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MySQL Load: Combine sql and exit signal in one port command #724

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Merged
greg-rychlewski merged 4 commits into from
Apr 2, 2026
Merged

MySQL Load: Combine sql and exit signal in one port command #724

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bb837c3
combine sql and exit signal
greg-rychlewski Apr 2, 2026
2bdd35a
change to message passing
greg-rychlewski Apr 2, 2026
7c0ffcf
fixes
greg-rychlewski Apr 2, 2026
4c4012d
fixes
greg-rychlewski Apr 2, 2026
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4 changes: 2 additions & 2 deletions lib/ecto/adapters/myxql.ex
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Original file line number Diff line number Diff line change
Expand Up @@ -591,10 +591,10 @@ defmodule Ecto.Adapters.MyXQL do
# Trap exits in case mysql dies in the middle of execution so that we can surface the error
old_trap_exit = Process.flag(:trap_exit, true)
port = Port.open({:spawn_executable, abs_cmd}, port_opts)
Port.command(port, contents)
# Use this as a signal to close the port since we cannot
# send an exit command to mysql in batch mode
Port.command(port, ";SELECT '__ECTO_EOF__';\n")
exit_signal = ";SELECT '__ECTO_EOF__';\n"
Port.command(port, [contents, exit_signal])
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@josevalim josevalim Apr 2, 2026

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Another option is to use messages to talk to the port, instead of using command. The message is asynchronous and always succeed:

port ! {self(), {:command, contents}}
port ! {self(), {:command, ";SELECT '__ECTO_EOF__';\n"}}

We will know if it fails when we collect the output below. This way there is no chance we fail prematurely on Port.command. WDYT?

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@greg-rychlewski greg-rychlewski Apr 2, 2026

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nice!

btw I'm not sure if this is expected or not, but when I used port ! ... instead of send(port, ...) I got an error complaining port/1 is not a function. just thought I would let you know in case it's an issue you are not expecting

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@josevalim josevalim Apr 2, 2026

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I used the Erlang syntax cause I was writing some Erlang earlier today 😅 It is all good!

result = collect_output(port, "")
Process.flag(:trap_exit, old_trap_exit)
result
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