[v1] Support generated columns (#72)

* Support generated columns. Update templates to not try to update generated columns as they are non-writable

* Remove Tests table from target. It's not created by yo test

loaders/parser.go

@@ -124,6 +124,7 @@ func (s *SpannerLoaderFromDDL) ColumnList(name string) ([]*models.Column, error)
 			DataType:     c.Type.SQL(),
 			NotNull:      c.NotNull,
 			IsPrimaryKey: pk,
+			IsGenerated:  c.GeneratedExpr != nil,
 		})
 	}
 

loaders/spanner.go

@@ -234,7 +234,8 @@ func spanTableColumns(client *spanner.Client, table string) ([]*models.Column, e
 		`  WHERE ic.TABLE_SCHEMA = "" and ic.TABLE_NAME = c.TABLE_NAME ` +
 		`  AND ic.COLUMN_NAME = c.COLUMN_NAME` +
 		`  AND ic.INDEX_NAME = "PRIMARY_KEY" ` +
-		`) IS_PRIMARY_KEY ` +
+		`) IS_PRIMARY_KEY, ` +
+		`IS_GENERATED = "ALWAYS" AS IS_GENERATED ` +
 		`FROM INFORMATION_SCHEMA.COLUMNS c ` +
 		`WHERE c.TABLE_SCHEMA = "" AND c.TABLE_NAME = @table ` +
 		`ORDER BY c.ORDINAL_POSITION`
@@ -277,6 +278,9 @@ func spanTableColumns(client *spanner.Client, table string) ([]*models.Column, e
 		if err := row.ColumnByName("IS_PRIMARY_KEY", &c.IsPrimaryKey); err != nil {
 			return nil, err
 		}
+		if err := row.ColumnByName("IS_GENERATED", &c.IsGenerated); err != nil {
+			return nil, err
+		}
 
 		res = append(res, &c)
 	}

models/model.go

@@ -33,6 +33,7 @@ type Column struct {
 	DataType     string // data_type
 	NotNull      bool   // not_null
 	IsPrimaryKey bool   // is_primary_key
+	IsGenerated  bool   // is_generated
 }
 
 // Index represents an index.

templates/type.go.tpl

@@ -31,6 +31,16 @@ func {{ .Name }}Columns() []string {
 	}
 }
 
+func {{ .Name }}WritableColumns() []string {
+	return []string{
+{{- range .Fields }}
+	{{- if not .Col.IsGenerated }}
+		"{{ colname .Col }}",
+	{{- end }}
+{{- end }}
+	}
+}
+
 func ({{ $short }} *{{ .Name }}) columnsToPtrs(cols []string, customPtrs map[string]interface{}) ([]interface{}, error) {
 	ret := make([]interface{}, 0, len(cols))
 	for _, col := range cols {
@@ -111,27 +121,24 @@ func new{{ .Name }}_Decoder(cols []string) func(*spanner.Row) (*{{ .Name }}, err
 // Insert returns a Mutation to insert a row into a table. If the row already
 // exists, the write or transaction fails.
 func ({{ $short }} *{{ .Name }}) Insert(ctx context.Context) *spanner.Mutation {
-	return spanner.Insert("{{ $table }}", {{ .Name }}Columns(), []interface{}{
-		{{ fieldnames .Fields $short }},
-	})
+	values, _ := {{ $short }}.columnsToValues({{ .Name }}WritableColumns())
+	return spanner.Insert("{{ $table }}", {{ .Name }}WritableColumns(), values)
 }
 
 {{ if ne (fieldnames .Fields $short .PrimaryKeyFields) "" }}
 // Update returns a Mutation to update a row in a table. If the row does not
 // already exist, the write or transaction fails.
 func ({{ $short }} *{{ .Name }}) Update(ctx context.Context) *spanner.Mutation {
-	return spanner.Update("{{ $table }}", {{ .Name }}Columns(), []interface{}{
-		{{ fieldnames .Fields $short }},
-	})
+	values, _ := {{ $short }}.columnsToValues({{ .Name }}WritableColumns())
+	return spanner.Update("{{ $table }}", {{ .Name }}WritableColumns(), values)
 }
 
