Get All Content Databases from SQL by PowerShell

[reflection.assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo")
$sqlServer = new-object ("Microsoft.SqlServer.Management.Smo.Server") "test\testsqlserver"
foreach($sqlDatabase in $sqlServer.databases) {$sqlDatabase.name}

Get SharePoint Content Database Sizes by PowerShell

$date = Get-Date -Format "dd-MM-yyyy" 
Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
$TXTFile = "c:ReportsSPContentDatabase_$date.txt"
$webapps = Get-SPWebApplication
foreach($webapp in $webapps)
{
$ContentDatabases = $webapp.ContentDatabases
Add-Content -Path $TXTFile -Value "Content databases for $($webapp.url)"
foreach($ContentDatabase in $ContentDatabases)
{
$ContentDatabaseSize = [Math]::Round(($ContentDatabase.disksizerequired/1GB),2)
Add-Content -Path $TXTFile -Value "-     $($ContentDatabase.Name): $($ContentDatabaseSize)GB"
}
}
------------------------------------------------------------------------------------------

-Send Results By Email-

Add-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue
$date = Get-Date -Format "dd-MM-yyyy" 
$TXTFile = "c:ReportsSPContentDatabase_$date.txt"
$SMTPServer = "relay.com"
$emailFrom = "test@test.com"
$emailTo = "testto@test.com"
$subject = "Content Database size reports"
$emailBody = "Daily/Weekly/Monthly report on Content databases"

$webapps = Get-SPWebApplication
foreach($webapp in $webapps)
{
$ContentDatabases = $webapp.ContentDatabases
Add-Content -Path $TXTFile -Value "Content databases for $($webapp.url)"
foreach($ContentDatabase in $ContentDatabases)
{
$ContentDatabaseSize = [Math]::Round(($ContentDatabase.disksizerequired/1GB),2)
Add-Content -Path $TXTFile -Value "-     $($ContentDatabase.Name): $($ContentDatabaseSize)GB"
}
}
if(!($SMTPServer) -OR !($emailFrom) -OR !($emailTo))
{
Write-Host "No e-mail being sent, if you do want to send an e-mail, please enter the values for the following variables: $SMTPServer, $emailFrom and $emailTo."
}
else
{
Send-MailMessage -SmtpServer $SMTPServer -From $emailFrom -To $emailTo -Subject $subject -Body $emailBody -Attachment $TXTFile
}

Create Site Columns & Site Content Types by PowerShell

• Take care all columns Web id & Lookup Filed List id
  If you have Lookup field first create list and get id