How to use IN clause with SQLParameters? - sql

Question

My function works perfectly if I provide one instance of ComputerName value. My question is how to modify SQL query so it could accept an array? I don't believe creating a loop to query a database several times is a proper way. For example, I think this SQL query with IN clause is a proper way:
SELECT * FROM Customers WHERE Country IN ('Germany', 'France', 'UK');
In other words, I'd like to be able to call this function providing multiple ComputerName values. Like this:
PS C:\>Get-Query_Database_Query1('comp01','comp02')
The code I need help with. Please use SQLParameters to build SQL query:
function Get-Query_Database_Query1
{
[OutputType([System.Data.DataTable])]
param
(
[Parameter(Mandatory = $false,
Position = 1)]
[string]$PCname
)
#Database Query
$QueryString = "select * from [Table1] where [ComputerName]=#PCname"
#Database Connection String
$ConnectionString = 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Open\Database4.mdb;Password=;User ID=Admin'
$command = New-Object System.Data.OleDb.OleDbCommand ($QueryString, $ConnectionString)
$Command.Parameters.Add("#PCname", [System.Data.OleDb.OleDbType]::VarChar, 50).Value = $PCname;
$adapter = New-Object System.Data.OleDb.OleDbDataAdapter ($command)
#Load the Dataset
$dataset = New-Object System.Data.DataSet
[void]$adapter.Fill($dataset)
#Return the Dataset
return #( ,$dataset.Tables[0])
}

Answer 1

You need to do a little bit of string manipulation, also when working with SQL queries is a lot easier to use Here Strings.
If you are going to pass multiple computers to your functions, the parameter $PCname has to be able to accept an array of strings, hence changing [string] to [string[]].
Check out this code and see if it works for you:
function Get-Query_Database_Query1
{
[OutputType([System.Data.DataTable])]
param
(
[Parameter(Mandatory = $false,
Position = 1)]
[string[]]$PCname
)
#Database Query
$QueryString = #"
SELECT *
FROM [Table1]
WHERE [ComputerName] IN ('{0}')
"# -f ($PCname -join "','")
$QueryString
}
Get-Query_Database_Query1 -PCname 'computer1','computer2','computer3','computer4'
Here is how the query should look like:
PS /home/> Get-Query_Database_Query1 -PCname 'computer1','computer2','computer3','computer4'
SELECT *
FROM [Table1]
WHERE [ComputerName] IN ('computer1','computer2','computer3','computer4')