functions/Remove-DbaDbMirror.ps1

#ValidationTags#Messaging,FlowControl,Pipeline,CodeStyle#
function Remove-DbaDbMirror {
    <#
        .SYNOPSIS
            Removes database mirrors.
 
        .DESCRIPTION
            Removes database mirrors. Does not set databases in recovery to recovered.
 
        .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
            The partner fqdn.
     
        .PARAMETER Witness
            The witness fqdn.
     
        .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 localhost
 
            Returns all Endpoint(s) on the local default SQL Server instance
 
        .EXAMPLE
            PS C:\> Set-DbaDbMirror -SqlInstance localhost, sql2016
 
            Returns all Endpoint(s) for the local and sql2016 SQL Server instances
    #>

    [CmdletBinding(SupportsShouldProcess, ConfirmImpact = 'High')]
    param (
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [string[]]$Database,
        [parameter(ValueFromPipeline)]
        [Microsoft.SqlServer.Management.Smo.Database[]]$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 $InputObject) {
            if ($Pscmdlet.ShouldProcess($db.Parent.Name, "Turning off mirror for $db")) {
                # use t-sql cuz $db.Alter() doesnt always work against restoring dbs
                try {
                    try {
                        $db.ChangeMirroringState([Microsoft.SqlServer.Management.Smo.MirroringOption]::Off)
                        $db.Alter()
                    }
                    catch {
                        try {
                            $db.Parent.Query("ALTER DATABASE $db SET PARTNER OFF")
                        }
                        catch {
                            Stop-Function -Message "Failure on $($db.Parent) for $db" -ErrorRecord $_ -Continue
                        }
                    }
                    [pscustomobject]@{
                        ComputerName = $db.ComputerName
                        InstanceName = $db.InstanceName
                        SqlInstance  = $db.SqlInstance
                        Database     = $db.Name
                        Status       = "Removed"
                    }
                }
                catch {
                    Stop-Function -Message "Failure on $($db.Parent.Name)" -ErrorRecord $_
                }
            }
        }
    }
}