FK Actions: Handling interleaving & dropping issues correctly when dropping FKs

common/metrics/metrics.go

@@ -76,10 +76,10 @@ func getMigrationDataSchemaPatterns(conv *internal.Conv, migrationData *migratio
 		numIndexes += int32(len(table.Indexes))
 		depth := 0
 		tableId := table.Id
-		for conv.SpSchema[tableId].ParentId != "" {
+		for conv.SpSchema[tableId].ParentTable.Id != "" {
 			numInterleaves++
 			depth++
-			tableId = conv.SpSchema[tableId].ParentId
+			tableId = conv.SpSchema[tableId].ParentTable.Id
 		}
 		maxInterleaveDepth = int32(math.Max(float64(maxInterleaveDepth), float64(depth)))
 	}

common/utils/utils.go

@@ -521,11 +521,12 @@ func ReadSpannerSchema(ctx context.Context, conv *internal.Conv, client *sp.Clie
 		conv.Unexpected(fmt.Sprintf("error trying to fetch interleave table info from schema: %v", err))
 	}
 	// Assign parents if any.
+	// TODO: Assign ParentTable.OnDelete too
 	for tableName, parentName := range parentTables {
 		tableId, _ := internal.GetTableIdFromSpName(conv.SpSchema, tableName)
 		parentTableId, _ := internal.GetTableIdFromSpName(conv.SpSchema, parentName)
 		spTable := conv.SpSchema[tableId]
-		spTable.ParentId = parentTableId
+		spTable.ParentTable.Id = parentTableId
 		conv.SpSchema[tableId] = spTable
 	}
 	return nil
@@ -542,8 +543,8 @@ func CompareSchema(sessionFileConv, actualSpannerConv *internal.Conv) error {
 			return fmt.Errorf("table %v not found in the spanner database schema but found in the session file. If this table does not need to be migrated, please exclude it during the schema conversion and migration process", sessionTable.Name)
 		}
 		spannerTable := actualSpannerConv.SpSchema[spannerTableId]
-		sessionTableParentName := sessionFileConv.SpSchema[sessionTable.ParentId].Name
-		spannerTableParentName := actualSpannerConv.SpSchema[spannerTable.ParentId].Name
+		sessionTableParentName := sessionFileConv.SpSchema[sessionTable.ParentTable.Id].Name
+		spannerTableParentName := actualSpannerConv.SpSchema[spannerTable.ParentTable.Id].Name
 
 		//table names should match
 		if sessionTable.Name != spannerTable.Name {
@@ -555,6 +556,11 @@ func CompareSchema(sessionFileConv, actualSpannerConv *internal.Conv) error {
 			return fmt.Errorf("parent table name don't match: session table %v, parent session table name: %v, spanner table %v, parent spanner table name: %v", sessionTable.Name, sessionTableParentName, spannerTable.Name, spannerTableParentName)
 		}
 
+		//parent table on delete actions should match
+		if sessionTable.ParentTable.OnDelete != spannerTable.ParentTable.OnDelete {
+			return fmt.Errorf("parent table on delete actions don't match: session table %v, parent session table name: %v, spanner table %v, parent spanner table name: %v", sessionTable.Name, sessionTable.ParentTable.OnDelete, spannerTable.Name, spannerTable.ParentTable.OnDelete)
+		}
+
 		//number of columns should match
 		if len(sessionTable.ColDefs) != len(spannerTable.ColDefs) {
 			return fmt.Errorf("number of columns don't match: session table %v, spanner table %v", sessionTable.Name, spannerTable.Name)
@@ -659,4 +665,4 @@ func SetDataflowTemplatePath(path string) {
 
 func GetDataflowTemplatePath() string {
 	return dataflowTemplatePath
-}
+}

sources/spanner/infoschema.go

@@ -387,6 +387,7 @@ func (isi InfoSchemaImpl) GetIndexes(conv *internal.Conv, table common.SchemaAnd
 	return indexes, nil
 }
 
+// TODO: Extract & initialise ON DELETE action and return it (ON_DELETE_ACTION in information_schema.tables)
 func (isi InfoSchemaImpl) GetInterleaveTables() (map[string]string, error) {
 	q := `SELECT table_name, parent_table_name FROM information_schema.tables 
 	WHERE interleave_type = 'IN PARENT' AND table_type = 'BASE TABLE' AND table_schema = ''`

