更新语句可在SQL Developer中工作，但不能在C＃中工作

Question

I have a small update query which works in SQL Developer.

UPDATE people
SET months = 8
WHERE number = 599

Fairly straight forward. And it works - this also works in C#. The problem is the moment I want to use Parameters (which works on number but not on months) it will stop working.

I have this code in C#:

 using (OracleConnection con = new OracleConnection(connectionString))
        {
            con.Open();
            OracleCommand command = con.CreateCommand();
            command.CommandType = CommandType.Text;
            command.CommandText = "UPDATE people " +
                              "SET months = :months " +
                              "WHERE number = :number";
            command.Parameters.Add(":number", OracleDbType.Int32).Value = number;
            command.Parameters.Add(":months", OracleDbType.Int32).Value = months;

            command.ExecuteNonQuery();
        }

They are both of type Number in oracle, and I've tried changing the OracleDbType to Decimal, and pretty much everything without success. The odd thing is, that the :number parameters works, but months doesn't get updated (it won't crash, it just doesn't update). However if i change the :months parameter, to a static value like 7 - it will work.

Answer 1

You should add parameters without leading ':' (look here ), try this:

using (OracleConnection con = new OracleConnection(connectionString))
{
    con.Open();
    OracleCommand command = con.CreateCommand();
    command.CommandType = CommandType.Text;
    command.CommandText = "UPDATE people" +
                      "SET months = :months " +
                      "WHERE number = :number";
    command.Parameters.Add("number", OracleDbType.Int32).Value = number;
    command.Parameters.Add("months", OracleDbType.Int32).Value = months;

    command.ExecuteNonQuery();
}

Also you are missing space after :months in query.

Answer 2

Alright, i found out why this wasn't working, it wasn't because of the colons (you can add colons in parameters without it being a problem):

command.Parameters.Add(":months", OracleDbType.Int32).Value = months;

The problem was that i was adding the parameters in a different order than I was using them.

So if in your SQL statement you are adding parameters in a specific order, you should follow that order when you add your OracleCommand.Parameters, like so:

using (OracleConnection con = new OracleConnection(connectionString))
    {
        con.Open();
        OracleCommand command = con.CreateCommand();
        command.CommandType = CommandType.Text;
        command.CommandText = "UPDATE people " +
                          "SET months = :months " +
                          "WHERE number = :number";
        command.Parameters.Add(":months", OracleDbType.Int32).Value = months;
        command.Parameters.Add(":number", OracleDbType.Int32).Value = number;

        command.ExecuteNonQuery();
    }

Answer 3

your command text should be

 command.CommandText = "UPDATE people SET months = :months WHERE number = :number";

Note the spaces i have added