Function Start-SQLDB-Query-withLogging {

  	<#
	  	.SYNOPSIS
	  	    Function will send a SQL Query to a SQL DB.

	  	.DESCRIPTION
	  	    Function will send a SQL Query to a SQL DB. If you set a read command (SELECT ...), function will return a dataset.

	  	.REQUIREMENT General
		    PowerShell V2 and Function "Write-Logfile".

		.REQUIREMENT Variables
		    DBSQLQuery, DBSQLQueryType, DBSQLConnectServer, DBSQLConnectUser, DBSQLConnectPassword, DBSQLConnectDatabase, DBSQLConnectIntegratedSecurity, DBSQLCommand, DBSQLAdapter, DBSQLConnection

        .REQUIREMENT Functions
            Write-Logfile

		.VERSION
		    Number: 1.0.1.0 / Date: 24.09.2017

	  	.PARAMETER DBSQLQuery
		    Give a Standard T-SQL Query

	  	.PARAMETER DBSQLQueryType
            Give read or write, depends on your planned action ("select" is only read, "insert" and "update" are write)

		.EXAMPLE
	  	    Func-DB-SQL-Query -DBSQLQueryType read -DBSQLQuery "SELECT * from TABLE;"

	  	.EXAMPLE
	  	    Func-DB-SQL-Query -DBSQLQueryType write -DBSQLQuery "INSERT INTO TABLE (column1,column2,column3) VALUES ('Text1', Zahl1, Zahl2) WHERE column4 = 'Text2';"

	  	.EXAMPLE
	  	    Func-DB-SQL-Query -DBSQLQueryType write -DBSQLQuery "UPDATE TABLE SET column1='Text1',column2=Zahl1,column3=Zahl2 WHERE column4 = 'Text2';"
	#>

    Param (
	
		[Parameter(Position=0,Mandatory=$False,HelpMessage='Give the SQL Servername or Server name incl. Instance name')]
		[ValidateNotNullOrEmpty()]
		[STRING]$DBSQLConnectServer=(Get-Variable -Name DBSQLConnectServer -Scope Global -ValueOnly -ErrorAction SilentlyContinue),
		
		[Parameter(Position=1,Mandatory=$False,HelpMessage='Give the database user name')]
		[ValidateNotNullOrEmpty()]
		[STRING]$DBSQLConnectUser=(Get-Variable -Name DBSQLConnectUser -Scope Global -ValueOnly -ErrorAction SilentlyContinue),
		
		[Parameter(Position=2,Mandatory=$False,HelpMessage='Give the database user password')]
		[ValidateNotNullOrEmpty()]
		[STRING]$DBSQLConnectPassword=(Get-Variable -Name DBSQLConnectPassword -Scope Global -ValueOnly -ErrorAction SilentlyContinue),		

		[Parameter(Position=3,Mandatory=$False,HelpMessage='Give the database name')]
		[ValidateNotNullOrEmpty()]
		[STRING]$DBSQLConnectDatabase=(Get-Variable -Name DBSQLConnectDatabase -Scope Global -ValueOnly -ErrorAction SilentlyContinue),

		[Parameter(Position=4,Mandatory=$False,HelpMessage='Determ if current login credentials should be used for database login ()')]
		[ValidateNotNullOrEmpty()]
		[STRING]$DBSQLConnectIntegratedSecurity=(Get-Variable -Name DBSQLConnectIntegratedSecurity -Scope Global -ValueOnly -ErrorAction SilentlyContinue),

        [Parameter(Position=5,Mandatory=$True,HelpMessage='Specify the SQL Query')]
        [ValidateNotNullOrEmpty()]
        [STRING]$DBSQLQuery,

        [Parameter(Position=6,Mandatory=$False,HelpMessage='Determ if Query was for read or write operations')]
        [ValidateSet("read","write")]
        [STRING]$DBSQLQueryType='read',

        [Parameter(Position=7,Mandatory=$False,HelpMessage=')')]
        [ValidateNotNullOrEmpty()]
        [STRING]$DBSQLErrorAction='continue'
            
