functions/Get-DbaDatabase.ps1

function Get-DbaDatabase {
    <#
        .SYNOPSIS
            Gets SQL Database information for each database that is present in the target instance(s) of SQL Server.
 
        .DESCRIPTION
            The Get-DbaDatabase command gets SQL database information for each database that is present in the target instance(s) of
            SQL Server. If the name of the database is provided, the command will return only the specific database information.
 
        .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
            PSCredential object to connect as. If not specified, current Windows login will be used.
 
        .PARAMETER Database
            The database(s) to process. If unspecified, all databases will be processed.
 
        .PARAMETER ExcludeDatabase
            The database(s) to exclude.
 
        .PARAMETER ExcludeAllUserDb
            Returns only databases that are not User Databases.
            This parameter cannot be used together with -ExcludeAllSystemDb.
 
        .PARAMETER ExcludeAllSystemDb
            Returns only databases that are not System Databases.
            This parameter cannot be used together with -ExcludeAllUserDb.
 
        .PARAMETER Status
            Returns SQL Server databases in the status(es) listed.
            Could include Emergency, Online, Offline, Recovering, Restoring, Standby or Suspect.
 
        .PARAMETER Access
            Returns SQL Server databases that are Read Only or Read/Write.
            To collect both, don't use this parameter.
 
        .PARAMETER Owner
            Returns list of databases owned by the specified logins.
 
        .PARAMETER Encrypted
            Returns list of databases that have TDE enabled from the SQL Server instance(s) executed against.
 
        .PARAMETER RecoveryModel
            Returns list of databases in listed recovery models (Full, Simple or Bulk Logged).
 
        .PARAMETER NoFullBackup
            Returns databases without a full backup recorded by SQL Server. Will indicate those which only have CopyOnly full backups.
 
        .PARAMETER NoFullBackupSince
            DateTime value. Returns list of databases that haven't had a full backup since the passed in DateTime.
 
        .PARAMETER NoLogBackup
            Returns databases without a Log backup recorded by SQL Server. Will indicate those which only have CopyOnly Log backups.
 
        .PARAMETER NoLogBackupSince
            DateTime value. Returns list of databases that haven't had a Log backup since the passed in DateTime.
 
        .PARAMETER IncludeLastUsed
            Returns the Last used read and write Times for the Database using the sys.dm_db_index_usage_stats DMV which will show
            the information since the last restart of SQL
 
        .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 Silent
            Use this switch to disable any kind of verbose messages
 
        .NOTES
            Tags: Database
            Original Author: Garry Bargsley (@gbargsley | http://blog.garrybargsley.com)
            Author: Klaas Vandenberghe ( @PowerDbaKlaas )
            Author: Simone Bizzotto ( @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-DbaDatabase
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance localhost
 
            Returns all databases on the local default SQL Server instance
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance localhost -ExcludeAllUserDb
 
            Returns only the system databases on the local default SQL Server instance
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance localhost -ExcludeAllSystemDb
 
            Returns only the user databases on the local default SQL Server instance
 
        .EXAMPLE
            'localhost','sql2016' | Get-DbaDatabase
 
            Returns databases on multiple instances piped into the function
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL1\SQLExpress -RecoveryModel full,Simple
 
            Returns only the user databases in Full or Simple recovery model from SQL1\SQLExpress
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL1\SQLExpress -Status Normal
 
            Returns only the user databases with status 'normal' from sql instance SQL1\SQLExpress
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL1\SQLExpress -IncludeLastUsed
 
            Returns the databases from sql instance SQL1\SQLExpress including the last used information
            from the sys.dm_db_index_usage_stats DMV
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL1\SQLExpress,SQL2 -ExcludeDatabase model,master
 
            Returns all databases except master and model from sql instances SQL1\SQLExpress and SQL2
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL1\SQLExpress,SQL2 -Encrypted
 
            Returns only encrypted databases from sql instances SQL1\SQLExpress and SQL2
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL1\SQLExpress,SQL2 -Access ReadOnly
 
            Returns only read only databases from sql instances SQL1\SQLExpress and SQL2
 
        .EXAMPLE
            Get-DbaDatabase -SqlInstance SQL2,SQL3 -Database OneDB,OtherDB
 
