feat(spanner/spansql): add support for create, alter and drop change …

spanner/spannertest/db_test.go

@@ -728,3 +728,44 @@ func TestAddBackQuoteForHypen(t *testing.T) {
 		t.Errorf("Generated SQL statement incorrect.\n got %v\nwant %v", got, want)
 	}
 }
+
+func TestCreateAndManageChangeStream(t *testing.T) {
+	// Testing Create Change Stream
+	ddl, err := spansql.ParseDDL("filename", "CREATE CHANGE STREAM SingerAlbumStream FOR Singers(FirstName, LastName), Albums OPTIONS( retention_period = '36h' )")
+	if err != nil {
+		t.Fatalf("%s: Bad DDL", err)
+	}
+
+	got := ddl.List[0].SQL()
+	want := "CREATE CHANGE STREAM SingerAlbumStream FOR Singers(FirstName, LastName), Albums OPTIONS( retention_period='36h' )"
+
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("Generated SQL statement incorrect.\n got %v\nwant %v", got, want)
+	}
+
+	// Testing Alter Change Stream Options
+	ddl, err = spansql.ParseDDL("filename", "ALTER CHANGE STREAM SingerAlbumStream SET OPTIONS( retention_period = '20h' )")
+	if err != nil {
+		t.Fatalf("%s: Bad DDL", err)
+	}
+
+	got = ddl.List[0].SQL()
+	want = "ALTER CHANGE STREAM SingerAlbumStream SET OPTIONS( retention_period='20h' )"
+
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("Generated SQL statement incorrect.\n got %v\nwant %v", got, want)
+	}
+
+	// Testing Drop Change Stream Options
+	ddl, err = spansql.ParseDDL("filename", "DROP CHANGE STREAM SingerAlbumStream")
+	if err != nil {
+		t.Fatalf("%s: Bad DDL", err)
+	}
+
+	got = ddl.List[0].SQL()
+	want = "DROP CHANGE STREAM SingerAlbumStream"
+
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("Generated SQL statement incorrect.\n got %v\nwant %v", got, want)
+	}
+}

spanner/spansql/parser.go

@@ -982,7 +982,7 @@ func (p *parser) parseDDLStmt() (DDLStmt, *parseError) {
 
 	/*
 		statement:
-			{ create_database | create_table | create_index | alter_table | drop_table | drop_index }
+			{ create_database | create_table | create_index | alter_table | drop_table | drop_index | create_change_stream | alter_change_stream | drop_change_stream }
 	*/
 
 	// TODO: support create_database
@@ -1005,13 +1005,14 @@ func (p *parser) parseDDLStmt() (DDLStmt, *parseError) {
 		// DROP TABLE table_name
 		// DROP INDEX index_name
 		// DROP VIEW view_name
+		// DROP CHANGE STREAM change_stream_name
 		tok := p.next()
 		if tok.err != nil {
 			return nil, tok.err
 		}
 		switch {
 		default:
-			return nil, p.errorf("got %q, want TABLE, VIEW or INDEX", tok.value)
+			return nil, p.errorf("got %q, want TABLE, VIEW, INDEX or CHANGE", tok.value)
 		case tok.caseEqual("TABLE"):
 			name, err := p.parseTableOrIndexOrColumnName()
 			if err != nil {
@@ -1030,10 +1031,25 @@ func (p *parser) parseDDLStmt() (DDLStmt, *parseError) {
 				return nil, err
 			}
 			return &DropView{Name: name, Position: pos}, nil
+		case tok.caseEqual("CHANGE"):
+			if err := p.expect("STREAM"); err != nil {
+				return nil, err
+			}
+			name, err := p.parseTableOrIndexOrColumnName()
+			if err != nil {
+				return nil, err
+			}
+			return &DropChangeStream{Name: name, Position: pos}, nil
 		}
 	} else if p.sniff("ALTER", "DATABASE") {
 		a, err := p.parseAlterDatabase()
 		return a, err
+	} else if p.sniff("CREATE", "CHANGE", "STREAM") {
+		cs, err := p.parseCreateChangeStream()
+		return cs, err
+	} else if p.sniff("ALTER", "CHANGE", "STREAM") {
+		acs, err := p.parseAlterChangeStream()
+		return acs, err
 	}
 
 	return nil, p.errorf("unknown DDL statement")
@@ -2001,6 +2017,157 @@ func (p *parser) parseColumnNameList() ([]ID, *parseError) {
 	return list, err
 }
 