    ) #end param ValueFromPipeline=$True


	IF (Get-Module -Name "Write-LogFile") {

	    Write-Logfile -LogLine ""
	    Write-Logfile -LogLine "Connecting with DB:"
	    Write-Logfile -LogLine "Server = $DBSQLConnectServer, uid=$DBSQLConnectUser, pwd=<set in ConfigFile>, Database = $DBSQLConnectDatabase, Integrated Security = $DBSQLConnectIntegratedSecurity"

        Try {

            $DBSQLConnection = New-Object System.Data.SqlClient.SqlConnection
            $DBSQLConnection.ConnectionString = "Server = $DBSQLConnectServer; uid=$DBSQLConnectUser; pwd=$DBSQLConnectPassword; Database = $DBSQLConnectDatabase; Integrated Security = $DBSQLConnectIntegratedSecurity"

            Write-Logfile -LogLine "Processing SQL Query:"
            Write-Logfile -LogLine $DBSQLQuery

            IF ($DBSQLQueryType -eq 'read') {

                Try {

                    $DBSQLCommand = New-Object System.Data.SqlClient.SqlCommand
                    $DBSQLCommand.CommandText = $DBSQLQuery
                    $DBSQLCommand.Connection = $DBSQLConnection

                    $DBSQLAdapter = New-Object System.Data.SqlClient.SqlDataAdapter
                    $DBSQLAdapter.SelectCommand = $DBSQLCommand

                    $DBSQLDataSet = New-Object System.Data.DataSet

                    $DBSQLConnection.Open()
                    $DBSQLAdapter.Fill($DBSQLDataSet)
                    $DBSQLConnection.Close()

                    Write-Logfile -Logline "SQL Query result with $($DBSQLDataSet.Tables[0].Rows.Count) row(s)."
                    #$DBSQLDataSet.Tables[0].Rows | Out-GridView

                    Return $DBSQLDataSet

                } #end try

                Catch {
    
                    Write-Logfile -LogLine "ERROR: Unable to process SQL Query (read)!"

                    IF ($ErrorAction -eq 'continue') {

                        Write-Logfile -LogLine "Program will continue, anyway."

                    } #end if

                    ELSEIF ($ErrorAction -eq 'stop') {

                        Write-Logfile -LogLine "Program will stop."
                        exit

                    } #end elseif

                    ELSE {
                    
                        Write-Logfile -LogLine "Invalid Value for Parameter DBSQLErrorAction detected."
                        Write-Logfile -LogLine "Allowed Values are 'continue' or 'stop'."
                        Write-Logfile -LogLine "Program will continue, anyway."

                    } #end else

                } #end catch

            } #end if

            ELSEIF ($DBSQLQueryType -eq 'write') {

                Try {

                    $DBSQLCommand = New-Object System.Data.SqlClient.SqlCommand
                    $DBSQLCommand.CommandText = $DBSQLQuery
                    $DBSQLCommand.Connection = $DBSQLConnection

                    $DBSQLConnection.Open()
                    $DBSQLCommand.ExecuteNonQuery()
                    $DBSQLConnection.Close()

                } #end try

                Catch {

                    Write-Logfile -LogLine "ERROR: Unable to process SQL Query (write)!"

                    IF ($ErrorAction -eq 'continue') {

                        Write-Logfile -LogLine "Program will continue, anyway."

                    } #end if

                    ELSEIF ($ErrorAction -eq 'stop') {

                        Write-Logfile -LogLine "Program will stop."
                        exit

                    } #end elseif

                    ELSE {
                    
                        Write-Logfile -LogLine "Invalid Value for parameter DBSQLErrorAction detected."
                        Write-Logfile -LogLine "Allowed Values are 'continue' or 'stop'."
                        Write-Logfile -LogLine "Program will continue, anyway."

                    } #end else

                } #end catch

            } #end elseif

            ELSE {
        
                Write-Logfile -LogLine "ERROR: Invalid parameter for function!"

            } #end else

        } #end try

        Catch {
    
            Write-Logfile -LogLine "ERROR: Unable to etablish a DB Connection!"

        } #end catch

	} #end if

	ELSE {

		Write-Host ""
		Write-Host "DEBUG Info: Write-LogFile - Module does not exist!"
		Write-Host "DEBUG Info: Please load the Module and try again, running this Function/Module!"
		Write-Host "DEBUG Info: Exiting, because of this Issue."
		EXIT	

	} #end else	

} #end function