spanner/ddl/ast.go

@@ -282,6 +282,14 @@ type Foreignkey struct {
 	OnUpdate       string
 }
 
+// InterleavedParent encodes the following DDL definition:
+//
+//	INTERLEAVE IN PARENT parent_name ON DELETE delete_rule
+type InterleavedParent struct {
+	Id       string
+	OnDelete string
+}
+
 // PrintForeignKey unparses the foreign keys.
 func (k Foreignkey) PrintForeignKey(c Config) string {
 	var cols, referCols []string
@@ -311,7 +319,7 @@ type CreateTable struct {
 	PrimaryKeys   []IndexKey
 	ForeignKeys   []Foreignkey
 	Indexes       []CreateIndex
-	ParentId      string //if not empty, this table will be interleaved
+	ParentTable   InterleavedParent //if not empty, this table will be interleaved
 	Comment       string
 	Id            string
 }
@@ -353,14 +361,14 @@ func (ct CreateTable) PrintCreateTable(spSchema Schema, config Config) string {
 	}
 
 	var interleave string
-	if ct.ParentId != "" {
-		parent := spSchema[ct.ParentId].Name
+	if ct.ParentTable.Id != "" {
+		parent := spSchema[ct.ParentTable.Id].Name
 		if config.SpDialect == constants.DIALECT_POSTGRESQL {
 			// PG spanner only supports PRIMARY KEY() inside the CREATE TABLE()
 			// and thus INTERLEAVE follows immediately after closing brace.
-			interleave = " INTERLEAVE IN PARENT " + config.quote(parent)
+			interleave = " INTERLEAVE IN PARENT " + config.quote(parent) + " ON DELETE " + ct.ParentTable.OnDelete
 		} else {
-			interleave = ",\nINTERLEAVE IN PARENT " + config.quote(parent)
+			interleave = ",\nINTERLEAVE IN PARENT " + config.quote(parent) + " ON DELETE " + ct.ParentTable.OnDelete
 		}
 	}
 
@@ -507,14 +515,14 @@ func GetSortedTableIdsBySpName(s Schema) []string {
 		table := s[tableNameIdMap[tableName]]
 		tableQueue = tableQueue[1:]
 		parentTableExists := false
-		if table.ParentId != "" {
-			_, parentTableExists = s[table.ParentId]
+		if table.ParentTable.Id != "" {
+			_, parentTableExists = s[table.ParentTable.Id]
 		}
 
 		// Add table t if either:
 		// a) t is not interleaved in another table, or
 		// b) t is interleaved in another table and that table has already been added to the list.
-		if table.ParentId == "" || tableAdded[s[table.ParentId].Name] || !parentTableExists {
+		if table.ParentTable.Id == "" || tableAdded[s[table.ParentTable.Id].Name] || !parentTableExists {
 			sortedTableNames = append(sortedTableNames, tableName)
 			tableAdded[tableName] = true
 		} else {
@@ -578,7 +586,7 @@ func GetDDL(c Config, tableSchema Schema, sequenceSchema map[string]Sequence) []
 // CheckInterleaved checks if schema contains interleaved tables.
 func (s Schema) CheckInterleaved() bool {
 	for _, table := range s {
-		if table.ParentId != "" {
+		if table.ParentTable.Id != "" {
 			return true
 		}
 	}

