// ShowTables returns all the tables.
func (s *Server) ShowTables(session *Session, p *parser.ShowTables, args []sqlwire.Datum, resp *sqlwire.Response) error {
if p.Name == nil {
if session.Database == "" {
return errNoDatabase
}
p.Name = append(p.Name, session.Database)
}
dbID, err := s.lookupDatabase(p.Name.String())
if err != nil {
return err
}
prefix := keys.MakeNameMetadataKey(dbID, "")
sr, err := s.db.Scan(prefix, prefix.PrefixEnd(), 0)
if err != nil {
return err
}
var rows []sqlwire.Result_Row
for _, row := range sr {
name := string(bytes.TrimPrefix(row.Key, prefix))
rows = append(rows, sqlwire.Result_Row{
Values: []sqlwire.Datum{
{StringVal: &name},
},
})
}
resp.Results = []sqlwire.Result{
{
Columns: []string{"tables"},
Rows: rows,
},
}
return nil
}
// ShowIndex returns all the indexes for a table.
func (s *Server) ShowIndex(session *Session, p *parser.ShowIndex, args []sqlwire.Datum, resp *sqlwire.Response) error {
desc, err := s.getTableDesc(session.Database, p.Table)
if err != nil {
return err
}
// TODO(pmattis): This output doesn't match up with MySQL. Should it?
var rows []sqlwire.Result_Row
name := p.Table.Table()
for i, index := range desc.Indexes {
for j, col := range index.ColumnNames {
seq := int64(j + 1)
c := col
rows = append(rows, sqlwire.Result_Row{
Values: []sqlwire.Datum{
{StringVal: &name},
{StringVal: &desc.Indexes[i].Name},
{BoolVal: &desc.Indexes[i].Unique},
{IntVal: &seq},
{StringVal: &c},
},
})
}
}
resp.Results = []sqlwire.Result{
{
// TODO(pmattis): This output doesn't match up with MySQL. Should it?
Columns: []string{"Table", "Name", "Unique", "Seq", "Column"},
Rows: rows,
},
}
return nil
}
// ShowColumns of a table
func (s *Server) ShowColumns(session *Session, p *parser.ShowColumns, args []sqlwire.Datum, resp *sqlwire.Response) error {
desc, err := s.getTableDesc(session.Database, p.Table)
if err != nil {
return err
}
var rows []sqlwire.Result_Row
for i, col := range desc.Columns {
t := col.Type.SQLString()
rows = append(rows, sqlwire.Result_Row{
Values: []sqlwire.Datum{
{StringVal: &desc.Columns[i].Name},
{StringVal: &t},
{BoolVal: &desc.Columns[i].Nullable},
},
})
}
// TODO(pmattis): This output doesn't match up with MySQL. Should it?
resp.Results = []sqlwire.Result{
{
Columns: []string{"Field", "Type", "Null"},
Rows: rows,
},
}
return nil
}
func echo(sql string, resp *sqlwire.Response) {
resp.Results = []sqlwire.Result{
{
Columns: []string{"echo"},
Rows: []sqlwire.Result_Row{
{
Values: []sqlwire.Datum{
{
StringVal: &sql,
},
},
},
},
},
}
}
// ShowDatabases returns all the databases.
func (s *Server) ShowDatabases(session *Session, p *parser.ShowDatabases, args []sqlwire.Datum, resp *sqlwire.Response) error {
prefix := keys.MakeNameMetadataKey(structured.RootNamespaceID, "")
sr, err := s.db.Scan(prefix, prefix.PrefixEnd(), 0)
if err != nil {
return err
}
var rows []sqlwire.Result_Row
for _, row := range sr {
name := string(bytes.TrimPrefix(row.Key, prefix))
rows = append(rows, sqlwire.Result_Row{
Values: []sqlwire.Datum{
{StringVal: &name},
},
})
}
resp.Results = []sqlwire.Result{
{
Columns: []string{"Database"},
Rows: rows,
},
}
return nil
}
// ShowTables returns all the tables.
