Powershell SQL Database - powershell

Question

Good morning everyone. I am currently in school, working on a PowerShell project, part 2. I was able to get the script to work but now I'm being asked to do this, Check for the existence of a database named ClientDB. Output a message to the console that indicates if the database exists or if it does not. If it already exists, delete it and output a message to the console that it was deleted.Create a new database named “ClientDB” on the Microsoft SQL server instance. Output a message to the console that the database was created. Then go through the rest in creating the table and importing the csv as I've done that much. My problem is how to use the invoke-sqlcmd in an if/else, else/if statement. Thank you so much.
Try {
$DBname = "ClientDB"
$SqlServer = ".\SQLEXPRESS"
if([bool] (Get-SQLDatabase -Filter * | ? {$SqlServer -eq $DBname} ))
{ Write-Host 'ClientDB exists' }
else { Write-Host 'ClientDB does not exists' }
$CreateTableQuery = #"
use $DBname
CREATE TABLE Client_A_Contacts
(
first_name varchar(20),
last_name varchar(20),
city varchar(20),
county varchar(20),
zip varchar(20),
officePhone varchar(20),
mobilePhone varchar(20)
)
"#
Import-Module sqlps -DisableNameChecking
$ServerObject = New-Object Microsoft.SqlServer.Management.Smo.Server($SqlServer)
$DBobject = New-Object Microsoft.SqlServer.Management.Smo.Database($ServerObject, $DBname)
$DBobject.Create()
Write-Host $DBobject "create success # " $DBobject.CreateDate
Invoke-sqlcmd -ServerInstance $SqlServer -Database $DBname -Query $CreateTableQuery
Pop-Location
Import-Csv "NewClientData.csv" | ForEach-Object {Invoke-sqlcmd -ServerInstance $SqlServer -
Database $DBname -Query "insert into dbo.Client_A_Contacts values
('$($_.first_name)','$($_.last_name)','$($_.city)','$($_.county)',
'$($_.zip)','$($_.officePhone)','$($ _.mobilePhone)')"}
}
catch [System.OutOfMemoryException] {
Write-Host "Caught: System.OutOfMemoryException"
}
Invoke-Sqlcmd -Database ClientDB –ServerInstance .\SQLEXPRESS -Query ‘SELECT * FROM dbo.Client_A_Contacts’ > .\SqlResults.txt