Fix #146: support client_label connection option (#150)

README.md

@@ -102,6 +102,7 @@ Currently supported query arguments are:
 |                |                                    | 'server-strict' = server must support SSL/TLS |
 |                |                                    | {customName} = use custom registered `tls.Config` (see "Using custom TLS config" section below) |
 | backup_server_node    | a list of backup hosts for the client to try to connect if the primary host is unreachable | a comma-seperated list of backup host-port pairs. E.g.<br> 'host1:port1,host2:port2,host3:port3'  |
+| client_label   | Sets a label for the connection on the server. This value appears in the `client_label` column of the SESSIONS system table. | (default) vertica-sql-go-{version}-{pid}-{timestamp} |
 
 To ping the server and validate a connection (as the connection isn't necessarily created at that moment), simply call the *PingContext()* method.
 

connection.go

@@ -217,7 +217,11 @@ func newConnection(connString string) (*connection, error) {
 	}
 
 	result.clientPID = os.Getpid()
-	result.sessionID = fmt.Sprintf("%s-%s-%d-%d", driverName, driverVersion, result.clientPID, time.Now().Unix())
+	if client_label := result.connURL.Query().Get("client_label"); client_label != "" {
+		result.sessionID = client_label
+	} else {
+		result.sessionID = fmt.Sprintf("%s-%s-%d-%d", driverName, driverVersion, result.clientPID, time.Now().Unix())
+	}
 
 	// Read the interpolate flag.
 	if iFlag := result.connURL.Query().Get("use_prepared_statements"); iFlag != "" {

driver_test.go

@@ -167,7 +167,7 @@ func closeConnection(t *testing.T, connDB *sql.DB, teardownScript ...interface{}
 func TestTLSConfiguration(t *testing.T) {
 	connDB := openConnection(t)
 	defer closeConnection(t, connDB)
-	rows, err := connDB.QueryContext(ctx, "SELECT ssl_state FROM sessions")
+	rows, err := connDB.QueryContext(ctx, "SELECT ssl_state FROM sessions WHERE session_id=(SELECT current_session())")
 	assertNoErr(t, err)
 	defer rows.Close()
 
@@ -187,6 +187,20 @@ func TestTLSConfiguration(t *testing.T) {
 	}
 }
 
+func TestClientLabel(t *testing.T) {
+	connDB := openConnection(t)
+	defer closeConnection(t, connDB)
+	rows, err := connDB.QueryContext(ctx, "SELECT client_label FROM sessions WHERE session_id=(SELECT current_session())")
+	assertNoErr(t, err)
+	defer rows.Close()
+
+	var client_label string
+	for rows.Next() {
+		assertNoErr(t, rows.Scan(&client_label))
+		assertEqual(t, client_label, "tests-for-golang")
+	}
+}
+
 func TestBasicQuery(t *testing.T) {
 	connDB := openConnection(t)
 	defer closeConnection(t, connDB)
@@ -1228,7 +1242,7 @@ func init() {
 			testLogger.Fatal("could not register tls config: %v", err)
 		}
 	}
-	myDBConnectString = "vertica://" + *verticaUserName + ":" + *verticaPassword + "@" + *verticaHostPort + "?" + usePreparedStmtsString + "&tlsmode=" + *tlsMode
+	myDBConnectString = "vertica://" + *verticaUserName + ":" + *verticaPassword + "@" + *verticaHostPort + "?" + usePreparedStmtsString + "&tlsmode=" + *tlsMode + "&client_label=tests-for-golang"
 	otherConnectString = "vertica://TestGuy:TestGuyPass@" + *verticaHostPort + "/?tlsmode=" + *tlsMode
 	badConnectString = "vertica://TestGuy:TestGuyBadPass@" + *verticaHostPort + "/?tlsmode=" + *tlsMode
 	failoverConnectString = "vertica://" + *verticaUserName + ":" + *verticaPassword + "@badHost" + "?backup_server_node=abc.com:100000," + *verticaHostPort + ",localhost:port"