func (s *Server) ShowTables(p *parser.ShowTables, args []sqlwire.Datum, resp *sqlwire.Response) {
if p.Name == "" {
if s.database == "" {
resp.SetGoError(errors.New("no database specified"))
return
}
p.Name = s.database
}
dbID, err := s.lookupDatabase(p.Name)
if err != nil {
resp.SetGoError(err)
return
}
prefix := keys.MakeNameMetadataKey(dbID, "")
sr, err := s.db.Scan(prefix, prefix.PrefixEnd(), 0)
if err != nil {
resp.SetGoError(err)
return
}
var rows []sqlwire.Result_Row
for _, row := range sr {
name := string(bytes.TrimPrefix(row.Key, prefix))
rows = append(rows, sqlwire.Result_Row{
Values: []sqlwire.Datum{
{StringVal: &name},
},
})
}
resp.Results = []sqlwire.Result{
{
Columns: []string{"tables"},
Rows: rows,
},
}
}
// Select selects rows from a single table.
func (s *Server) Select(session *Session, p *parser.Select, args []sqlwire.Datum, resp *sqlwire.Response) error {
if len(p.Exprs) != 1 {
return fmt.Errorf("TODO(pmattis): unsupported select exprs: %s", p.Exprs)
}
if _, ok := p.Exprs[0].(*parser.StarExpr); !ok {
return fmt.Errorf("TODO(pmattis): unsupported select expr: %s", p.Exprs)
}
if len(p.From) != 1 {
return fmt.Errorf("TODO(pmattis): unsupported from: %s", p.From)
}
var desc *structured.TableDescriptor
{
ate, ok := p.From[0].(*parser.AliasedTableExpr)
if !ok {
return fmt.Errorf("TODO(pmattis): unsupported from: %s", p.From)
}
table, ok := ate.Expr.(parser.QualifiedName)
if !ok {
return fmt.Errorf("TODO(pmattis): unsupported from: %s", p.From)
}
var err error
desc, err = s.getTableDesc(session.Database, table)
if err != nil {
return err
}
}
// Retrieve all of the keys that start with our index key prefix.
startKey := proto.Key(encodeIndexKeyPrefix(desc.ID, desc.Indexes[0].ID))
endKey := startKey.PrefixEnd()
sr, err := s.db.Scan(startKey, endKey, 0)
if err != nil {
return err
}
// All of the columns for a particular row will be grouped together. We loop
// over the returned key/value pairs and decode the key to extract the
// columns encoded within the key and the column ID. We use the column ID to
// lookup the column and decode the value. All of these values go into a map
// keyed by column name. When the index key changes we output a row
// containing the current values.
//
// The TODOs here are too numerous to list. This is only performing a full
// table scan using the primary key.
var rows []sqlwire.Result_Row
var primaryKey []byte
vals := valMap{}
for _, kv := range sr {
if primaryKey != nil && !bytes.HasPrefix(kv.Key, primaryKey) {
if output, err := shouldOutputRow(p.Where, vals); err != nil {
return err
} else if output {
rows = append(rows, outputRow(desc.Columns, vals))
}
vals = valMap{}
}
remaining, err := decodeIndexKey(desc, desc.Indexes[0], vals, kv.Key)
if err != nil {
return err
}
primaryKey = []byte(kv.Key[:len(kv.Key)-len(remaining)])
_, colID := encoding.DecodeUvarint(remaining)
if err != nil {
return err
}
col, err := desc.FindColumnByID(uint32(colID))
if err != nil {
return err
}
vals[col.Name] = unmarshalValue(*col, kv)
if log.V(2) {
log.Infof("Scan %q -> %v", kv.Key, vals[col.Name])
}
}
if output, err := shouldOutputRow(p.Where, vals); err != nil {
return err
} else if output {
rows = append(rows, outputRow(desc.Columns, vals))
}
resp.Results = []sqlwire.Result{
{
Columns: make([]string, len(desc.Columns)),
Rows: rows,
},
}
for i, col := range desc.Columns {
resp.Results[0].Columns[i] = col.Name
}
return nil
}