+func (p *parser) parseCreateChangeStream() (*CreateChangeStream, *parseError) {
+	debugf("parseCreateChangeStream: %v", p)
+
+	/*
+		CREATE CHANGE STREAM change_stream_name
+		    [FOR column_or_table_watching_definition[, ... ] ]
+		    [
+		        OPTIONS (
+		            retention_period = timespan,
+		            value_capture_type = type
+		        )
+		    ]
+	*/
+	if err := p.expect("CREATE"); err != nil {
+		return nil, err
+	}
+	pos := p.Pos()
+	if err := p.expect("CHANGE"); err != nil {
+		return nil, err
+	}
+	if err := p.expect("STREAM"); err != nil {
+		return nil, err
+	}
+	csname, err := p.parseTableOrIndexOrColumnName()
+	if err != nil {
+		return nil, err
+	}
+
+	if err := p.expect("FOR"); err != nil {
+		return nil, err
+	}
+
+	cs := &CreateChangeStream{Name: csname, Position: pos}
+
+	if p.eat("ALL") {
+		cs.WatchAllTables = true
+	} else {
+		for {
+			tname, err := p.parseTableOrIndexOrColumnName()
+			if err != nil {
+				return nil, err
+			}
+			pos := p.Pos()
+			wd := WatchDef{Table: tname, Position: pos}
+
+			if p.sniff("(") {
+				columns, err := p.parseColumnNameList()
+				if err != nil {
+					return nil, err
+				}
+				wd.Columns = columns
+			} else {
+				wd.WatchAllCols = true
+			}
+
+			cs.Watch = append(cs.Watch, wd)
+			if p.eat(",") {
+				continue
+			}
+			break
+		}
+	}
+
+	if p.sniff("OPTIONS") {
+		cs.Options, err = p.parseChangeStreamOptions()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return cs, nil
+}
+
+func (p *parser) parseAlterChangeStream() (*AlterChangeStream, *parseError) {
+	debugf("parseAlterChangeStream: %v", p)
+
+	if err := p.expect("ALTER"); err != nil {
+		return nil, err
+	}
+	pos := p.Pos()
+	if err := p.expect("CHANGE"); err != nil {
+		return nil, err
+	}
+	if err := p.expect("STREAM"); err != nil {
+		return nil, err
+	}
+	csname, err := p.parseTableOrIndexOrColumnName()
+	if err != nil {
+		return nil, err
+	}
+
+	acs := &AlterChangeStream{Name: csname, Position: pos}
+	if err := p.expect("SET"); err != nil {
+		return nil, err
+	}
+	// TODO: Support for altering watch
+	if p.sniff("OPTIONS") {
+		options, err := p.parseChangeStreamOptions()
+		if err != nil {
+			return nil, err
+		}
+		acs.Alteration = AlterChangeStreamOptions{Options: options}
+		return acs, nil
+	}
+	return nil, p.errorf("got %q, expected OPTIONS", p.next())
+}
+
+func (p *parser) parseChangeStreamOptions() (ChangeStreamOptions, *parseError) {
+	debugf("parseChangeStreamOptions: %v", p)
+	/*
+		options_def:
+			OPTIONS (
+									retention_period = timespan,
+									value_capture_type = type
+							) 	*/
+
+	if err := p.expect("OPTIONS"); err != nil {
+		return ChangeStreamOptions{}, err
+	}
+	if err := p.expect("("); err != nil {
+		return ChangeStreamOptions{}, err
+	}
+
+	var cso ChangeStreamOptions
+	if p.eat("retention_period", "=") {
+		tok := p.next()
+		if tok.err != nil {
+			return ChangeStreamOptions{}, tok.err
+		}
+		retentionPeriod := new(string)
+		if tok.value == "null" {
+			*retentionPeriod = ""
+		} else {
+			if tok.typ != stringToken {
+				return ChangeStreamOptions{}, p.errorf("invalid retention_period: %v", tok.value)
+			}
+			*retentionPeriod = tok.string
+		}
+		cso.RetentionPeriod = retentionPeriod
+	} else {
+		tok := p.next()
+		return ChangeStreamOptions{}, p.errorf("unknown change stream option: %v", tok.value)
+	}
+
+	if err := p.expect(")"); err != nil {
+		return ChangeStreamOptions{}, err
+	}
+
+	return cso, nil
+}
+
 var baseTypes = map[string]TypeBase{
 	"BOOL":      Bool,
 	"INT64":     Int64,

