powershell foreach returns multiplied values-CodePudding

I am trying to exclude a list of database names got from a csv file in a foreach loop. Instead of excluding me the names of dbs powershell multiplies me the number of entries:

PS:

$b1 = Import-CSV -Path C:\tst.csv
foreach ($ServerName in $Servers){
Foreach($Database in $SQLServer.Databases)
{


foreach($a in $b1){
  $server = $a.Name
  $db = $a.SQL
 
  if ($ServerName.Name -ne $server -and $Database.Name -ne $db){
    $Database.Name  
  }
}
}
}

CSV List:

Name,SQL 
server1,db1
server1,db2
server2,db1

output:

db0
db0
db0
db1
db1
db2
db2
etc

Servers: s1 s2 s3

Can anyone give an advise on this?

Thank you!

CodePudding user response：

This condition in your inner loop:

$ServerName.Name -ne $server -and $Database.Name -ne $db

Is doing a line-by-line comparison which is likely to be $true more than once, we don't have enough information on this, but your issue is likely to be solved if you use containment operators for this (you can use -notin or -notcontains, it's up to you). As aside, your second inner loop is iterating over $SQLServer which is also not defined and unclear what it is.

$csv = Import-CSV -Path C:\tst.csv
foreach($ServerName in $Servers) {
    foreach($Database in $SQLServer.Databases) {
        if($ServerName.Name -notin $csv.Name -and $Database.Name -notin $csv.SQL) {
            $Database.Name
        }
    }
}

CodePudding user response：

add the results in an array and call it with unique paramter

to creat the array

$array = @()

in the loop add this

$array  =   $Database.Name

then after loop

$array | select -Unique