Powershell SQL SELECT output to variable

Question

I am calling a function to query an SQL table. I only need the results of one cell. I am unable to successfully retrieve the cell data into a variable from the function.

For example, If I had a table with the following:

    FeedID    Name    Address
    15        Bill    Jones

I would need to capture the FeedID value of '15' into a variable. My SQL statement is only capturing the FeedID but I don't know how to extract the value

Here is what I have so far:

    function Invoke-SQL {
    param(
    [string] $dataSource = "10.0.100.1",
    [string] $database = "Database123",
    [string] $sqlCommand = $("SELECT [FeedID] FROM [dbo].[FeedList] WHERE [FeedFileName] = 'filename.txt'")
    )

    $connectionString = "Data Source=$dataSource; " + "Integrated Security=SSPI; " + "Initial Catalog=$database"
    $connection = new-object system.data.SqlClient.SQLConnection($connectionString)
    $command = new-object system.data.sqlclient.sqlcommand($sqlCommand,$connection)
    $connection.Open()

    $adapter = New-Object System.Data.sqlclient.sqlDataAdapter $command
    $dataset = New-Object System.Data.DataSet
    write-output $adapter.Fill($dataSet) | Out-Null

    $connection.Close()
    $dataSet.Tables
    }

    $FeedID = Invoke-SQL
    $FeedID

Answer 1

Alternatively you could use the following code, if you are looking for simple return values rather than tables for processing later.

[string] $Server= "10.0.100.1",
[string] $Database = "Database123",
[string] $SQLQuery= $("SELECT [FeedID] FROM [dbo].[FeedList] WHERE [FeedFileName] = 'filename.txt'")

function GenericSqlQuery ($Server, $Database, $SQLQuery) {
    $Connection = New-Object System.Data.SQLClient.SQLConnection
    $Connection.ConnectionString = "server='$Server';database='$Database';trusted_connection=true;"
    $Connection.Open()
    $Command = New-Object System.Data.SQLClient.SQLCommand
    $Command.Connection = $Connection
    $Command.CommandText = $SQLQuery
    $Reader = $Command.ExecuteReader()
    while ($Reader.Read()) {
         $Reader.GetValue(0)
    }
    $Connection.Close()
}