spanner/ddl/ast_test.go

@@ -133,29 +133,30 @@ func TestPrintCreateTable(t *testing.T) {
 	cds["col1"] = ColumnDef{Name: "col1", T: Type{Name: Int64}, NotNull: true}
 	cds["col2"] = ColumnDef{Name: "col2", T: Type{Name: String, Len: MaxLength}, NotNull: false}
 	cds["col3"] = ColumnDef{Name: "col3", T: Type{Name: Bytes, Len: int64(42)}, NotNull: false}
+
 	t1 := CreateTable{
-		"mytable",
-		[]string{"col1", "col2", "col3"},
-		"",
-		cds,
-		[]IndexKey{{ColId: "col1", Desc: true}},
-		nil,
-		nil,
-		"",
-		"",
-		"1",
+		Name:          "mytable",
+		ColIds:        []string{"col1", "col2", "col3"},
+		ShardIdColumn: "",
+		ColDefs:       cds,
+		PrimaryKeys:   []IndexKey{{ColId: "col1", Desc: true}},
+		ForeignKeys:   nil,
+		Indexes:       nil,
+		ParentTable:   InterleavedParent{},
+		Comment:       "",
+		Id:            "1",
 	}
 	t2 := CreateTable{
-		"mytable",
-		[]string{"col1", "col2", "col3"},
-		"",
-		cds,
-		[]IndexKey{{ColId: "col1", Desc: true}},
-		nil,
-		nil,
-		"parent",
-		"",
-		"1",
+		Name:          "mytable",
+		ColIds:        []string{"col1", "col2", "col3"},
+		ShardIdColumn: "",
+		ColDefs:       cds,
+		PrimaryKeys:   []IndexKey{{ColId: "col1", Desc: true}},
+		ForeignKeys:   nil,
+		Indexes:       nil,
+		ParentTable:   InterleavedParent{Id: "par1", OnDelete: constants.FK_CASCADE},
+		Comment:       "",
+		Id:            "1",
 	}
 	tests := []struct {
 		name       string
@@ -192,7 +193,7 @@ func TestPrintCreateTable(t *testing.T) {
 				"	col2 STRING(MAX),\n" +
 				"	col3 BYTES(42),\n" +
 				") PRIMARY KEY (col1 DESC),\n" +
-				"INTERLEAVE IN PARENT ",
+				"INTERLEAVE IN PARENT  ON DELETE CASCADE",
 		},
 	}
 	for _, tc := range tests {
@@ -205,29 +206,30 @@ func TestPrintCreateTablePG(t *testing.T) {
 	cds["col1"] = ColumnDef{Name: "col1", T: Type{Name: Int64}, NotNull: true}
 	cds["col2"] = ColumnDef{Name: "col2", T: Type{Name: String, Len: MaxLength}, NotNull: false}
 	cds["col3"] = ColumnDef{Name: "col3", T: Type{Name: Bytes, Len: int64(42)}, NotNull: false}
+
 	t1 := CreateTable{
-		"mytable",
-		[]string{"col1", "col2", "col3"},
-		"",
-		cds,
-		[]IndexKey{{ColId: "col1", Desc: true}},
-		nil,
-		nil,
-		"",
-		"",
-		"1",
+		Name:          "mytable",
+		ColIds:        []string{"col1", "col2", "col3"},
+		ShardIdColumn: "",
+		ColDefs:       cds,
+		PrimaryKeys:   []IndexKey{{ColId: "col1", Desc: true}},
+		ForeignKeys:   nil,
+		Indexes:       nil,
+		ParentTable:   InterleavedParent{},
+		Comment:       "",
+		Id:            "1",
 	}
 	t2 := CreateTable{
-		"mytable",
-		[]string{"col1", "col2", "col3"},
-		"",
-		cds,
-		[]IndexKey{{ColId: "col1", Desc: true}},
-		nil,
-		nil,
-		"parent",
-		"",
-		"1",
+		Name:          "mytable",
+		ColIds:        []string{"col1", "col2", "col3"},
+		ShardIdColumn: "",
+		ColDefs:       cds,
+		PrimaryKeys:   []IndexKey{{ColId: "col1", Desc: true}},
+		ForeignKeys:   nil,
+		Indexes:       nil,
+		ParentTable:   InterleavedParent{Id: "par1", OnDelete: constants.FK_CASCADE},
+		Comment:       "",
+		Id:            "1",
 	}
 	tests := []struct {
 		name       string
@@ -266,7 +268,7 @@ func TestPrintCreateTablePG(t *testing.T) {
 				"	col2 VARCHAR(2621440),\n" +
 				"	col3 BYTEA,\n" +
 				"	PRIMARY KEY (col1 DESC)\n" +
-				") INTERLEAVE IN PARENT ",
+				") INTERLEAVE IN PARENT  ON DELETE CASCADE",
 		},
 	}
 	for _, tc := range tests {
@@ -631,7 +633,7 @@ func TestGetDDL(t *testing.T) {
 				"c9": {Name: "c", Id: "c9", T: Type{Name: Int64}},
 			},
 			PrimaryKeys: []IndexKey{{ColId: "c7"}, {ColId: "c8"}},
-			ParentId:    "t1",
+			ParentTable: InterleavedParent{Id: "t1", OnDelete: constants.FK_NO_ACTION},
 		},
 	}
 	tablesOnly := GetDDL(Config{Tables: true, ForeignKeys: false}, s, make(map[string]Sequence))
@@ -652,7 +654,7 @@ func TestGetDDL(t *testing.T) {
 			"	b INT64,\n" +
 			"	c INT64,\n" +
 			") PRIMARY KEY (a, b),\n" +
-			"INTERLEAVE IN PARENT table1",
+			"INTERLEAVE IN PARENT table1 ON DELETE NO ACTION",
 	}
 	assert.ElementsMatch(t, e, tablesOnly)
 