            Returns databases 'OneDb' and 'OtherDB' from sql instances SQL2 and SQL3 if the databases exist on those instances
    #>

    [CmdletBinding(DefaultParameterSetName = "Default")]
    [OutputType([Microsoft.SqlServer.Management.Smo.Database[]])]
    Param (
        [parameter(Position = 0, Mandatory = $true, ValueFromPipeline = $True)]
        [Alias("ServerInstance", "SqlServer")]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [Alias("Databases")]
        [object[]]$Database,
        [object[]]$ExcludeDatabase,
        [Alias("SystemDbOnly", "NoUserDb")]
        [switch]$ExcludeAllUserDb,
        [Alias("UserDbOnly", "NoSystemDb")]
        [switch]$ExcludeAllSystemDb,
        [string[]]$Owner,
        [switch]$Encrypted,
        [ValidateSet('EmergencyMode', 'Normal', 'Offline', 'Recovering', 'Restoring', 'Standby', 'Suspect')]
        [string[]]$Status = @('EmergencyMode', 'Normal', 'Offline', 'Recovering', 'Restoring', 'Standby', 'Suspect'),
        [ValidateSet('ReadOnly', 'ReadWrite')]
        [string]$Access,
        [ValidateSet('Full', 'Simple', 'BulkLogged')]
        [string[]]$RecoveryModel = @('Full', 'Simple', 'BulkLogged'),
        [switch]$NoFullBackup,
        [datetime]$NoFullBackupSince,
        [switch]$NoLogBackup,
        [datetime]$NoLogBackupSince,
        [switch]$Silent,
        [switch]$IncludeLastUsed
    )
    
    begin {
        
        if ($ExcludeAllUserDb -and $ExcludeAllSystemDb) {
            Stop-Function -Message "You cannot specify both ExcludeAllUserDb and ExcludeAllSystemDb" -Continue -Silent $Silent
        }
        
    }
    process {
        if (Test-FunctionInterrupt) { return }
        
        foreach ($instance in $SqlInstance) {
            try {
                Write-Message -Level Verbose -Message "Connecting to $instance"
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $sqlcredential
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }
            
            if (!$IncludeLastUsed) {
                $dblastused = $null
            }
            else {
                ## Get last used information from the DMV
                $querylastused = "WITH agg AS
                (
                  SELECT
                       max(last_user_seek) last_user_seek,
                       max(last_user_scan) last_user_scan,
                       max(last_user_lookup) last_user_lookup,
                       max(last_user_update) last_user_update,
                       sd.name dbname
                   FROM
                       sys.dm_db_index_usage_stats, master..sysdatabases sd
                   WHERE
                     database_id = sd.dbid AND database_id > 4
                      group by sd.name
                )
                SELECT
                   dbname,
                   last_read = MAX(last_read),
                   last_write = MAX(last_write)
                FROM
                (
                   SELECT dbname, last_user_seek, NULL FROM agg
                   UNION ALL
                   SELECT dbname, last_user_scan, NULL FROM agg
                   UNION ALL
                   SELECT dbname, last_user_lookup, NULL FROM agg
                   UNION ALL
                   SELECT dbname, NULL, last_user_update FROM agg
                ) AS x (dbname, last_read, last_write)
                GROUP BY
                   dbname
                ORDER BY 1;"

                # put a function around this to enable Pester Testing and also to ease any future changes
                function Invoke-QueryDBlastUsed {
                    $server.Query($querylastused)
                }
                $dblastused = Invoke-QueryDBlastUsed
            }
            
            if ($ExcludeAllUserDb) {
                $DBType = @($true)
            }
            elseif ($ExcludeAllSystemDb) {
                $DBType = @($false)
            }
            else {
                $DBType = @($false, $true)
            }
            
            $Readonly = switch ($Access) { 'Readonly' { @($true) } 'ReadWrite' { @($false) }
                default { @($true, $false) } }
            $Encrypt = switch (Test-Bound $Encrypted) { $true { @($true) }
                default { @($true, $false, $null) } }
            