 // InsertOrUpdate returns a Mutation to insert a row into a table. If the row
 // already exists, it updates it instead. Any column values not explicitly
 // written are preserved.
 func ({{ $short }} *{{ .Name }}) InsertOrUpdate(ctx context.Context) *spanner.Mutation {
-	return spanner.InsertOrUpdate("{{ $table }}", {{ .Name }}Columns(), []interface{}{
-		{{ fieldnames .Fields $short }},
-	})
+	values, _ := {{ $short }}.columnsToValues({{ .Name }}WritableColumns())
+	return spanner.InsertOrUpdate("{{ $table }}", {{ .Name }}WritableColumns(), values)
 }
 
 // UpdateColumns returns a Mutation to update specified columns of a row in a table.

test/integration_test.go

@@ -561,6 +561,92 @@ func TestCustomCompositePrimaryKey(t *testing.T) {
 	})
 }
 
+func TestGeneratedColumn(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	gc := &models.GeneratedColumn{
+		ID:        300,
+		FirstName: "John",
+		LastName:  "Doe",
+	}
+
+	if _, err := client.Apply(ctx, []*spanner.Mutation{gc.Insert(ctx)}); err != nil {
+		t.Fatalf("Apply failed: %v", err)
+	}
+
+	t.Run("Insert", func(t *testing.T) {
+		got, err := models.FindGeneratedColumn(ctx, client.Single(), 300)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		want := &models.GeneratedColumn{
+			ID:        300,
+			FirstName: "John",
+			LastName:  "Doe",
+			FullName:  "John Doe",
+		}
+		if diff := cmp.Diff(want, got); diff != "" {
+			t.Errorf("(-got, +want)\n%s", diff)
+		}
+	})
+
+	t.Run("Update", func(t *testing.T) {
+		gc := &models.GeneratedColumn{
+			ID:        300,
+			FirstName: "Jane",
+			LastName:  "Doe",
+		}
+
+		if _, err := client.Apply(ctx, []*spanner.Mutation{gc.Update(ctx)}); err != nil {
+			t.Fatalf("Apply failed: %v", err)
+		}
+
+		got, err := models.FindGeneratedColumn(ctx, client.Single(), 300)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		want := &models.GeneratedColumn{
+			ID:        300,
+			FirstName: "Jane",
+			LastName:  "Doe",
+			FullName:  "Jane Doe",
+		}
+		if diff := cmp.Diff(want, got); diff != "" {
+			t.Errorf("(-got, +want)\n%s", diff)
+		}
+	})
+
+	t.Run("InsertOrUpdate", func(t *testing.T) {
+		gc := &models.GeneratedColumn{
+			ID:        300,
+			FirstName: "Paul",
+			LastName:  "Doe",
+		}
+
+		if _, err := client.Apply(ctx, []*spanner.Mutation{gc.InsertOrUpdate(ctx)}); err != nil {
+			t.Fatalf("Apply failed: %v", err)
+		}
+
+		got, err := models.FindGeneratedColumn(ctx, client.Single(), 300)
+		if err != nil {
+			t.Fatalf("unexpected error: %v", err)
+		}
+
+		want := &models.GeneratedColumn{
+			ID:        300,
+			FirstName: "Paul",
+			LastName:  "Doe",
+			FullName:  "Paul Doe",
+		}
+		if diff := cmp.Diff(want, got); diff != "" {
+			t.Errorf("(-got, +want)\n%s", diff)
+		}
+	})
+}
+
 func TestSessionNotFound(t *testing.T) {
 	dbName := testutil.DatabaseName(spannerProjectName, spannerInstanceName, spannerDatabaseName)
 

test/testdata/schema.sql

@@ -105,3 +105,10 @@ CREATE TABLE FereignItems (
   Category INT64 NOT NULL,
   CONSTRAINT FK_ItemID_ForeignItems FOREIGN KEY (ItemID) REFERENCES Items (ID)
 ) PRIMARY KEY (ID);
+
+CREATE TABLE GeneratedColumns (
+  ID INT64 NOT NULL,
+  FirstName STRING(50) NOT NULL,
+  LastName STRING(50) NOT NULL,
+  FullName STRING(100) NOT NULL AS (ARRAY_TO_STRING([FirstName, LastName], " ")) STORED,
+) PRIMARY KEY (ID);