@@ -681,7 +683,7 @@ func TestGetDDL(t *testing.T) {
 			"	b INT64,\n" +
 			"	c INT64,\n" +
 			") PRIMARY KEY (a, b),\n" +
-			"INTERLEAVE IN PARENT table1",
+			"INTERLEAVE IN PARENT table1 ON DELETE NO ACTION",
 		"ALTER TABLE table1 ADD CONSTRAINT fk1 FOREIGN KEY (b) REFERENCES table2 (b) ON DELETE CASCADE",
 		"ALTER TABLE table2 ADD CONSTRAINT fk2 FOREIGN KEY (b, c) REFERENCES table3 (b, c) ON DELETE NO ACTION",
 	}
@@ -739,7 +741,7 @@ func TestGetPGDDL(t *testing.T) {
 				"c8": {Name: "c", Id: "c8", T: Type{Name: Int64}},
 			},
 			PrimaryKeys: []IndexKey{{ColId: "c6"}, {ColId: "c7"}},
-			ParentId:    "t1",
+			ParentTable: InterleavedParent{Id: "t1", OnDelete: constants.FK_NO_ACTION},
 		},
 	}
 	tablesOnly := GetDDL(Config{Tables: true, ForeignKeys: false, SpDialect: constants.DIALECT_POSTGRESQL}, s, make(map[string]Sequence))
@@ -762,7 +764,7 @@ func TestGetPGDDL(t *testing.T) {
 			"	b INT8,\n" +
 			"	c INT8,\n" +
 			"	PRIMARY KEY (a, b)\n" +
-			") INTERLEAVE IN PARENT table1",
+			") INTERLEAVE IN PARENT table1 ON DELETE NO ACTION",
 	}
 	assert.ElementsMatch(t, e, tablesOnly)
 
@@ -793,7 +795,7 @@ func TestGetPGDDL(t *testing.T) {
 			"	b INT8,\n" +
 			"	c INT8,\n" +
 			"	PRIMARY KEY (a, b)\n" +
-			") INTERLEAVE IN PARENT table1",
+			") INTERLEAVE IN PARENT table1 ON DELETE NO ACTION",
 		"ALTER TABLE table1 ADD CONSTRAINT fk1 FOREIGN KEY (b) REFERENCES table2 (b) ON DELETE CASCADE",
 		"ALTER TABLE table2 ADD CONSTRAINT fk2 FOREIGN KEY (b, c) REFERENCES table3 (b, c) ON DELETE NO ACTION",
 	}
@@ -846,14 +848,14 @@ func TestGetSortedTableIdsBySpName(t *testing.T) {
 					Id:   "table_id_1",
 				},
 				"table_id_2": CreateTable{
-					Name:     "Table2",
-					Id:       "table_id_2",
-					ParentId: "table_id_1",
+					Name:        "Table2",
+					Id:          "table_id_2",
+					ParentTable: InterleavedParent{Id: "table_id_1", OnDelete: constants.FK_CASCADE},
 				},
 				"table_id_3": CreateTable{
-					Name:     "Table3",
-					Id:       "table_id_3",
-					ParentId: "table_id_2",
+					Name:        "Table3",
+					Id:          "table_id_3",
+					ParentTable: InterleavedParent{Id: "table_id_2", OnDelete: constants.FK_NO_ACTION},
 				},
 			},
 			expected: []string{"table_id_1", "table_id_2", "table_id_3"},
@@ -878,9 +880,9 @@ func TestGetSortedTableIdsBySpName(t *testing.T) {
 			description: "Schema with a table having a non-existent parent",
 			schema: Schema{
 				"table_id_1": CreateTable{
-					Name:     "Table1",
-					Id:       "table_id_1",
-					ParentId: "table_id_2",
+					Name:        "Table1",
+					Id:          "table_id_1",
+					ParentTable: InterleavedParent{Id: "table_id_2", OnDelete: constants.FK_NO_ACTION},
 				},
 			},
 			expected: []string{"table_id_1"},

test_data/basic_session_file_test.json

@@ -48,7 +48,7 @@
    ],
    "ForeignKeys": null,
    "Indexes": null,
-   "ParentId": "",
+   "ParentTable": {"Id": "", "OnDelete": ""},
    "Comment": "Spanner schema for source table numbers",
    "Id": "t1"
   }

test_data/basic_sessions_file_wo_sequences_test.json

@@ -48,7 +48,7 @@
     ],
     "ForeignKeys": null,
     "Indexes": null,
-    "ParentId": "",
+    "ParentTable": {"Id": "", "OnDelete": ""},
     "Comment": "Spanner schema for source table numbers",
     "Id": "t1"
    }

test_data/mysql_interleave_session_test.json

@@ -61,7 +61,7 @@
 				}
 			],
 			"Indexes": null,
-			"ParentId": "",
+			"ParentTable": {"Id": "", "OnDelete": ""},
 			"Comment": "Spanner schema for source table cart",
 			"Id": "t46"
 		},
@@ -101,7 +101,7 @@
 			],
 			"ForeignKeys": null,
 			"Indexes": null,
-			"ParentId": "",
+			"ParentTable": {"Id": "", "OnDelete": ""},
 			"Comment": "Spanner schema for source table user",
 			"Id": "t51"
 		}