Sample script we use at RemoteX to generate a SQL file with the database schema. We call this script each time we make a change script (migration), which will be used when setting up new DB instances rather than executing all the change scripts.

generate-createscript.ps1

param(
    [parameter(mandatory=$false)] 
	$sqlInstance = "(local)",
    [parameter(mandatory=$false)] 
	$database,
    [switch] $silent
)

$csFilePath = join-path -resolve $PSScriptRoot "Services/RESTService/Service/connectionstrings.config"
$CreateTablesSql = join-path -resolve $PSScriptRoot "Setup/SetupSkeleton/DB/Schema/CreateScripts/CreateTables.sql"
$CreateSearchTablesSql = join-path -resolve $PSScriptRoot "Setup/SetupSkeleton/DB/Schema/CreateScripts/CreateSearchTables.sql"

[Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") | out-null
[Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.Management.Sdk.Sfc") | out-null

function ScriptDatabase( [string] $sqlInstance, [string] $database, [string[]] $excludeSchema, [string[]] $includeSchema ) {
    $srv = new-object Microsoft.SqlServer.Management.Smo.Server $sqlInstance
    $db = $srv.Databases[$database]

    $scrp = new-object Microsoft.SqlServer.Management.Smo.Scripter $srv
    $scrp.Options.ScriptSchema = $true
    $scrp.Options.SchemaQualify = $true
    $scrp.Options.WithDependencies = $true
    $scrp.Options.Indexes = $true   # To include indexes
    $scrp.Options.FullTextIndexes = $true   # To include full text indexes
    $scrp.Options.DriAllConstraints = $true   # to include referential constraints in the script
    $scrp.Options.DriDefaults = $true
    $scrp.Options.AnsiPadding = $false
    $scrp.Options.ScriptBatchTerminator = $true
    $scrp.Options.ExtendedProperties = $true

    $scrp.PrefetchObjects = $true # some sources suggest this may speed things up

    $schemas = @()
    $urns = @()

    # Schemas cannot be scripted using the options above without getting an scripting error
    # We create a new options object here for that
    $schemaOptions = (new-object Microsoft.SqlServer.Management.Smo.Scripter $srv).Options
    $schemaOptions.IncludeHeaders = $false
    $schemaOptions.ScriptOwner = $true

    $db.Schemas | %{
        if (!$_.IsSystemObject -and (($excludeSchema -and $excludeSchema -notcontains $_.Name ) -or ($includeSchema -and $includeSchema -contains $_.Name)) )
        {
            $schemas += $_.Script($schemaOptions)
            if(!$silent) { Write-Host -nonewline "." }
        }
    }

    $db.Tables + $db.Views + $db.StoredProcedures + $db.UserDefinedFunctions | %{
        if (!$_.IsSystemObject -and (($excludeSchema -and $excludeSchema -notcontains $_.Schema ) -or ($includeSchema -and $includeSchema -contains $_.Schema)) )
        {
            $urns += $_.Urn
            if(!$silent) { Write-Host -nonewline "." }
        }
    }

    $builder = new-object System.Text.StringBuilder
    $schemas + $scrp.Script($urns) | %{
        $builder.AppendLine($_) | out-null
        $builder.AppendLine("GO") | out-null
    }

    return $builder.ToString()
}

function connectionstring_hash( $connectionString ) {
    $connectionString.Split(';') | %{ 
        $pair = $_.Split( '=' )
        new-object psobject -property @{ "Key" = $pair[0]; "Value" = $pair[1] }
    } | group -AsHashTable Key
}

if( !( $sqlInstance -and $database )) {
    [xml]$config = gc $csFilePath
    $csmap = connectionstring_hash $config.connectionStrings.add.connectionString
    $sqlInstance = $csmap["Data Source"].Value
    $database = $csmap["Initial Catalog"].Value
}
Write-Host -foregroundcolor yellow "Using SQL server $sqlInstance and database $database"
Write-Host "Generating $CreateTablesSql"
sc -path $CreateTablesSql -value (ScriptDatabase -sqlInstance $sqlInstance -database $database -excludeSchema "Search" )
Write-Host ""
Write-Host "Generating $CreateSearchTablesSql"
sc -path $CreateSearchTablesSql -value (ScriptDatabase -sqlInstance $sqlInstance -database $database -includeSchema "Search")
Write-Host ""