Add -p[1] performance statistics flag

Implements the -p[1] flag for printing performance statistics after each result set:
- -p or -p0: Human-readable format with network packet size, transaction count, and timing
- -p1: Colon-separated format for spreadsheet/script processing

Statistics include:
- Network packet size (bytes)
- Transaction count
- Clock time: total, average, and transactions per second

Fixes compatibility with ODBC sqlcmd -p flag.

Author: dlevy-msft-sql

cmd/sqlcmd/sqlcmd.go

@@ -82,6 +82,9 @@ type SQLCmdArguments struct {
 	ChangePassword              string
 	ChangePasswordAndExit       string
 	TraceFile                   string
+	// PrintStatistics prints performance statistics after each batch
+	// nil = disabled, 0 = human-readable, 1 = colon-separated
+	PrintStatistics *int
 	// Keep Help at the end of the list
 	Help bool
 }
@@ -126,6 +129,7 @@ const (
 	disableCmdAndWarn       = "disable-cmd-and-warn"
 	listServers             = "list-servers"
 	removeControlCharacters = "remove-control-characters"
+	printStatistics         = "print-statistics"
 )
 
 func encryptConnectionAllowsTLS(value string) bool {
@@ -330,6 +334,7 @@ func checkDefaultValue(args []string, i int) (val string) {
 		'k': "0",
 		'L': "|", // | is the sentinel for no value since users are unlikely to use it. It's "reserved" in most shells
 		'X': "0",
+		'p': "0",
 	}
 	if isFlag(args[i]) && len(args[i]) == 2 && (len(args) == i+1 || args[i+1][0] == '-') {
 		if v, ok := flags[rune(args[i][1])]; ok {
@@ -393,6 +398,7 @@ func SetScreenWidthFlags(args *SQLCmdArguments, rootCmd *cobra.Command) {
 	args.DisableCmd = getOptionalIntArgument(rootCmd, disableCmdAndWarn)
 	args.ErrorsToStderr = getOptionalIntArgument(rootCmd, errorsToStderr)
 	args.RemoveControlCharacters = getOptionalIntArgument(rootCmd, removeControlCharacters)
+	args.PrintStatistics = getOptionalIntArgument(rootCmd, printStatistics)
 }
 
 func setFlags(rootCmd *cobra.Command, args *SQLCmdArguments) {
@@ -474,6 +480,7 @@ func setFlags(rootCmd *cobra.Command, args *SQLCmdArguments) {
 	_ = rootCmd.Flags().BoolP("enable-quoted-identifiers", "I", true, localizer.Sprintf("Provided for backward compatibility. Quoted identifiers are always enabled"))
 	_ = rootCmd.Flags().BoolP("client-regional-setting", "R", false, localizer.Sprintf("Provided for backward compatibility. Client regional settings are not used"))
 	_ = rootCmd.Flags().IntP(removeControlCharacters, "k", 0, localizer.Sprintf("%s Remove control characters from output. Pass 1 to substitute a space per character, 2 for a space per consecutive characters", "-k [1|2]"))
+	_ = rootCmd.Flags().IntP(printStatistics, "p", -1, localizer.Sprintf("%s Print performance statistics for every result set. Pass 1 to output in colon-separated format", "-p[1]"))
 	rootCmd.Flags().BoolVarP(&args.EchoInput, "echo-input", "e", false, localizer.Sprintf("Echo input"))
 	rootCmd.Flags().IntVarP(&args.QueryTimeout, "query-timeout", "t", 0, "Query timeout")
 	rootCmd.Flags().BoolVarP(&args.EnableColumnEncryption, "enable-column-encryption", "g", false, localizer.Sprintf("Enable column encryption"))
@@ -543,6 +550,14 @@ func normalizeFlags(cmd *cobra.Command) error {
 				err = invalidParameterError("-k", v, "1", "2")
 				return pflag.NormalizedName("")
 			}
+		case printStatistics:
+			switch v {
+			case "0", "1":
+				return pflag.NormalizedName(name)
+			default:
+				err = invalidParameterError("-p", v, "0", "1")
+				return pflag.NormalizedName("")
+			}
 		}
 
 		return pflag.NormalizedName(name)
@@ -829,6 +844,7 @@ func run(vars *sqlcmd.Variables, args *SQLCmdArguments) (int, error) {
 
 	s.Connect = &connectConfig
 	s.Format = sqlcmd.NewSQLCmdDefaultFormatter(args.TrimSpaces, args.getControlCharacterBehavior())
+	s.PrintStatistics = args.PrintStatistics
 	if args.OutputFile != "" {
 		err = s.RunCommand(s.Cmd["OUT"], []string{args.OutputFile})
 		if err != nil {

cmd/sqlcmd/sqlcmd_test.go

@@ -123,6 +123,16 @@ func TestValidCommandLineToArgsConversion(t *testing.T) {
 		{[]string{"-N", "true", "-J", "/path/to/cert2.pem"}, func(args SQLCmdArguments) bool {
 			return args.EncryptConnection == "true" && args.ServerCertificate == "/path/to/cert2.pem"
 		}},
+		// Test -p flag for performance statistics
+		{[]string{"-p"}, func(args SQLCmdArguments) bool {
+			return args.PrintStatistics != nil && *args.PrintStatistics == 0
+		}},
+		{[]string{"-p", "1"}, func(args SQLCmdArguments) bool {
+			return args.PrintStatistics != nil && *args.PrintStatistics == 1
+		}},
+		{[]string{"--print-statistics", "0"}, func(args SQLCmdArguments) bool {
+			return args.PrintStatistics != nil && *args.PrintStatistics == 0
+		}},
 	}
 
