fix(spanddl): support dropping interleaved tables

spanddl/database.go

@@ -2,6 +2,7 @@ package spanddl
 
 import (
 	"fmt"
+	"strings"
 
 	"cloud.google.com/go/spanner/spansql"
 )
@@ -118,7 +119,15 @@ func (d *Database) applyDropTable(stmt *spansql.DropTable) (err error) {
 	if i == -1 {
 		return fmt.Errorf("table %s does not exist", stmt.Name)
 	}
+	if table, ok := d.Table(stmt.Name); ok && len(table.InterleavedTables) > 0 {
+		names := make([]string, 0, len(table.InterleavedTables))
+		for _, t := range table.InterleavedTables {
+			names = append(names, string(t.Name))
+		}
+		return fmt.Errorf("table %s has interleaved tables %s", stmt.Name, strings.Join(names, ", "))
+	}
 	d.Tables = append(d.Tables[:i], d.Tables[i+1:]...)
+	d.removeInterleavedReferenceFromParentTable(stmt.Name)
 	return nil
 }
 
@@ -177,3 +186,20 @@ func (d *Database) indexOfIndex(name spansql.ID) int {
 	}
 	return -1
 }
+
+func (d *Database) removeInterleavedReferenceFromParentTable(name spansql.ID) {
+	for _, table := range d.Tables {
+		index := -1
+		for i, it := range table.InterleavedTables {
+			if it.Name == name {
+				index = i
+				break
+			}
+		}
+		if index >= 0 {
+			// Parent table found
+			table.InterleavedTables = append(table.InterleavedTables[:index], table.InterleavedTables[index+1:]...)
+			return
+		}
+	}
+}

spanddl/database_test.go

@@ -13,6 +13,7 @@ func TestDatabase_ApplyDDL(t *testing.T) {
 		name          string
 		ddls          []string
 		expected      *Database
+		errorDdlIndex int
 		errorContains string
 	}{
 		{
@@ -45,6 +46,23 @@ func TestDatabase_ApplyDDL(t *testing.T) {
 			},
 		},
 
+		{
+			name: "drop missing table",
+			ddls: []string{
+				`CREATE TABLE Singers (
+				  SingerId   INT64 NOT NULL,
+				  FirstName  STRING(1024),
+				  LastName   STRING(1024),
+				  SingerInfo BYTES(MAX),
+				  BirthDate  DATE,
+				) PRIMARY KEY(SingerId);`,
+
+				`DROP TABLE Albums`,
+			},
+			errorDdlIndex: 1,
+			errorContains: "DROP TABLE: table Albums does not exist",
+		},
+
 		{
 			name: "create table with row deletion policy",
 			ddls: []string{
@@ -274,6 +292,77 @@ func TestDatabase_ApplyDDL(t *testing.T) {
 			},
 		},
 
+		{
+			name: "drop interleaved",
+			ddls: []string{
+				`CREATE TABLE Singers (
+				  SingerId   INT64 NOT NULL,
+				  FirstName  STRING(1024),
+				  LastName   STRING(1024),
+				  SingerInfo BYTES(MAX),
+				  BirthDate  DATE,
+				) PRIMARY KEY(SingerId);`,
+
+				`CREATE TABLE Albums (
+				  SingerId     INT64 NOT NULL,
+				  AlbumId      INT64 NOT NULL,
+				  AlbumTitle   STRING(MAX),
+				) PRIMARY KEY (SingerId, AlbumId),
+				  INTERLEAVE IN PARENT Singers ON DELETE CASCADE;`,
+
+				`DROP TABLE Albums;`,
+			},
+			expected: &Database{
+				Tables: []*Table{
+					{
+						Name: "Singers",
+						Columns: []*Column{
+							{Name: "SingerId", Type: spansql.Type{Base: spansql.Int64}, NotNull: true},
+							{Name: "FirstName", Type: spansql.Type{Base: spansql.String, Len: 1024}},
+							{Name: "LastName", Type: spansql.Type{Base: spansql.String, Len: 1024}},
+							{Name: "SingerInfo", Type: spansql.Type{Base: spansql.Bytes, Len: spansql.MaxLen}},
+							{Name: "BirthDate", Type: spansql.Type{Base: spansql.Date}},
+						},
+						PrimaryKey: []spansql.KeyPart{
+							{Column: "SingerId"},
+						},
+						InterleavedTables: []*Table{},
+					},
+				},
+			},
+		},
+
+		{
+			name: "drop table with interleaved tables",
+			ddls: []string{
+				`CREATE TABLE Singers (
+				  SingerId   INT64 NOT NULL,
+				  FirstName  STRING(1024),
+				  LastName   STRING(1024),
+				  SingerInfo BYTES(MAX),
+				  BirthDate  DATE,
+				) PRIMARY KEY(SingerId);`,
+
+				`CREATE TABLE Albums (
+				  SingerId     INT64 NOT NULL,
+				  AlbumId      INT64 NOT NULL,
+				  AlbumTitle   STRING(MAX),
+				) PRIMARY KEY (SingerId, AlbumId),
+				  INTERLEAVE IN PARENT Singers ON DELETE CASCADE;`,
+
+				`CREATE TABLE Genres (
+				  SingerId     INT64 NOT NULL,
+				  GenreId      INT64 NOT NULL,
+				  GenreTitle   STRING(MAX),
+				) PRIMARY KEY (SingerId, AlbumId),
+				  INTERLEAVE IN PARENT Singers ON DELETE CASCADE;`,
+
+				`DROP TABLE Singers;`,
+			},
+			errorDdlIndex: 3,
+			errorContains: "DROP TABLE: table Singers has interleaved tables Albums, Genres",
+		},
+
 		{
 			name: "create index",
 			ddls: []string{
@@ -356,13 +445,13 @@ func TestDatabase_ApplyDDL(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 			var db Database
-			for _, ddl := range tt.ddls {
+			for i, ddl := range tt.ddls {
 				ddl, err := spansql.ParseDDL(tt.name, ddl)
 				assert.NilError(t, err)
 				err = db.ApplyDDL(ddl)
-				if tt.errorContains != "" {
+				if tt.errorDdlIndex == i && tt.errorContains != "" {
 					assert.ErrorContains(t, err, tt.errorContains)
-					break
+					return
 				}
 				assert.NilError(t, err)
 			}

testdata/migrations/music/000002_create_drop_genres.up.sql

@@ -0,0 +1,8 @@
+-- This migration should result in no schema changes.
+CREATE TABLE Genres (
+                        SingerId     INT64 NOT NULL,
+                        GenreId      INT64 NOT NULL,
+) PRIMARY KEY (SingerId, GenreId),
+  INTERLEAVE IN PARENT Singers ON DELETE CASCADE;
+
+DROP TABLE Genres;