Golang sql.NewSession函数代码示例

// DatabaseDetails is an endpoint that returns grants and a list of table names
// for the specified database.
func (s *adminServer) DatabaseDetails(ctx context.Context, req *DatabaseDetailsRequest) (*DatabaseDetailsResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	// Placeholders don't work with SHOW statements, so we need to manually
	// escape the database name.
	//
	// TODO(cdo): Use placeholders when they're supported by SHOW.
	escDBName := parser.Name(req.Database).String()
	query := fmt.Sprintf("SHOW GRANTS ON DATABASE %s; SHOW TABLES FROM %s;", escDBName, escDBName)
	r := s.sqlExecutor.ExecuteStatements(ctx, session, query, nil)
	if pErr := s.firstNotFoundError(r.ResultList); pErr != nil {
		return nil, grpc.Errorf(codes.NotFound, "%s", pErr)
	}
	if err := s.checkQueryResults(r.ResultList, 2); err != nil {
		return nil, s.serverError(err)
	}

	// Marshal grants.
	var resp DatabaseDetailsResponse
	{
		const (
			userCol       = "User"
			privilegesCol = "Privileges"
		)

		scanner := makeResultScanner(r.ResultList[0].Columns)
		for _, row := range r.ResultList[0].Rows {
			// Marshal grant, splitting comma-separated privileges into a proper slice.
			var grant DatabaseDetailsResponse_Grant
			var privileges string
			if err := scanner.Scan(row, userCol, &grant.User); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, privilegesCol, &privileges); err != nil {
				return nil, err
			}
			grant.Privileges = strings.Split(privileges, ",")
			resp.Grants = append(resp.Grants, grant)
		}
	}

	// Marshal table names.
	{
		const tableCol = "Table"
		scanner := makeResultScanner(r.ResultList[1].Columns)
		if a, e := len(r.ResultList[1].Columns), 1; a != e {
			return nil, s.serverErrorf("show tables columns mismatch: %d != expected %d", a, e)
		}
		for _, row := range r.ResultList[1].Rows {
			var tableName string
			if err := scanner.Scan(row, tableCol, &tableName); err != nil {
				return nil, err
			}
			resp.TableNames = append(resp.TableNames, tableName)
		}
	}

	return &resp, nil
}

// Events is an endpoint that returns the latest event log entries, with the following
// optional URL parameters:
//
// type=STRING  returns events with this type (e.g. "create_table")
// targetID=INT returns events for that have this targetID
func (s *adminServer) Events(c context.Context, req *EventsRequest) (*EventsResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	// Execute the query.
	q := &sqlQuery{}
	q.Append("SELECT timestamp, eventType, targetID, reportingID, info, uniqueID ")
	q.Append("FROM system.eventlog ")
	q.Append("WHERE true ") // This simplifies the WHERE clause logic below.
	if len(req.Type) > 0 {
		q.Append("AND eventType = $ ", parser.DString(req.Type))
	}
	if req.TargetId > 0 {
		q.Append("AND targetID = $ ", parser.DInt(req.TargetId))
	}
	q.Append("ORDER BY timestamp DESC ")
	q.Append("LIMIT $", parser.DInt(apiEventLimit))
	if len(q.Errors()) > 0 {
		return nil, s.serverErrors(q.Errors())
	}
	r := s.sqlExecutor.ExecuteStatements(session, q.String(), q.Params())
	if err := s.checkQueryResults(r.ResultList, 1); err != nil {
		return nil, s.serverError(err)
	}

	// Marshal response.
	var resp EventsResponse
	scanner := newResultScanner(r.ResultList[0].Columns)
	for _, row := range r.ResultList[0].Rows {
		var event EventsResponse_Event
		var ts time.Time
		if err := scanner.ScanIndex(row, 0, &ts); err != nil {
			return nil, err
		}
		nanos := ts.UnixNano()
		event.Timestamp = &EventsResponse_Event_Timestamp{Sec: nanos / 1e9, Nsec: uint32(nanos % 1e9)}
		if err := scanner.ScanIndex(row, 1, &event.EventType); err != nil {
			return nil, err
		}
		if err := scanner.ScanIndex(row, 2, &event.TargetID); err != nil {
			return nil, err
		}
		if err := scanner.ScanIndex(row, 3, &event.ReportingID); err != nil {
			return nil, err
		}
		if err := scanner.ScanIndex(row, 4, &event.Info); err != nil {
			return nil, err
		}
		if err := scanner.ScanIndex(row, 5, &event.UniqueID); err != nil {
			return nil, err
		}

