feat(spanner/spansql): add support for ALTER INDEX statement

spanner/spansql/parser.go

@@ -1053,6 +1053,9 @@ func (p *parser) parseDDLStmt() (DDLStmt, *parseError) {
  } else if p.sniff("ALTER", "STATISTICS") {
  as, err := p.parseAlterStatistics()
  return as, err
+ } else if p.sniff("ALTER", "INDEX") {
+ ai, err := p.parseAlterIndex()
+ return ai, err
  }
 
  return nil, p.errorf("unknown DDL statement")
@@ -2321,6 +2324,52 @@ func (p *parser) parseStatisticsOptions() (StatisticsOptions, *parseError) {
  return opts, nil
 }
 
+func (p *parser) parseAlterIndex() (*AlterIndex, *parseError) {
+ debugf("parseAlterIndex: %v", p)
+
+ if err := p.expect("ALTER"); err != nil {
+ return nil, err
+ }
+ pos := p.Pos()
+ if err := p.expect("INDEX"); err != nil {
+ return nil, err
+ }
+ iname, err := p.parseTableOrIndexOrColumnName()
+ if err != nil {
+ return nil, err
+ }
+
+ a := &AlterIndex{Name: iname, Position: pos}
+ tok := p.next()
+ if tok.err != nil {
+ return nil, tok.err
+ }
+ switch {
+ case tok.caseEqual("ADD"):
+ if err := p.expect("STORED", "COLUMN"); err != nil {
+ return nil, err
+ }
+ cname, err := p.parseTableOrIndexOrColumnName()
+ if err != nil {
+ return nil, err
+ }
+ a.Alteration = AddStoredColumn{Name: cname}
+ return a, nil
+ case tok.caseEqual("DROP"):
+ if err := p.expect("STORED", "COLUMN"); err != nil {
+ return nil, err
+ }
+ cname, err := p.parseTableOrIndexOrColumnName()
+ if err != nil {
+ return nil, err
+ }
+ a.Alteration = DropStoredColumn{Name: cname}
+ return a, nil
+ }
+
+ return nil, p.errorf("got %q, expected ADD or DROP", tok.value)
+}
+
 var baseTypes = map[string]TypeBase{
  "BOOL": Bool,
  "INT64": Int64,

spanner/spansql/parser_test.go

@@ -668,6 +668,9 @@ func TestParseDDL(t *testing.T) {
  ALTER TABLE DefaultCol ALTER COLUMN Age SET DEFAULT (0);
  ALTER TABLE DefaultCol ALTER COLUMN Age STRING(MAX) DEFAULT ("0");
 
+ ALTER INDEX MyFirstIndex ADD STORED COLUMN UpdatedAt;
+ ALTER INDEX MyFirstIndex DROP STORED COLUMN UpdatedAt;
+
  -- Trailing comment at end of file.
  `, &DDL{Filename: "filename", List: []DDLStmt{
  &CreateTable{
@@ -954,6 +957,16 @@ func TestParseDDL(t *testing.T) {
  },
  Position: line(83),
  },
+ &AlterIndex{
+ Name: "MyFirstIndex",
+ Alteration: AddStoredColumn{Name: "UpdatedAt"},
+ Position: line(85),
+ },
+ &AlterIndex{
+ Name: "MyFirstIndex",
+ Alteration: DropStoredColumn{Name: "UpdatedAt"},
+ Position: line(86),
+ },
  }, Comments: []*Comment{
  {
  Marker: "#", Start: line(2), End: line(2),
@@ -989,7 +1002,7 @@ func TestParseDDL(t *testing.T) {
  {Marker: "--", Isolated: true, Start: line(75), End: line(75), Text: []string{"Table has a column with a default value."}},
 
  // Comment after everything else.
- {Marker: "--", Isolated: true, Start: line(85), End: line(85), Text: []string{"Trailing comment at end of file."}},
+ {Marker: "--", Isolated: true, Start: line(88), End: line(88), Text: []string{"Trailing comment at end of file."}},
  }}},
  // No trailing comma:
  {`ALTER TABLE T ADD COLUMN C2 INT64`, &DDL{Filename: "filename", List: []DDLStmt{

spanner/spansql/sql.go

@@ -339,6 +339,18 @@ func (sa StatisticsOptions) SQL() string {
  return str
 }
 
+func (ai AlterIndex) SQL() string {
+ return "ALTER INDEX " + ai.Name.SQL() + " " + ai.Alteration.SQL()
+}
+
+func (asc AddStoredColumn) SQL() string {
+ return "ADD STORED COLUMN " + asc.Name.SQL()
+}
+
+func (dsc DropStoredColumn) SQL() string {
+ return "DROP STORED COLUMN " + dsc.Name.SQL()
+}
+
 func (d *Delete) SQL() string {
  return "DELETE FROM " + d.Table.SQL() + " WHERE " + d.Where.SQL()
 }

spanner/spansql/sql_test.go

@@ -466,6 +466,28 @@ func TestSQL(t *testing.T) {
  "ALTER STATISTICS auto_20191128_14_47_22UTC SET OPTIONS (allow_gc=false)",
  reparseDDL,
  },
+ {
+ &AlterIndex{
+ Name: "iname",
+ Alteration: AddStoredColumn{
+ Name: "cname",
+ },
+ Position: line(1),
+ },
+ "ALTER INDEX iname ADD STORED COLUMN cname",
+ reparseDDL,
+ },
+ {
+ &AlterIndex{
+ Name: "iname",
+ Alteration: DropStoredColumn{
+ Name: "cname",
+ },
+ Position: line(1),
+ },
+ "ALTER INDEX iname DROP STORED COLUMN cname",
+ reparseDDL,
+ },
  {
  &Insert{
  Table: "Singers",

spanner/spansql/types.go

@@ -1146,3 +1146,28 @@ func (SetStatisticsOptions) isStatisticsAlteration() {}
 type StatisticsOptions struct {
  AllowGC *bool
 }
+
+type AlterIndex struct {
+ Name ID
+ Alteration IndexAlteration
+
+ Position Position // position of the "ALTER" token
+}
+
+func (as *AlterIndex) String() string { return fmt.Sprintf("%#v", as) }
+func (*AlterIndex) isDDLStmt() {}
+func (as *AlterIndex) Pos() Position { return as.Position }
+func (as *AlterIndex) clearOffset() { as.Position.Offset = 0 }
+
+type IndexAlteration interface {
+ isIndexAlteration()
+ SQL() string
+}
+
+func (AddStoredColumn) isIndexAlteration() {}
+func (DropStoredColumn) isIndexAlteration() {}
+
+type (
+ AddStoredColumn struct{ Name ID }
+ DropStoredColumn struct{ Name ID }
+)