 	for _, test := range commands {
@@ -178,6 +188,7 @@ func TestInvalidCommandLine(t *testing.T) {
 		{[]string{"-N", "optional", "-J", "/path/to/cert.pem"}, "The -J parameter requires encryption to be enabled (-N true, -N mandatory, or -N strict)."},
 		{[]string{"-N", "disable", "-J", "/path/to/cert.pem"}, "The -J parameter requires encryption to be enabled (-N true, -N mandatory, or -N strict)."},
 		{[]string{"-N", "strict", "-F", "myserver.domain.com", "-J", "/path/to/cert.pem"}, "The -F and the -J options are mutually exclusive."},
+		{[]string{"-p", "2"}, "'-p 2': Unexpected argument. Argument value has to be one of [0 1]."},
 	}
 
 	for _, test := range commands {

pkg/sqlcmd/sqlcmd.go

@@ -88,6 +88,17 @@ type Sqlcmd struct {
 	EchoInput bool
 	colorizer color.Colorizer
 	termchan  chan os.Signal
+	// PrintStatistics controls whether performance statistics are printed after each batch
+	// nil = disabled, 0 = human-readable format, 1 = colon-separated format
+	PrintStatistics *int
+	// stats tracks cumulative statistics for the session
+	stats *SessionStats
+}
+
+// SessionStats tracks cumulative performance statistics for a sqlcmd session
+type SessionStats struct {
+	TotalTransactions int
+	TotalTimeMs       float64
 }
 
 // New creates a new Sqlcmd instance.
@@ -420,6 +431,9 @@ func (s *Sqlcmd) getRunnableQuery(q string) string {
 // -101: No rows found
 // -102: Conversion error occurred when selecting return value
 func (s *Sqlcmd) runQuery(query string) (int, error) {
+	// Start timing for statistics
+	startTime := time.Now()
+
 	retcode := -101
 	s.Format.BeginBatch(query, s.vars, s.GetOutput(), s.GetError())
 	ctx := context.Background()
@@ -508,6 +522,13 @@ func (s *Sqlcmd) runQuery(query string) (int, error) {
 		}
 	}
 	s.Format.EndBatch()
+
+	// Print statistics if enabled
+	if s.PrintStatistics != nil {
+		elapsed := time.Since(startTime)
+		s.printStatistics(elapsed)
+	}
+
 	return retcode, qe
 }
 
@@ -552,6 +573,48 @@ func (s *Sqlcmd) handleError(retcode *int, err error) error {
 	return nil
 }
 
+// printStatistics prints performance statistics for the query
+func (s *Sqlcmd) printStatistics(elapsed time.Duration) {
+	if s.stats == nil {
+		s.stats = &SessionStats{}
+	}
+
+	// Update cumulative statistics
+	s.stats.TotalTransactions++
+	elapsedMs := float64(elapsed.Milliseconds())
+	s.stats.TotalTimeMs += elapsedMs
+
+	// Calculate statistics
+	avgMs := s.stats.TotalTimeMs / float64(s.stats.TotalTransactions)
+	var xactsPerSec float64
+	if s.stats.TotalTimeMs > 0 {
+		xactsPerSec = float64(s.stats.TotalTransactions) / (s.stats.TotalTimeMs / 1000.0)
+	}
+
+	// Get packet size from connection settings
+	packetSize := s.Connect.PacketSize
+	if packetSize == 0 {
+		packetSize = 4096 // default
+	}
+
+	out := s.GetOutput()
+
+	if *s.PrintStatistics == 1 {
+		// Colon-separated format for spreadsheet/script processing
+		_, _ = out.Write([]byte(localizer.Sprintf("Network packet size (bytes):%d%s", packetSize, SqlcmdEol)))
+		_, _ = out.Write([]byte(localizer.Sprintf("%d xact(s):%s", s.stats.TotalTransactions, SqlcmdEol)))
+		_, _ = out.Write([]byte(localizer.Sprintf("Clock Time (ms.): total:%d:avg:%.2f:(%.4f xacts per sec.)%s",
+			int(s.stats.TotalTimeMs), avgMs, xactsPerSec, SqlcmdEol)))
+	} else {
+		// Human-readable format
+		_, _ = out.Write([]byte(SqlcmdEol))
+		_, _ = out.Write([]byte(localizer.Sprintf("Network packet size (bytes): %d%s", packetSize, SqlcmdEol)))
+		_, _ = out.Write([]byte(localizer.Sprintf("%d xact(s):%s", s.stats.TotalTransactions, SqlcmdEol)))
+		_, _ = out.Write([]byte(localizer.Sprintf("Clock Time (ms.): total       %d  avg       %.2f (%.4f xacts per sec.)%s",
+			int(s.stats.TotalTimeMs), avgMs, xactsPerSec, SqlcmdEol)))
+	}
+}
+
 // Log attempts to write driver traces to the current output. It ignores errors
 func (s Sqlcmd) Log(_ context.Context, _ msdsn.Log, msg string) {
 	_, _ = s.GetOutput().Write([]byte("DRIVER:" + msg))