		resp.Events = append(resp.Events, &event)
	}
	return &resp, nil
}

// SetUIData is an endpoint that stores the given key/value pairs in the
// system.ui table. See GetUIData for more details on semantics.
func (s *adminServer) SetUIData(ctx context.Context, req *SetUIDataRequest) (*SetUIDataResponse, error) {
	if len(req.KeyValues) == 0 {
		return nil, grpc.Errorf(codes.InvalidArgument, "KeyValues cannot be empty")
	}

	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	for key, val := range req.KeyValues {
		// Do an upsert of the key. We update each key in a separate transaction to
		// avoid long-running transactions and possible deadlocks.
		br := s.sqlExecutor.ExecuteStatements(ctx, session, "BEGIN;", nil)
		if err := s.checkQueryResults(br.ResultList, 1); err != nil {
			return nil, s.serverError(err)
		}

		// See if the key already exists.
		resp, err := s.getUIData(session, s.getUser(req), []string{key})
		if err != nil {
			return nil, s.serverError(err)
		}
		_, alreadyExists := resp.KeyValues[key]

		// INSERT or UPDATE as appropriate.
		if alreadyExists {
			query := "UPDATE system.ui SET value = $1, lastUpdated = NOW() WHERE key = $2; COMMIT;"
			params := []parser.Datum{
				parser.DString(val), // $1
				parser.DString(key), // $2
			}
			r := s.sqlExecutor.ExecuteStatements(ctx, session, query, params)
			if err := s.checkQueryResults(r.ResultList, 2); err != nil {
				return nil, s.serverError(err)
			}
			if a, e := r.ResultList[0].RowsAffected, 1; a != e {
				return nil, s.serverErrorf("rows affected %d != expected %d", a, e)
			}
		} else {
			query := "INSERT INTO system.ui (key, value, lastUpdated) VALUES ($1, $2, NOW()); COMMIT;"
			params := []parser.Datum{
				parser.DString(key), // $1
				parser.DBytes(val),  // $2
			}
			r := s.sqlExecutor.ExecuteStatements(ctx, session, query, params)
			if err := s.checkQueryResults(r.ResultList, 2); err != nil {
				return nil, s.serverError(err)
			}
			if a, e := r.ResultList[0].RowsAffected, 1; a != e {
				return nil, s.serverErrorf("rows affected %d != expected %d", a, e)
			}
		}
	}

	return &SetUIDataResponse{}, nil
}

// SetUIData is an endpoint that sets the data associated with a key.
func (s *adminServer) SetUIData(_ context.Context, req *SetUIDataRequest) (*SetUIDataResponse, error) {
	if len(req.Key) == 0 {
		return nil, grpc.Errorf(codes.InvalidArgument, "key cannot be empty")
	}

	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	// Do an upsert of the key.
	br := s.sqlExecutor.ExecuteStatements(session, "BEGIN;", nil)
	if err := s.checkQueryResults(br.ResultList, 1); err != nil {
		return nil, s.serverError(err)
	}

	// See if the key already exists.
	alreadyExists := true
	if _, _, err := s.getUIData(session, s.getUser(req), req.Key); err != nil {
		if err != errUIKeyNotFound {
			return nil, s.serverError(err)
		}
		alreadyExists = false
	}

	// INSERT or UPDATE as appropriate.
	if alreadyExists {
		query := "UPDATE system.ui SET value = $1, lastUpdated = NOW() WHERE key = $2; COMMIT;"
		params := []parser.Datum{
			parser.DString(req.Value), // $1
			parser.DString(req.Key),   // $2
		}
		r := s.sqlExecutor.ExecuteStatements(session, query, params)
		if err := s.checkQueryResults(r.ResultList, 2); err != nil {
			return nil, s.serverError(err)
		}
		if a, e := r.ResultList[0].RowsAffected, 1; a != e {
			return nil, s.serverErrorf("rows affected %d != expected %d", a, e)
		}
	} else {
		query := "INSERT INTO system.ui (key, value, lastUpdated) VALUES ($1, $2, NOW()); COMMIT;"
		params := []parser.Datum{
			parser.DString(req.Key),  // $1
			parser.DBytes(req.Value), // $2
		}
		r := s.sqlExecutor.ExecuteStatements(session, query, params)
		if err := s.checkQueryResults(r.ResultList, 2); err != nil {
			return nil, s.serverError(err)
		}
		if a, e := r.ResultList[0].RowsAffected, 1; a != e {
			return nil, s.serverErrorf("rows affected %d != expected %d", a, e)
		}
	}

