Помогите в чём может быть ошибка

Спойлер: error

No results were returned by the query.
org.postgresql.util.PSQLException: No results were returned by the query.
at org.postgresql.jdbc.PgStatement.executeQuery(PgStatement.java:240) ~[?:?]
at com.nightday.dbconn.Main.onCommand(Main.java:81) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at org.bukkit.craftbukkit.v1_16_R3.CraftServer.dispatchCommand(CraftServer.java:763) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at org.bukkit.craftbukkit.v1_16_R3.CraftServer.dispatchServerCommand(CraftServer.java:748) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at net.minecraft.server.v1_16_R3.DedicatedServer.handleCommandQueue(DedicatedServer.java:387) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at net.minecraft.server.v1_16_R3.DedicatedServer.b(DedicatedServer.java:356) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at net.minecraft.server.v1_16_R3.MinecraftServer.a(MinecraftServer.java:1008) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:847) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$0(MinecraftServer.java:164) ~[spigot.jar:2991-Spigot-018b9a0-f3f3094]
at java.lang.Thread.run(Thread.java:829) [?:?]

Код:

ResultSet rs1 = st1.executeQuery("update ndplug set username = '" + sender.getName()  + "' where email = '" + args[0].toString() + "';")) {