functions/Write-DbaDataTable.ps1

function Write-DbaDataTable {
    <#
        .SYNOPSIS
            Writes data to a SQL Server Table.
 
        .DESCRIPTION
            Writes a .NET DataTable to a SQL Server table using SQL Bulk Copy.
 
        .PARAMETER SqlInstance
            The SQL Server instance.
 
        .PARAMETER SqlCredential
            Allows you to login to servers using SQL Logins instead of Windows Authentication (AKA Integrated or Trusted). To use:
 
            $scred = Get-Credential, then pass $scred object to the -SqlCredential parameter.
 
            Windows Authentication will be used if SqlCredential is not specified. SQL Server does not accept Windows credentials being passed as credentials.
 
            To connect as a different Windows user, run PowerShell as that user.
 
        .PARAMETER Database
            The database to import the table into.
 
        .PARAMETER InputObject
            This is the DataTable (or datarow) to import to SQL Server.
 
        .PARAMETER Table
            The table name to import data into. You can specify a one, two, or three part table name. If you specify a one or two part name, you must also use -Database.
 
            If the table does not exist, you can use -AutoCreateTable to automatically create the table with inefficient data types.
 
        .PARAMETER Schema
            Defaults to dbo if no schema is specified.
 
        .PARAMETER BatchSize
            The BatchSize for the import defaults to 5000.
 
        .PARAMETER NotifyAfter
            Sets the option to show the notification after so many rows of import
 
        .PARAMETER AutoCreateTable
            If this switch is enabled, the table will be created if it does not already exist. The table will be created with sub-optimal data types such as nvarchar(max)
 
        .PARAMETER NoTableLock
            If this switch is enabled, a table lock (TABLOCK) will not be placed on the destination table. By default, this operation will lock the destination table while running.
 
        .PARAMETER CheckConstraints
            If this switch is enabled, the SqlBulkCopy option to process check constraints will be enabled.
             
            Per Microsoft "Check constraints while data is being inserted. By default, constraints are not checked."
 
        .PARAMETER FireTriggers
            If this switch is enabled, the SqlBulkCopy option to fire insert triggers will be enabled.
 
            Per Microsoft "When specified, cause the server to fire the insert triggers for the rows being inserted into the Database."
 
        .PARAMETER KeepIdentity
            If this switch is enabled, the SqlBulkCopy option to preserve source identity values will be enabled.
 
            Per Microsoft "Preserve source identity values. When not specified, identity values are assigned by the destination."
 
        .PARAMETER KeepNulls
            If this switch is enabled, the SqlBulkCopy option to preserve NULL values will be enabled.
 
            Per Microsoft "Preserve null values in the destination table regardless of the settings for default values. When not specified, null values are replaced by default values where applicable."
 
        .PARAMETER Truncate
            If this switch is enabled, the destination table will be truncated after prompting for confirmation.
             
        .PARAMETER BulkCopyTimeOut
            Value in seconds for the BulkCopy operations timeout. The default is 30 seconds.
 
        .PARAMETER RegularUser
            If this switch is enabled, the user connecting will be assumed to be a non-administrative user. By default, the underlying connection assumes that the user has administrative privileges.
 
            This is particularly important when connecting to a SQL Azure Database.
 
        .PARAMETER WhatIf
            If this switch is enabled, no actions are performed but informational messages will be displayed that explain what would happen if the command were to run.
 
        .PARAMETER Confirm
            If this switch is enabled, you will be prompted for confirmation before executing any operations that change state.
 
        .PARAMETER Silent
            If this switch is enabled, the internal messaging functions will be silenced.
 
        .NOTES
            Tags: DataTable, Insert
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0
 
        .LINK
            https://dbatools.io/Write-DbaDataTable
 
        .EXAMPLE
            $DataTable = Import-Csv C:\temp\customers.csv | Out-DbaDataTable
            Write-DbaDataTable -SqlInstance sql2014 -InputObject $DataTable -Table mydb.dbo.customers
 
            Performs a bulk insert of all the data in customers.csv into database mydb, schema dbo, table customers. A progress bar will be shown as rows are inserted. If the destination table does not exist, the import will be halted.
 
        .EXAMPLE
            $DataTable = Import-Csv C:\temp\customers.csv | Out-DbaDataTable
            $DataTable | Write-DbaDataTable -SqlInstance sql2014 -Table mydb.dbo.customers
 
            Performs a row by row insert of the data in customers.csv. This is significantly slower than a bulk insert and will not show a progress bar.
             
            This method is not recommended. Use -InputObject instead.
 