	return &SetUIDataResponse{}, nil
}

func makeV3Conn(
	conn net.Conn, executor *sql.Executor,
	metrics *serverMetrics, sessionArgs sql.SessionArgs) v3Conn {
	return v3Conn{
		conn:     conn,
		rd:       bufio.NewReader(conn),
		wr:       bufio.NewWriter(conn),
		executor: executor,
		writeBuf: writeBuffer{bytecount: metrics.bytesOutCount},
		metrics:  metrics,
		session:  sql.NewSession(sessionArgs, executor, conn.RemoteAddr()),
	}
}

// Users returns a list of users, stripped of any passwords.
func (s *adminServer) Users(ctx context.Context, req *UsersRequest) (*UsersResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)
	query := "SELECT username FROM system.users"
	r := s.sqlExecutor.ExecuteStatements(ctx, session, query, nil)
	if err := s.checkQueryResults(r.ResultList, 1); err != nil {
		return nil, s.serverError(err)
	}

	var resp UsersResponse
	for _, row := range r.ResultList[0].Rows {
		resp.Users = append(resp.Users, UsersResponse_User{string(row.Values[0].(parser.DString))})
	}
	return &resp, nil
}

// GetUIData returns data associated with the given keys, which was stored
// earlier through SetUIData.
//
// The stored values are meant to be opaque to the server. In the rare case that
// the server code needs to call this method, it should only read from keys that
// have the prefix `serverUIDataKeyPrefix`.
func (s *adminServer) GetUIData(_ context.Context, req *GetUIDataRequest) (*GetUIDataResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	if len(req.Keys) == 0 {
		return nil, grpc.Errorf(codes.InvalidArgument, "keys cannot be empty")
	}

	resp, err := s.getUIData(session, s.getUser(req), req.Keys)
	if err != nil {
		return nil, s.serverError(err)
	}

	return resp, nil
}

// GetUIData returns data associated with the given key, which was stored
// earlier through SetUIData.
func (s *adminServer) GetUIData(_ context.Context, req *GetUIDataRequest) (*GetUIDataResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	if len(req.Key) == 0 {
		return nil, grpc.Errorf(codes.InvalidArgument, "key cannot be empty")
	}

	val, ts, err := s.getUIData(session, s.getUser(req), req.Key)
	if err != nil {
		if err == errUIKeyNotFound {
			return nil, grpc.Errorf(codes.NotFound, "key %s not found", req.Key)
		}
		return nil, s.serverError(err)
	}

	return &GetUIDataResponse{Value: val, LastUpdated: &ts}, nil
}

// Databases is an endpoint that returns a list of databases.
func (s *adminServer) Databases(ctx context.Context, req *DatabasesRequest) (*DatabasesResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)
	r := s.sqlExecutor.ExecuteStatements(ctx, session, "SHOW DATABASES;", nil)
	if err := s.checkQueryResults(r.ResultList, 1); err != nil {
		return nil, s.serverError(err)
	}

	var resp DatabasesResponse
	for _, row := range r.ResultList[0].Rows {
		dbname, ok := row.Values[0].(parser.DString)
		if !ok {
			return nil, s.serverErrorf("type assertion failed on db name: %T", row.Values[0])
		}
		resp.Databases = append(resp.Databases, string(dbname))
	}

	return &resp, nil
}

func TestAdminAPIUsers(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, _, _ := serverutils.StartServer(t, base.TestServerArgs{})
	defer s.Stopper().Stop()
	ts := s.(*TestServer)

