer.Management.Smo.Database[]]$InputObject,
        [switch]$EnableException
    )
    process {
        if ((Test-Bound -ParameterName SqlInstance) -and (Test-Bound -Not -ParameterName Database)) {
            Stop-Function -Message "Database is required when SqlInstance is specified"
            return
        }
        foreach ($instance in $SqlInstance) {
            $InputObject += Get-DbaDatabase -SqlInstance $instance -SqlCredential $SqlCredential -Database $Database
        }
        
        foreach ($db in $InputObject) {
            try {
                if ($Partner) {
                    if ($Pscmdlet.ShouldProcess($db.Parent.Name, "Setting partner on $db")) {
                        # use t-sql cuz $db.Alter() doesnt always work against restoring dbs
                        $db.Parent.Query("ALTER DATABASE $db SET PARTNER = N'$Partner'")
                    }
                }
                elseif ($Witness) {
                    if ($Pscmdlet.ShouldProcess($db.Parent.Name, "Setting witness on $db")) {
                        $db.Parent.Query("ALTER DATABASE $db SET WITNESS = N'$Witness'")
                    }
                }
                
                if ($SafetyLevel) {
                    if ($Pscmdlet.ShouldProcess($db.Parent.Name, "Changing safety level to $SafetyLevel on $db")) {
                        $db.Parent.Query("ALTER DATABASE $db SET PARTNER SAFETY $SafetyLevel")
                        # $db.MirroringSafetyLevel = $SafetyLevel
                    }
                }
                
                if ($State) {
                    if ($Pscmdlet.ShouldProcess($db.Parent.Name, "Changing mirror state to $State on $db")) {
                        $db.ChangeMirroringState($State)
                        $db.Alter()
                        $db
                    }
                }
            }
            catch {
                Stop-Function -Message "Failure" -ErrorRecord $_
            }
        }
    }
}