spanner/spansql/sql.go

@@ -96,6 +96,38 @@ func (cv CreateView) SQL() string {
 	return str
 }
 
+func (cs CreateChangeStream) SQL() string {
+	str := "CREATE CHANGE STREAM "
+	str += cs.Name.SQL() + " FOR "
+	if cs.WatchAllTables {
+		str += "ALL"
+	} else {
+		for i, table := range cs.Watch {
+			if i > 0 {
+				str += ", "
+			}
+			str += table.Table.SQL()
+			if !table.WatchAllCols {
+				str += "("
+				for i, c := range table.Columns {
+					if i > 0 {
+						str += ", "
+					}
+					str += c.SQL()
+				}
+				str += ")"
+			}
+		}
+	}
+	if cs.Options.RetentionPeriod != nil {
+		str += " OPTIONS( "
+		str += fmt.Sprintf("retention_period='%s'", *cs.Options.RetentionPeriod)
+		str += " )"
+	}
+
+	return str
+}
+
 func (dt DropTable) SQL() string {
 	return "DROP TABLE " + dt.Name.SQL()
 }
@@ -108,6 +140,18 @@ func (dv DropView) SQL() string {
 	return "DROP VIEW " + dv.Name.SQL()
 }
 
+func (dc DropChangeStream) SQL() string {
+	return "DROP CHANGE STREAM " + dc.Name.SQL()
+}
+
+func (acs AlterChangeStream) SQL() string {
+	return "ALTER CHANGE STREAM " + acs.Name.SQL() + " SET " + acs.Alteration.SQL()
+}
+
+func (ao AlterChangeStreamOptions) SQL() string {
+	return "OPTIONS( " + fmt.Sprintf("retention_period='%s'", *ao.Options.RetentionPeriod) + " )"
+}
+
 func (at AlterTable) SQL() string {
 	return "ALTER TABLE " + at.Name.SQL() + " " + at.Alteration.SQL()
 }

spanner/spansql/types.go

@@ -1030,3 +1030,80 @@ func getInlineComment(stmts statements, n Node) *Comment {
 	}
 	return c
 }
+
+// CreateChangeStream represents a CREATE CHANGE STREAM statement.
+// https://cloud.google.com/spanner/docs/change-streams/manage
+type CreateChangeStream struct {
+	Name           ID
+	Watch          []WatchDef
+	WatchAllTables bool
+	Options        ChangeStreamOptions
+
+	Position Position
+}
+
+func (cs *CreateChangeStream) String() string { return fmt.Sprintf("%#v", cs) }
+func (*CreateChangeStream) isDDLStmt()        {}
+func (cs *CreateChangeStream) Pos() Position  { return cs.Position }
+func (cs *CreateChangeStream) clearOffset() {
+	for i := range cs.Watch {
+		// Mutate in place.
+		cs.Watch[i].clearOffset()
+	}
+	cs.Position.Offset = 0
+}
+
+// AlterChangeStream represents a ALTER CHANGE STREAM statement.
+type AlterChangeStream struct {
+	Name       ID
+	Alteration ChangeStreamAlteration
+
+	Position Position
+}
+
+func (acs *AlterChangeStream) String() string { return fmt.Sprintf("%#v", acs) }
+func (*AlterChangeStream) isDDLStmt()         {}
+func (acs *AlterChangeStream) Pos() Position  { return acs.Position }
+func (acs *AlterChangeStream) clearOffset() {
+	acs.Position.Offset = 0
+}
+
+type ChangeStreamAlteration interface {
+	isChangeStreamAlteration()
+	SQL() string
+}
+
+func (AlterWatch) isChangeStreamAlteration()               {}
+func (AlterChangeStreamOptions) isChangeStreamAlteration() {}
+
+type (
+	AlterWatch               struct{ Watch []WatchDef }
+	AlterChangeStreamOptions struct{ Options ChangeStreamOptions }
+)
+
+// DropChangeStream represents a DROP CHANGE STREAM statement.
+type DropChangeStream struct {
+	Name ID
+
+	Position Position
+}
+
+func (dc *DropChangeStream) String() string { return fmt.Sprintf("%#v", dc) }
+func (*DropChangeStream) isDDLStmt()        {}
+func (dc *DropChangeStream) Pos() Position  { return dc.Position }
+func (dc *DropChangeStream) clearOffset()   { dc.Position.Offset = 0 }
+
+type WatchDef struct {
+	Table        ID
+	Columns      []ID
+	WatchAllCols bool
+
+	Position Position
+}
+
+func (wd WatchDef) Pos() Position { return wd.Position }
+func (wd *WatchDef) clearOffset() { wd.Position.Offset = 0 }
+
+type ChangeStreamOptions struct {
+	RetentionPeriod *string
+}