	// Create sample users.
	session := sql.NewSession(
		context.Background(), sql.SessionArgs{User: security.RootUser}, ts.sqlExecutor, nil)
	query := `
INSERT INTO system.users (username, hashedPassword)
VALUES ('admin', 'abc'), ('bob', 'xyz')`
	res := ts.sqlExecutor.ExecuteStatements(session, query, nil)
	if a, e := len(res.ResultList), 1; a != e {
		t.Fatalf("len(results) %d != %d", a, e)
	} else if res.ResultList[0].Err != nil {
		t.Fatal(res.ResultList[0].Err)
	}

	// Query the API for users.
	var resp serverpb.UsersResponse
	if err := apiGet(s, "users", &resp); err != nil {
		t.Fatal(err)
	}
	expResult := serverpb.UsersResponse{
		Users: []serverpb.UsersResponse_User{
			{Username: "admin"},
			{Username: "bob"},
		},
	}

	// Verify results.
	const sortKey = "Username"
	testutils.SortStructs(resp.Users, sortKey)
	testutils.SortStructs(expResult.Users, sortKey)
	if !reflect.DeepEqual(resp, expResult) {
		t.Fatalf("result %v != expected %v", resp, expResult)
	}
}

func TestAdminAPIEvents(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s := StartTestServer(t)
	defer s.Stop()

	session := sql.NewSession(sql.SessionArgs{User: security.RootUser}, s.sqlExecutor, nil)
	setupQueries := []string{
		"CREATE DATABASE api_test",
		"CREATE TABLE api_test.tbl1 (a INT)",
		"CREATE TABLE api_test.tbl2 (a INT)",
		"CREATE TABLE api_test.tbl3 (a INT)",
		"DROP TABLE api_test.tbl1",
		"DROP TABLE api_test.tbl2",
	}
	for _, q := range setupQueries {
		res := s.sqlExecutor.ExecuteStatements(session, q, nil)
		if res.ResultList[0].PErr != nil {
			t.Fatalf("error executing '%s': %s", q, res.ResultList[0].PErr)
		}
	}

	var zeroTimestamp EventsResponse_Event_Timestamp

	testcases := []struct {
		eventType sql.EventLogType
		expCount  int
	}{
		{"", 7},
		{sql.EventLogNodeJoin, 1},
		{sql.EventLogNodeRestart, 0},
		{sql.EventLogDropDatabase, 0},
		{sql.EventLogCreateDatabase, 1},
		{sql.EventLogDropTable, 2},
		{sql.EventLogCreateTable, 3},
	}
	for i, tc := range testcases {
		var url string
		if len(tc.eventType) > 0 {
			url = fmt.Sprintf("events?type=%s", tc.eventType)
		} else {
			url = "events"
		}
		var resp EventsResponse
		if err := apiGet(s, url, &resp); err != nil {
			t.Fatal(err)
		}

		if a, e := len(resp.Events), tc.expCount; a != e {
			t.Errorf("%d: # of events %d != expected %d", i, a, e)
		}

		// Ensure we don't have blank / nonsensical fields.
		for _, e := range resp.Events {
			if *e.Timestamp == zeroTimestamp {
				t.Errorf("%d: missing/empty timestamp", i)
			}

			if len(tc.eventType) > 0 {
				if a, e := e.EventType, string(tc.eventType); a != e {
					t.Errorf("%d: event type %s != expected %s", i, a, e)
				}
			} else {
				if len(e.EventType) == 0 {
					t.Errorf("%d: missing event type in event", i)
				}
			}

			if e.TargetID == 0 {
				t.Errorf("%d: missing/empty TargetID", i)
			}
			if e.ReportingID == 0 {
				t.Errorf("%d: missing/empty ReportingID", i)
			}
			if len(e.Info) == 0 {
				t.Errorf("%d: missing/empty Info", i)
			}
			if len(e.UniqueID) == 0 {
				t.Errorf("%d: missing/empty UniqueID", i)
			}
		}
	}
}

func TestAdminAPIDatabases(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, _, _ := serverutils.StartServer(t, base.TestServerArgs{})
	defer s.Stopper().Stop()
	ts := s.(*TestServer)

	// Test databases endpoint.
	const testdb = "test"
	session := sql.NewSession(
		context.Background(), sql.SessionArgs{User: security.RootUser}, ts.sqlExecutor, nil)
	query := "CREATE DATABASE " + testdb
	createRes := ts.sqlExecutor.ExecuteStatements(session, query, nil)
	if createRes.ResultList[0].Err != nil {
		t.Fatal(createRes.ResultList[0].Err)
	}

	var resp serverpb.DatabasesResponse
	if err := apiGet(s, "databases", &resp); err != nil {
		t.Fatal(err)
	}