            $inputobject = $server.Databases |
            Where-Object {
                ($_.Name -in $Database -or !$Database) -and
                ($_.Name -notin $ExcludeDatabase -or !$ExcludeDatabase) -and
                ($_.Owner -in $Owner -or !$Owner) -and
                $_.ReadOnly -in $Readonly -and
                $_.IsSystemObject -in $DBType -and
                ((Compare-Object @($_.Status.tostring().split(',').trim()) $Status -ExcludeDifferent -IncludeEqual).inputobject.count -ge 1 -or !$status) -and
                $_.RecoveryModel -in $RecoveryModel -and
                $_.EncryptionEnabled -in $Encrypt
            }
            
            if ($NoFullBackup -or $NoFullBackupSince) {
                $dabs = (Get-DbaBackupHistory -SqlInstance $server -LastFull -IgnoreCopyOnly)
                if ($null -ne $NoFullBackupSince) {
                    $dabsWithinScope = ($dabs | Where-Object End -lt $NoFullBackupSince)
                    
                    $inputobject = $inputobject | Where-Object { $_.Name -in $dabsWithinScope.Database -and $_.Name -ne 'tempdb' }
                }
                else {
                    $inputObject = $inputObject | Where-Object { $_.Name -notin $dabs.Database -and $_.Name -ne 'tempdb' }
                }
                
            }
            if ($NoLogBackup -or $NoLogBackupSince) {
                $dabs = (Get-DbaBackupHistory -SqlInstance $server -LastLog -IgnoreCopyOnly)
                if ($null -ne $NoLogBackupSince) {
                    $dabsWithinScope = ($dabs | Where-Object End -lt $NoLogBackupSince)
                    $inputobject = $inputobject |
                    Where-Object { $_.Name -in $dabsWithinScope.Database -and $_.Name -ne 'tempdb' -and $_.RecoveryModel -ne 'Simple' }
                }
                else {
                    $inputobject = $inputObject |
                    Where-Object { $_.Name -notin $dabs.Database -and $_.Name -ne 'tempdb' -and $_.RecoveryModel -ne 'Simple' }
                }
            }
            
            $defaults = 'ComputerName', 'InstanceName', 'SqlInstance', 'Name', 'Status', 'IsAccessible', 'RecoveryModel',
            'LogReuseWaitStatus', 'Size as SizeMB', 'CompatibilityLevel as Compatibility', 'Collation', 'Owner',
            'LastBackupDate as LastFullBackup', 'LastDifferentialBackupDate as LastDiffBackup',
            'LastLogBackupDate as LastLogBackup'
            
            if ($NoFullBackup -or $NoFullBackupSince -or $NoLogBackup -or $NoLogBackupSince) {
                $defaults += ('Notes')
            }
            if ($IncludeLastUsed) {
                # Add Last Used to the default view
                $defaults += ('LastRead as LastIndexRead', 'LastWrite as LastIndexWrite')
            }
            
            try {
                foreach ($db in $inputobject) {
                    
                    $Notes = $null
                    if ($NoFullBackup -or $NoFullBackupSince) {
                        if (@($db.EnumBackupSets()).count -eq @($db.EnumBackupSets() | Where-Object { $_.IsCopyOnly }).count -and (@($db.EnumBackupSets()).count -gt 0)) {
                            $Notes = "Only CopyOnly backups"
                        }
                    }
                    
                    $lastusedinfo = $dblastused | Where-Object { $_.dbname -eq $db.name }
                    Add-Member -Force -InputObject $db -MemberType NoteProperty BackupStatus -value $Notes
                    Add-Member -Force -InputObject $db -MemberType NoteProperty -Name ComputerName -value $server.NetName
                    Add-Member -Force -InputObject $db -MemberType NoteProperty -Name InstanceName -value $server.ServiceName
                    Add-Member -Force -InputObject $db -MemberType NoteProperty -Name SqlInstance -value $server.DomainInstanceName
                    Add-Member -Force -InputObject $db -MemberType NoteProperty -Name LastRead -value $lastusedinfo.last_read
                    Add-Member -Force -InputObject $db -MemberType NoteProperty -Name LastWrite -value $lastusedinfo.last_write
                    Select-DefaultView -InputObject $db -Property $defaults
                }
            }
            catch {
                Stop-Message -ErrorRecord $_ -Target $instance -Message "Failure. Collection may have been modified. If so, please use parens (Get-DbaDatabase ....) | when working with commands that modify the collection such as Remove-DbaDatabase" -Continue
            }
        }
    }
}