CODEWITHSUNDEEP
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Dr. Whom
Dr. Whom

Reputation: 3

Npgsql F# Parameterized Queries

I'm attempting to use Npgsql parametrized queries in FSharp but I am unable to properly get Npgsql to update the parameter value. Sample code looks as follows:

let ins_command = new NpgsqlCommand("SELECT * FROM test_table WHERE keyid = :keyid")
ins_command.Parameters.Add(new NpgsqlParameter("keyid", NpgsqlTypes.NpgsqlDbType.Integer)) |> ignore
for key in keys do
    ins_command.Parameters.["keyid"].Value = (box key)
    ins_command.ExecuteScalar())

The "keyid" parameter is always set to null and when viewed as a watch variable it's never set. Without using AddWithValue how can I set these parameters properly in FSharp?

Upvotes: 0

Views: 537

Answers (1)

Vandroiy
Vandroiy

Reputation: 6223

I don't know the library, but the line

ins_command.Parameters.["keyid"].Value = (box key)

looks like it is doing nothing. Unless the = operator has been changed, this is only a test for equality. It should give a compiler warning, as a check for equality is of type bool and this line doesn't do anything with the result.

If you want to use a property setter (or assign to a mutable value), use the operator <-

Upvotes: 2

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