	// We should have three databases:
	// - system database
	// - information_schema
	// - newly created test database
	if a, e := len(resp.Databases), 3; a != e {
		t.Fatalf("length of result %d != expected %d", a, e)
	}

	sort.Strings(resp.Databases)
	for i, e := range []string{"information_schema", "system", testdb} {
		if a := resp.Databases[i]; a != e {
			t.Fatalf("database name %s != expected %s", a, e)
		}
	}

	// Test database details endpoint.
	privileges := []string{"SELECT", "UPDATE"}
	testuser := "testuser"
	grantQuery := "GRANT " + strings.Join(privileges, ", ") + " ON DATABASE " + testdb + " TO " + testuser
	grantRes := s.(*TestServer).sqlExecutor.ExecuteStatements(session, grantQuery, nil)
	if grantRes.ResultList[0].Err != nil {
		t.Fatal(grantRes.ResultList[0].Err)
	}

	var details serverpb.DatabaseDetailsResponse
	if err := apiGet(s, "databases/"+testdb, &details); err != nil {
		t.Fatal(err)
	}

	if a, e := len(details.Grants), 2; a != e {
		t.Fatalf("# of grants %d != expected %d", a, e)
	}

	for _, grant := range details.Grants {
		switch grant.User {
		case security.RootUser:
			if !reflect.DeepEqual(grant.Privileges, []string{"ALL"}) {
				t.Fatalf("privileges %v != expected %v", details.Grants[0].Privileges, privileges)
			}
		case testuser:
			sort.Strings(grant.Privileges)
			if !reflect.DeepEqual(grant.Privileges, privileges) {
				t.Fatalf("privileges %v != expected %v", grant.Privileges, privileges)
			}
		default:
			t.Fatalf("unknown grant to user %s", grant.User)
		}
	}
}

// TableDetails is an endpoint that returns columns, indices, and other
// relevant details for the specified table.
func (s *adminServer) TableDetails(ctx context.Context, req *TableDetailsRequest) (
	*TableDetailsResponse, error) {
	session := sql.NewSession(sql.SessionArgs{User: s.getUser(req)}, s.sqlExecutor, nil)

	// TODO(cdo): Use real placeholders for the table and database names when we've extended our SQL
	// grammar to allow that.
	escDbName := parser.Name(req.Database).String()
	escTableName := parser.Name(req.Table).String()
	escQualTable := fmt.Sprintf("%s.%s", escDbName, escTableName)
	query := fmt.Sprintf("SHOW COLUMNS FROM %s; SHOW INDEX FROM %s; SHOW GRANTS ON TABLE %s",
		escQualTable, escQualTable, escQualTable)
	r := s.sqlExecutor.ExecuteStatements(ctx, session, query, nil)
	if pErr := s.firstNotFoundError(r.ResultList); pErr != nil {
		return nil, grpc.Errorf(codes.NotFound, "%s", pErr)
	}
	if err := s.checkQueryResults(r.ResultList, 3); err != nil {
		return nil, err
	}

	var resp TableDetailsResponse

	// Marshal SHOW COLUMNS result.
	//
	// TODO(cdo): protobuf v3's default behavior for fields with zero values (e.g. empty strings)
	// is to suppress them. So, if protobuf field "foo" is an empty string, "foo" won't show
	// up in the marshalled JSON. I feel that this is counterintuitive, and this should be fixed
	// for our API.
	{
		const (
			fieldCol   = "Field" // column name
			typeCol    = "Type"
			nullCol    = "Null"
			defaultCol = "Default"
		)
		scanner := makeResultScanner(r.ResultList[0].Columns)
		for _, row := range r.ResultList[0].Rows {
			var col TableDetailsResponse_Column
			if err := scanner.Scan(row, fieldCol, &col.Name); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, typeCol, &col.Type); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, nullCol, &col.Nullable); err != nil {
				return nil, err
			}
			isDefaultNull, err := scanner.IsNull(row, defaultCol)
			if err != nil {
				return nil, err
			}
			if !isDefaultNull {
				if err := scanner.Scan(row, defaultCol, &col.Default); err != nil {
					return nil, err
				}
			}
			resp.Columns = append(resp.Columns, col)
		}
	}

