diff --git a/deployable.go b/deployable.go
index 0969568..cf5f454 100644
--- a/deployable.go
+++ b/deployable.go
@@ -4,12 +4,14 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
-	mssql "github.com/denisenkom/go-mssqldb"
-	"github.com/pkg/errors"
-	"github.com/vippsas/sqlcode/sqlparser"
 	"io/fs"
 	"strconv"
 	"strings"
+	"time"
+
+	mssql "github.com/denisenkom/go-mssqldb"
+	"github.com/pkg/errors"
+	"github.com/vippsas/sqlcode/sqlparser"
 )
 
 type Deployable struct {
@@ -137,6 +139,8 @@ func (d *Deployable) EnsureUploaded(ctx context.Context, dbc DB) error {
 
 	lockResourceName := "sqlcode.EnsureUploaded/" + d.SchemaSuffix
 
+	// When a lock is opened with the Transaction lock owner,
+	// that lock is released when the transaction is committed or rolled back.
 	var lockRetCode int
 	err := dbc.QueryRowContext(ctx, `
 declare @retcode int;
@@ -261,3 +265,51 @@ func MustInclude(opts Options, fsys ...fs.FS) Deployable {
 	}
 	return result
 }
+
+type SchemaObject struct {
+	Name       string
+	SchemaId   int
+	Objects    int
+	CreateDate time.Time
+	ModifyDate time.Time
+}
+
+func (s *SchemaObject) Suffix() string {
+	return strings.Split(s.Name, "@")[1]
+}
+
+// Return a list of sqlcode schemas that have been uploaded to the database.
+// This includes all current and unused schemas.
+func (d *Deployable) ListUploaded(ctx context.Context, dbc DB) []*SchemaObject {
+	objects := []*SchemaObject{}
+	impersonate(ctx, dbc, "sqlcode-deploy-sandbox-user", func(conn *sql.Conn) error {
+		rows, err := conn.QueryContext(ctx, `
+		select 
+			s.name
+			, s.schema_id
+			, o.objects
+			, o.create_date
+			, o.modify_date 
+		from sys.schemas s
+		outer apply (
+			select count(o.object_id) as objects
+				, min(o.create_date) as create_date
+				, max(o.modify_date) as modify_date
+			from sys.objects o
+			where o.schema_id = s.schema_id
+		) as o
+		where s.name like 'code@%'`)
+		if err != nil {
+			return err
+		}
+
+		for rows.Next() {
+			zero := &SchemaObject{}
+			rows.Scan(&zero.Name, &zero.Objects, &zero.SchemaId, &zero.CreateDate, &zero.ModifyDate)
+			objects = append(objects, zero)
+		}
+
+		return nil
+	})
+	return objects
+}
diff --git a/docker-compose.test.yml b/docker-compose.test.yml
index c367863..94da3ec 100644
--- a/docker-compose.test.yml
+++ b/docker-compose.test.yml
@@ -3,7 +3,7 @@ services:
   # mssql
   #
   mssql:
-    image: mcr.microsoft.com/mssql/server:2022-CU18-ubuntu-22.04
+    image: mcr.microsoft.com/mssql/server:latest
 
     hostname: mssql
     container_name: mssql
diff --git a/migrations/0001.sqlcode.sql b/migrations/0001.sqlcode.sql
index 60c5c2d..dd0d047 100644
--- a/migrations/0001.sqlcode.sql
+++ b/migrations/0001.sqlcode.sql
@@ -21,6 +21,7 @@ alter role [sqlcode-deploy-role] add member [sqlcode-deploy-sandbox-user];
 -- seems fair...
 grant impersonate on user::[sqlcode-deploy-sandbox-user] to [sqlcode-deploy-role];
 
+
 go
 
 create schema sqlcode;
@@ -63,7 +64,7 @@ as begin
         declare @msg varchar(max)
         declare @sql nvarchar(max)
 
-        if @@trancount = 0 throw 55001, 'You should run sqlcode.CreateCodeSchema within a transaction', 1;
+        if @@trancount = 0 throw 55001, 'You should run sqlcode.DropCodeSchema within a transaction', 1;
 
         declare @schemaname nvarchar(max) = concat('code@', @schemasuffix)
         declare @schemaid int = (select schema_id from sys.schemas where name = @schemaname);
diff --git a/preprocess_test.go b/preprocess_test.go
index 1f81e03..bf976e8 100644
--- a/preprocess_test.go
+++ b/preprocess_test.go
@@ -1,10 +1,24 @@
 package sqlcode
 
 import (
-	"github.com/stretchr/testify/assert"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/vippsas/sqlcode/sqlparser"
 )
 
+func TestSchemaSuffixFromHash(t *testing.T) {
+	t.Run("returns a unique hash", func(t *testing.T) {
+		doc := sqlparser.Document{
+			Declares: []sqlparser.Declare{},
+		}
+
+		value := SchemaSuffixFromHash(doc)
+		require.Equal(t, value, SchemaSuffixFromHash(doc))
+	})
+}
+
 func TestLineNumberInInput(t *testing.T) {
 
 	// Scenario:
diff --git a/sqltest/sqlcode_test.go b/sqltest/sqlcode_test.go
index 0f209df..4352eac 100644
--- a/sqltest/sqlcode_test.go
+++ b/sqltest/sqlcode_test.go
@@ -23,4 +23,9 @@ func Test_RowsAffected(t *testing.T) {
 	rowsAffected, err := res.RowsAffected()
 	require.NoError(t, err)
 	assert.Equal(t, int64(1), rowsAffected)
+
+	schemas := SQL.ListUploaded(ctx, fixture.DB)
+	require.Len(t, schemas, 1)
+	require.Equal(t, 6, schemas[0].Objects)
+	require.Equal(t, "5420c0269aaf", schemas[0].Suffix())
 }