        .EXAMPLE
            $DataTable = Import-Csv C:\temp\customers.csv | Out-DbaDataTable
            Write-DbaDataTable -SqlInstance sql2014 -InputObject $DataTable -Table mydb.dbo.customers -AutoCreateTable
 
            Performs a bulk insert of all the data in customers.csv. If mydb.dbo.customers does not exist, it will be created with inefficient but forgiving DataTypes.
 
        .EXAMPLE
            $DataTable = Import-Csv C:\temp\customers.csv | Out-DbaDataTable
            Write-DbaDataTable -SqlInstance sql2014 -InputObject $DataTable -Table mydb.dbo.customers -Truncate
 
            Performs a bulk insert of all the data in customers.csv. Prior to importing into mydb.dbo.customers, the user is informed that the table will be truncated and asks for confirmation. The user is prompted again to perform the import.
 
        .EXAMPLE
            $DataTable = Import-Csv C:\temp\customers.csv | Out-DbaDataTable
            Write-DbaDataTable -SqlInstance sql2014 -InputObject $DataTable -Database mydb -Table customers -KeepNulls
 
            Performs a bulk insert of all the data in customers.csv into mydb.dbo.customers. Because Schema was not specified, dbo was used. NULL values in the destination table will be preserved.
 
        .EXAMPLE
            $passwd = ConvertTo-SecureString "P@ssw0rd" -AsPlainText -Force
            $AzureCredential = Mew-Object System.Management.Automation.PSCredential("AzureAccount"),$passwd)
            $DataTable = Import-Csv C:\temp\customers.csv | Out-DbaDataTable
            Write-DbaDataTable -SqlInstance AzureDB.database.windows.net -InputObject $DataTable -Database mydb -Table customers -KeepNulls -Credential $AzureCredential -RegularUser -BulkCopyTimeOut 300
 
            This performs the same operation as the previous example, but against a SQL Azure Database instance using the required credentials. The -RegularUser switch is needed to prevent trying to get administrative privilege, and we increase the BulkCopyTimeout value to cope with any latency.
 
        .EXAMPLE
            $process = Get-Process | Out-DbaDataTable
            Write-DbaDataTable -InputObject $process -SqlInstance sql2014 -Database mydb -Table myprocesses -AutoCreateTable
 
            Creates a table based on the Process object with over 60 columns, converted from PowerShell data types to SQL Server data types. After the table is created a bulk insert is performed to add process information into the table.
 
            This is an example of the type conversion in action. All process properties are converted, including special types like TimeSpan. Script properties are resolved before the type conversion starts thanks to Out-DbaDataTable.
    #>

    [CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = "High")]
    param (
        [Parameter(Position = 0, Mandatory = $true)]
        [Alias("ServerInstance", "SqlServer")]
        [ValidateNotNull()]
        [DbaInstanceParameter]$SqlInstance,
        [Parameter(Position = 1)]
        [ValidateNotNull()]
        [Alias("Credential")]
        [PSCredential]$SqlCredential,
        [Parameter(Position = 2)]
        [object]$Database,
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [Alias("DataTable")]
        [ValidateNotNull()]
        [object]$InputObject,
        [Parameter(Position = 3, Mandatory = $true)]
        [ValidateNotNullOrEmpty()]
        [string]$Table,
        [Parameter(Position = 4)]
        [ValidateNotNullOrEmpty()]
        [string]$Schema = 'dbo',
        [ValidateNotNull()]
        [int]$BatchSize = 50000,
        [ValidateNotNull()]
        [int]$NotifyAfter = 5000,
        [switch]$AutoCreateTable,
        [switch]$NoTableLock,
        [switch]$CheckConstraints,
        [switch]$FireTriggers,
        [switch]$KeepIdentity,
        [switch]$KeepNulls,
        [switch]$Truncate,
        [ValidateNotNull()]
        [int]$bulkCopyTimeOut = 5000,
        [switch]$RegularUser,
        [switch]$Silent
    )

    begin {
        if (!$Truncate) { $ConfirmPreference = "None" }

        # Getting the total rows copied is a challenge. Use SqlBulkCopyExtension.
        # http://stackoverflow.com/questions/1188384/sqlbulkcopy-row-count-when-complete

        $source = 'namespace System.Data.SqlClient {
            using Reflection;
 
            public static class SqlBulkCopyExtension
            {
                const String _rowsCopiedFieldName = "_rowsCopied";
                static FieldInfo _rowsCopiedField = null;
 
                public static int RowsCopiedCount(this SqlBulkCopy bulkCopy)
                {
                    if (_rowsCopiedField == null) _rowsCopiedField = typeof(SqlBulkCopy).GetField(_rowsCopiedFieldName, BindingFlags.NonPublic | BindingFlags.GetField | BindingFlags.Instance);
                    return (int)_rowsCopiedField.GetValue(bulkCopy);
                }
            }
        }'