	// Marshal SHOW INDEX result.
	{
		const (
			nameCol      = "Name"
			uniqueCol    = "Unique"
			seqCol       = "Seq"
			columnCol    = "Column"
			directionCol = "Direction"
			storingCol   = "Storing"
		)
		scanner := makeResultScanner(r.ResultList[1].Columns)
		for _, row := range r.ResultList[1].Rows {
			// Marshal grant, splitting comma-separated privileges into a proper slice.
			var index TableDetailsResponse_Index
			if err := scanner.Scan(row, nameCol, &index.Name); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, uniqueCol, &index.Unique); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, seqCol, &index.Seq); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, columnCol, &index.Column); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, directionCol, &index.Direction); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, storingCol, &index.Storing); err != nil {
				return nil, err
			}
			resp.Indexes = append(resp.Indexes, index)
		}
	}

	// Marshal SHOW GRANTS result.
	{
		const (
//.........这里部分代码省略.........

// TableDetails is an endpoint that returns columns, indices, and other
// relevant details for the specified table.
func (s *adminServer) TableDetails(
	ctx context.Context, req *serverpb.TableDetailsRequest,
) (*serverpb.TableDetailsResponse, error) {
	args := sql.SessionArgs{User: s.getUser(req)}
	session := sql.NewSession(ctx, args, s.server.sqlExecutor, nil)

	// TODO(cdo): Use real placeholders for the table and database names when we've extended our SQL
	// grammar to allow that.
	escDBName := parser.Name(req.Database).String()
	escTableName := parser.Name(req.Table).String()
	escQualTable := fmt.Sprintf("%s.%s", escDBName, escTableName)
	query := fmt.Sprintf("SHOW COLUMNS FROM %s; SHOW INDEX FROM %s; SHOW GRANTS ON TABLE %s; SHOW CREATE TABLE %s;",
		escQualTable, escQualTable, escQualTable, escQualTable)
	r := s.server.sqlExecutor.ExecuteStatements(session, query, nil)
	if err := s.firstNotFoundError(r.ResultList); err != nil {
		return nil, grpc.Errorf(codes.NotFound, "%s", err)
	}
	if err := s.checkQueryResults(r.ResultList, 4); err != nil {
		return nil, err
	}

	var resp serverpb.TableDetailsResponse

	// Marshal SHOW COLUMNS result.
	//
	// TODO(cdo): protobuf v3's default behavior for fields with zero values (e.g. empty strings)
	// is to suppress them. So, if protobuf field "foo" is an empty string, "foo" won't show
	// up in the marshalled JSON. I feel that this is counterintuitive, and this should be fixed
	// for our API.
	{
		const (
			fieldCol   = "Field" // column name
			typeCol    = "Type"
			nullCol    = "Null"
			defaultCol = "Default"
		)
		scanner := makeResultScanner(r.ResultList[0].Columns)
		for _, row := range r.ResultList[0].Rows {
			var col serverpb.TableDetailsResponse_Column
			if err := scanner.Scan(row, fieldCol, &col.Name); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, typeCol, &col.Type); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, nullCol, &col.Nullable); err != nil {
				return nil, err
			}
			isDefaultNull, err := scanner.IsNull(row, defaultCol)
			if err != nil {
				return nil, err
			}
			if !isDefaultNull {
				if err := scanner.Scan(row, defaultCol, &col.DefaultValue); err != nil {
					return nil, err
				}
			}
			resp.Columns = append(resp.Columns, col)
		}
	}

	// Marshal SHOW INDEX result.
	{
		const (
			nameCol      = "Name"
			uniqueCol    = "Unique"
			seqCol       = "Seq"
			columnCol    = "Column"
			directionCol = "Direction"
			storingCol   = "Storing"
		)
		scanner := makeResultScanner(r.ResultList[1].Columns)
		for _, row := range r.ResultList[1].Rows {
			// Marshal grant, splitting comma-separated privileges into a proper slice.
			var index serverpb.TableDetailsResponse_Index
			if err := scanner.Scan(row, nameCol, &index.Name); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, uniqueCol, &index.Unique); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, seqCol, &index.Seq); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, columnCol, &index.Column); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, directionCol, &index.Direction); err != nil {
				return nil, err
			}
			if err := scanner.Scan(row, storingCol, &index.Storing); err != nil {
				return nil, err
			}
			resp.Indexes = append(resp.Indexes, index)
		}
	}

