diff --git a/services/preview/sql/mgmt/2018-06-01-preview/sql/databases.go b/services/preview/sql/mgmt/2018-06-01-preview/sql/databases.go
index fc4ef2661cfd..6e99278108ed 100644
--- a/services/preview/sql/mgmt/2018-06-01-preview/sql/databases.go
+++ b/services/preview/sql/mgmt/2018-06-01-preview/sql/databases.go
@@ -48,7 +48,8 @@ func NewDatabasesClientWithBaseURI(baseURI string, subscriptionID string) Databa
 // from the Azure Resource Manager API or the portal.
 // serverName - the name of the server.
 // databaseName - the name of the database to failover.
-func (client DatabasesClient) Failover(ctx context.Context, resourceGroupName string, serverName string, databaseName string) (result DatabasesFailoverFuture, err error) {
+// replicaType - the type of replica to be failed over.
+func (client DatabasesClient) Failover(ctx context.Context, resourceGroupName string, serverName string, databaseName string, replicaType ReplicaType) (result DatabasesFailoverFuture, err error) {
 	if tracing.IsEnabled() {
 		ctx = tracing.StartSpan(ctx, fqdn+"/DatabasesClient.Failover")
 		defer func() {
@@ -59,7 +60,7 @@ func (client DatabasesClient) Failover(ctx context.Context, resourceGroupName st
 			tracing.EndSpan(ctx, sc, err)
 		}()
 	}
-	req, err := client.FailoverPreparer(ctx, resourceGroupName, serverName, databaseName)
+	req, err := client.FailoverPreparer(ctx, resourceGroupName, serverName, databaseName, replicaType)
 	if err != nil {
 		err = autorest.NewErrorWithError(err, "sql.DatabasesClient", "Failover", nil, "Failure preparing request")
 		return
@@ -75,7 +76,7 @@ func (client DatabasesClient) Failover(ctx context.Context, resourceGroupName st
 }
 
 // FailoverPreparer prepares the Failover request.
-func (client DatabasesClient) FailoverPreparer(ctx context.Context, resourceGroupName string, serverName string, databaseName string) (*http.Request, error) {
+func (client DatabasesClient) FailoverPreparer(ctx context.Context, resourceGroupName string, serverName string, databaseName string, replicaType ReplicaType) (*http.Request, error) {
 	pathParameters := map[string]interface{}{
 		"databaseName":      autorest.Encode("path", databaseName),
 		"resourceGroupName": autorest.Encode("path", resourceGroupName),
@@ -87,6 +88,9 @@ func (client DatabasesClient) FailoverPreparer(ctx context.Context, resourceGrou
 	queryParameters := map[string]interface{}{
 		"api-version": APIVersion,
 	}
+	if len(string(replicaType)) > 0 {
+		queryParameters["replicaType"] = autorest.Encode("query", replicaType)
+	}
 
 	preparer := autorest.CreatePreparer(
 		autorest.AsPost(),
diff --git a/services/preview/sql/mgmt/2018-06-01-preview/sql/models.go b/services/preview/sql/mgmt/2018-06-01-preview/sql/models.go
index 6826ef42f89c..6a41d0d53f0b 100644
--- a/services/preview/sql/mgmt/2018-06-01-preview/sql/models.go
+++ b/services/preview/sql/mgmt/2018-06-01-preview/sql/models.go
@@ -166,6 +166,21 @@ func PossibleManagedServerCreateModeValues() []ManagedServerCreateMode {
 	return []ManagedServerCreateMode{ManagedServerCreateModeDefault, ManagedServerCreateModePointInTimeRestore}
 }
 
+// ReplicaType enumerates the values for replica type.
+type ReplicaType string
+
+const (
+	// Primary ...
+	Primary ReplicaType = "Primary"
+	// ReadableSecondary ...
+	ReadableSecondary ReplicaType = "ReadableSecondary"
+)
+
+// PossibleReplicaTypeValues returns an array of possible values for the ReplicaType const type.
+func PossibleReplicaTypeValues() []ReplicaType {
+	return []ReplicaType{Primary, ReadableSecondary}
+}
+
 // SecurityAlertPolicyState enumerates the values for security alert policy state.
 type SecurityAlertPolicyState string
 
diff --git a/services/preview/sql/mgmt/2018-06-01-preview/sql/sqlapi/interfaces.go b/services/preview/sql/mgmt/2018-06-01-preview/sql/sqlapi/interfaces.go
index 141c762e5f0a..e448e7707d38 100644
--- a/services/preview/sql/mgmt/2018-06-01-preview/sql/sqlapi/interfaces.go
+++ b/services/preview/sql/mgmt/2018-06-01-preview/sql/sqlapi/interfaces.go
@@ -118,7 +118,7 @@ var _ ManagedDatabasesClientAPI = (*sql.ManagedDatabasesClient)(nil)
 
 // DatabasesClientAPI contains the set of methods on the DatabasesClient type.
 type DatabasesClientAPI interface {
-	Failover(ctx context.Context, resourceGroupName string, serverName string, databaseName string) (result sql.DatabasesFailoverFuture, err error)
+	Failover(ctx context.Context, resourceGroupName string, serverName string, databaseName string, replicaType sql.ReplicaType) (result sql.DatabasesFailoverFuture, err error)
 }
 
 var _ DatabasesClientAPI = (*sql.DatabasesClient)(nil)