functions/Get-DbaDatabaseState.ps1

#ValidationTags#Messaging,FlowControl,Pipeline#
function Get-DbaDatabaseState {
    <#
.SYNOPSIS
Gets various options for databases, hereby called "states"
 
.DESCRIPTION
Gets some common "states" on databases:
 - "RW" options : READ_ONLY or READ_WRITE
 - "Status" options : ONLINE, OFFLINE, EMERGENCY
 - "Access" options : SINGLE_USER, RESTRICTED_USER, MULTI_USER
 
Returns an object with SqlInstance, Database, RW, Status, Access
 
.PARAMETER SqlInstance
The SQL Server that you're connecting to
 
.PARAMETER SqlCredential
Credential object used to connect to the SQL Server as a different user
 
.PARAMETER Database
The database(s) to process - this list is auto-populated from the server. If unspecified, all databases will be processed.
 
.PARAMETER ExcludeDatabase
The database(s) to exclude - this list is auto-populated from the server
 
.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: Databases
Author: niphlod
 
Website: https://dbatools.io
Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0
 
.LINK
https://dbatools.io/Get-DbaDatabaseState
 
.EXAMPLE
Get-DbaDatabaseState -SqlInstance sqlserver2014a
 
Gets options for all databases of the sqlserver2014a instance
 
.EXAMPLE
Get-DbaDatabaseState -SqlInstance sqlserver2014a -Database HR, Accounting
 
Gets options for both HR and Accounting database of the sqlserver2014a instance
 
.EXAMPLE
Get-DbaDatabaseState -SqlInstance sqlserver2014a -Exclude HR
 
Gets options for all databases of the sqlserver2014a instance except HR
 
.EXAMPLE
'sqlserver2014a', 'sqlserver2014b' | Get-DbaDatabaseState
 
Gets options for all databases of sqlserver2014a and sqlserver2014b instances
 
#>

    [CmdletBinding()]
    Param (
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [Alias("Credential")]
        [PSCredential]
        $SqlCredential,
        [Alias("Databases")]
        [object[]]$Database,
        [object[]]$ExcludeDatabase,
        [switch][Alias('Silent')]$EnableException
    )

    begin {
        $UserAccessHash = @{
            'Single'     = 'SINGLE_USER'
            'Restricted' = 'RESTRICTED_USER'
            'Multiple'   = 'MULTI_USER'
        }
        $ReadOnlyHash = @{
            $true  = 'READ_ONLY'
            $false = 'READ_WRITE'
        }
        $StatusHash = @{
            'Offline'       = 'OFFLINE'
            'Normal'        = 'ONLINE'
            'EmergencyMode' = 'EMERGENCY'
            'Restoring'     = 'RESTORING'
        }
        
        function Get-DbState($db) {
            $base = [PSCustomObject]@{
                'Access' = ''
                'Status' = ''
                'RW'     = ''
            }
            $base.RW = $ReadOnlyHash[$db.ReadOnly]
            $base.Access = $UserAccessHash[$db.UserAccess.toString()]
            foreach ($status in $StatusHash.Keys) {
                if ($db.Status -match $status) {
                    $base.Status = $StatusHash[$status]
                    break
                }
            }
            return $base
        }
        
    }
    process {
        foreach ($instance in $SqlInstance) {
            Write-Message -Level Verbose -Message "Connecting to $instance"
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }
            $all_dbs = $server.Databases
            $dbs = $all_dbs | Where-Object { @('master', 'model', 'msdb', 'tempdb', 'distribution') -notcontains $_.Name }
            
            if ($Database) {
                $dbs = $dbs | Where-Object Name -In $Database
            }
            if ($ExcludeDatabase) {
                $dbs = $dbs | Where-Object Name -NotIn $ExcludeDatabase
            }
            foreach ($db in $dbs) {
                $db_status = Get-DbState $db
                
                [PSCustomObject]@{
                    SqlInstance  = $server.Name
                    InstanceName = $server.ServiceName
                    ComputerName = $server.NetName
                    DatabaseName = $db.Name
                    RW           = $db_status.RW
                    Status       = $db_status.Status
                    Access       = $db_status.Access
                    Database     = $db
                } | Select-DefaultView -ExcludeProperty Database
            }
        }
    }
}