        Add-Type -ReferencedAssemblies 'System.Data.dll' -TypeDefinition $source -ErrorAction SilentlyContinue

        $dotCount = ([regex]::Matches($table, "\.")).count

        if ($dotCount -lt 2 -and $Database -eq $null) {
            Stop-Function -Message "You must specify a database or fully qualified table name."
            return
        }

        if ($dotCount -eq 1) {
            $schema = $Table.Split(".")[0]
            $table = $Table.Split(".")[1]
        }

        if ($dotCount -eq 2) {
            $Database = $Table.Split(".")[0]
            $schema = $Table.Split(".")[1]
            $table = $Table.Split(".")[2]
        }

        if ($Database -match "\[.*\]") {
            $Database = ($Database -replace '\[', '') -replace '\]', ''
        }

        if ($Schema -match "\[.*\]") {
            $Schema = ($Schema -replace '\[', '') -replace '\]', ''
        }

        if ($table -match "\[.*\]") {
            $table = ($table -replace '\[', '') -replace '\]', ''
        }

        $fqtn = "[$Database].[$Schema].[$table]"

        try {
            Write-Message -Level VeryVerbose -Message "Connecting to $SqlInstance." -Target $SqlInstance
            $server = Connect-SqlInstance -SqlInstance $SqlInstance -SqlCredential $SqlCredential -RegularUser:$RegularUser
        }
        catch {
            Stop-Function -Message "Failed to process Instance $SqlInstance." -ErrorRecord $_ -Target $SqlInstance
            return
        }

        if ($server.ServerType -eq 'SqlAzureDatabase') {
            <#
                For some reasons SMO wants an initial pull when talking to Azure Sql DB
                This will throw and be caught, and then we can continue as normal.
            #>

            try {
                $null = $server.Databases
            }
            catch {
                #do nothing
            }
        }
        $db = $server.Databases | Where-Object Name -eq $Database

        if ($db -eq $null) {
            Stop-Function -Message "$Database does not exist." -Target $SqlInstance
            return
        }

        $bulkCopyOptions = @()
        $options = "TableLock", "CheckConstraints", "FireTriggers", "KeepIdentity", "KeepNulls", "Default", "Truncate"

        foreach ($option in $options) {
            $optionValue = Get-Variable $option -ValueOnly -ErrorAction SilentlyContinue
            if ($optionValue -eq $true) {
                $bulkCopyOptions += "$option"
            }
        }
        $bulkCopyOptions = $bulkCopyOptions -join " & "

        if ($truncate -eq $true) {
            if ($Pscmdlet.ShouldProcess($SqlInstance, "Truncating $fqtn")) {
                try {
                    Write-Message -Level Output -Message "Truncating $fqtn."
                    $null = $server.Databases[$Database].Query("TRUNCATE TABLE $fqtn")
                }
                catch {
                    Write-Message -Level Warning -Message "Could not truncate $fqtn. Table may not exist or may have key constraints." -ErrorRecord $_
                }
            }
        }

        $bulkCopy = New-Object Data.SqlClient.SqlBulkCopy("$($server.ConnectionContext.ConnectionString);Database=$Database")
        $bulkCopy.DestinationTableName = $fqtn
        $bulkCopy.BatchSize = $BatchSize
        $bulkCopy.NotifyAfter = $NotifyAfter
        $bulkCopy.BulkCopyTimeOut = $BulkCopyTimeOut

        $elapsed = [System.Diagnostics.Stopwatch]::StartNew()
        # Add RowCount output
        $bulkCopy.Add_SqlRowsCopied( {
                $script:totalRows = $args[1].RowsCopied
                $percent = [int](($script:totalRows / $rowCount) * 100)
                $timeTaken = [math]::Round($elapsed.Elapsed.TotalSeconds, 1)
                Write-Progress -id 1 -activity "Inserting $rowCount rows." -PercentComplete $percent -Status ([System.String]::Format("Progress: {0} rows ({1}%) in {2} seconds", $script:totalRows, $percent, $timeTaken))
            })