	// Marshal SHOW GRANTS result.
//.........这里部分代码省略.........

func TestAdminAPITableDetails(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s := StartTestServer(t)
	defer s.Stop()

	session := sql.NewSession(sql.SessionArgs{User: security.RootUser}, s.sqlExecutor, nil)
	setupQueries := []string{
		"CREATE DATABASE test",
		`
CREATE TABLE test.tbl (
	nulls_allowed INT,
	nulls_not_allowed INT NOT NULL DEFAULT 1000,
	default2 INT DEFAULT 2,
	string_default STRING DEFAULT 'default_string'
)`,
		"GRANT SELECT ON test.tbl TO readonly",
		"GRANT SELECT,UPDATE,DELETE ON test.tbl TO app",
		"CREATE INDEX descIdx ON test.tbl (default2 DESC)",
	}

	for _, q := range setupQueries {
		res := s.sqlExecutor.ExecuteStatements(session, q, nil)
		if res.ResultList[0].PErr != nil {
			t.Fatalf("error executing '%s': %s", q, res.ResultList[0].PErr)
		}
	}

	// Perform API call.
	var resp TableDetailsResponse
	if err := apiGet(s, "databases/test/tables/tbl", &resp); err != nil {
		t.Fatal(err)
	}

	// Verify columns.
	expColumns := []TableDetailsResponse_Column{
		{Name: "nulls_allowed", Type: "INT", Nullable: true, Default: ""},
		{Name: "nulls_not_allowed", Type: "INT", Nullable: false, Default: "1000"},
		{Name: "default2", Type: "INT", Nullable: true, Default: "2"},
		{Name: "string_default", Type: "STRING", Nullable: true, Default: "'default_string'"},
		{Name: "rowid", Type: "INT", Nullable: false, Default: "unique_rowid()"},
	}
	testutils.SortStructs(expColumns, "Name")
	testutils.SortStructs(resp.Columns, "Name")
	if a, e := len(resp.Columns), len(expColumns); a != e {
		t.Fatalf("# of result columns %d != expected %d (got: %#v)", a, e, resp.Columns)
	}
	for i, a := range resp.Columns {
		e := expColumns[i]
		if a.String() != e.String() {
			t.Fatalf("mismatch at index %d: actual %#v != %#v", i, a, e)
		}
	}

	// Verify grants.
	expGrants := []TableDetailsResponse_Grant{
		{User: security.RootUser, Privileges: []string{"ALL"}},
		{User: "app", Privileges: []string{"DELETE", "SELECT", "UPDATE"}},
		{User: "readonly", Privileges: []string{"SELECT"}},
	}
	testutils.SortStructs(expGrants, "User")
	testutils.SortStructs(resp.Grants, "User")
	if a, e := len(resp.Grants), len(expGrants); a != e {
		t.Fatalf("# of grant columns %d != expected %d (got: %#v)", a, e, resp.Grants)
	}
	for i, a := range resp.Grants {
		e := expGrants[i]
		sort.Strings(a.Privileges)
		sort.Strings(e.Privileges)
		if a.String() != e.String() {
			t.Fatalf("mismatch at index %d: actual %#v != %#v", i, a, e)
		}
	}

	// Verify indexes.
	expIndexes := []TableDetailsResponse_Index{
		{Name: "primary", Column: "rowid", Direction: "ASC", Unique: true, Seq: 1},
		{Name: "descIdx", Column: "default2", Direction: "DESC", Unique: false, Seq: 1},
	}
	testutils.SortStructs(expIndexes, "Column")
	testutils.SortStructs(resp.Indexes, "Column")
	for i, a := range resp.Indexes {
		e := expIndexes[i]
		if a.String() != e.String() {
			t.Fatalf("mismatch at index %d: actual %#v != %#v", i, a, e)
		}
	}

	if a, e := resp.RangeCount, int64(1); a != e {
		t.Fatalf("# of ranges %d != expected %d", a, e)
	}
}