        $PStoSQLTypes = @{
            #PS datatype = SQL data type
            'System.Int32'    = 'int';
            'System.UInt32'   = 'bigint';
            'System.Int16'    = 'smallint';
            'System.UInt16'   = 'int';
            'System.Int64'    = 'bigint';
            'System.UInt64'   = 'decimal(20,0)';
            'System.Decimal'  = 'decimal(20,5)';
            'System.Single'   = 'bigint';
            'System.Double'   = 'float';
            'System.Byte'     = 'tinyint';
            'System.SByte'    = 'smallint';
            'System.TimeSpan' = 'nvarchar(30)';
            'System.String'   = 'nvarchar(MAX)';
            'System.Char'     = 'nvarchar(1)'
            'System.DateTime' = 'datetime2';
            'System.Boolean'  = 'bit';
            'System.Guid'     = 'uniqueidentifier';
            'Int32'           = 'int';
            'UInt32'          = 'bigint';
            'Int16'           = 'smallint';
            'UInt16'          = 'int';
            'Int64'           = 'bigint';
            'UInt64'          = 'decimal(20,0)';
            'Decimal'         = 'decimal(20,5)';
            'Single'          = 'bigint';
            'Double'          = 'float';
            'Byte'            = 'tinyint';
            'SByte'           = 'smallint';
            'TimeSpan'        = 'nvarchar(30)';
            'String'          = 'nvarchar(MAX)';
            'Char'            = 'nvarchar(1)'
            'DateTime'        = 'datetime2';
            'Boolean'         = 'bit';
            'Bool'            = 'bit';
            'Guid'            = 'uniqueidentifier';
            'int'             = 'int';
            'long'            = 'bigint';
        }
    }
    process {
        if (Test-FunctionInterrupt) { return }
        if ($InputObject -eq $null) {
            Stop-Function -Message "Input object is null."
            return
        }

        $validTypes = @([System.Data.DataSet], [System.Data.DataTable], [System.Data.DataRow], [System.Data.DataRow[]])

        if ($InputObject.GetType() -notin $validTypes) {
            Stop-Function -Message "Data is not of the right type (DbDataReader, DataTable, DataRow, or IDataReader). Tip: Try using Out-DbaDataTable to convert the object first."
            return
        }

        if ($InputObject.GetType() -eq [System.Data.DataSet]) {
            if ($InputObject.Tables -ne $null) { $InputObject = $InputObject.Tables }
        }

        $db.Tables.Refresh()
        $tableExists = $db | Where-Object { $table -in $_.Tables.Name -and $_.Tables.Schema -eq $schema }

        if ($tableExists -eq $null) {
            if ($AutoCreateTable -eq $false) {
                Stop-Function -Message "$fqtn does not exist. Use -AutoCreateTable to AutoCreate."
                return
            }
            else {
                if ($schema -notin $server.Databases[0].Schemas.Name) {
                    Stop-Function -Message "Schema does not exist."
                    return
                }

                # Get SQL datatypes by best guess on first data row
                $sqlDataTypes = @();
                $index = -1
                $columns = $InputObject.Columns

                if ($columns -eq $null) {
                    $columns = $InputObject.Table.Columns
                }

                foreach ($column in $columns) {
                    $sqlColumnName = $column.ColumnName

                    try {
                        $columnValue = $InputObject.Rows[0].$sqlColumnName
                    }
                    catch {
                        $columnValue = $InputObject.$sqlColumnName
                    }

                    if ($columnValue -eq $null) {
                        $columnValue = $InputObject.$sqlColumnName
                    }

                    <#
                        PS to SQL type conversion
                        If data type exists in hash table, use the corresponding SQL type
                        Else, fallback to nvarchar
                    #>

                    if ($PStoSQLTypes.Keys -contains $column.DataType) {
                        $sqlDataType = $PStoSQLTypes[$($column.DataType.toString())]
                    }
                    else {
                        $sqlDataType = "nvarchar(MAX)"
                    }

                    $sqlDataTypes += "[$sqlColumnName] $sqlDataType"
                }

                $sql = "BEGIN CREATE TABLE $fqtn ($($sqlDataTypes -join ' NULL,')) END"

                Write-Message -Level Debug -Message $sql

                if ($Pscmdlet.ShouldProcess($SqlInstance, "Creating table $fqtn")) {
                    try {
                        $null = $server.Databases[$Database].Query($sql)
                    }
                    catch {
                        Stop-Function -Message "The following query failed: $sql" -ErrorRecord $_
                        return
                    }
                }
            }
        }

        $rowCount = $InputObject.Rows.Count
        if ($rowCount -eq 0) {
            $rowCount = 1
        }

        if ($Pscmdlet.ShouldProcess($SqlInstance, "Writing $rowCount rows to $fqtn")) {
            $bulkCopy.WriteToServer($InputObject)
            if ($rowCount -is [int]) {
                Write-Progress -id 1 -activity "Inserting $rowCount rows" -status "Complete" -Completed
            }
        }
    }
    end {
        if ($bulkCopy) {
            $bulkCopy.Close()
            $bulkCopy.Dispose()
        }
    }
}