ORA-01008: not all variables bound. They are bound

You have two references to the :lot_priprc binding variable -- while it should require you to only set the variable's value once and bind it in both places, I've had problems where this didn't work and had to treat each copy as a different variable. A pain, but it worked.

I know this is an old question, but it hasn't been correctly addressed, so I'm answering it for others who may run into this problem.

By default Oracle's ODP.net binds variables by position, and treats each position as a new variable.

Treating each copy as a different variable and setting it's value multiple times is a workaround and a pain, as furman87 mentioned, and could lead to bugs, if you are trying to rewrite the query and move things around.

The correct way is to set the BindByName property of OracleCommand to true as below:

var cmd = new OracleCommand(cmdtxt, conn);
cmd.BindByName = true;

You could also create a new class to encapsulate OracleCommand setting the BindByName to true on instantiation, so you don't have to set the value each time. This is discussed in this post

I found how to run the query without error, but I hesitate to call it a "solution" without really understanding the underlying cause.

This more closely resembles the beginning of my actual query:

-- Comment
-- More comment
SELECT rf.flowrow, rf.stage, rf.process,
rf.instr instnum, rf.procedure_id, rtd_history.runtime, rtd_history.waittime
FROM
(
    -- Comment at beginning of subquery
    -- These two comment lines are the problem
    SELECT sub2.flowrow, sub2.stage, sub2.process, sub2.instr, sub2.pid
    FROM ( ...

The second set of comments above, at the beginning of the subquery, were the problem. When removed, the query executes. Other comments are fine. This is not a matter of some rogue or missing newline causing the following line to be commented, because the following line is a SELECT. A missing select would yield a different error than "not all variables bound."

I asked around and found one co-worker who has run into this -- comments causing query failures -- several times. Does anyone know how this can be the cause? It is my understanding that the very first thing a DBMS would do with comments is see if they contain hints, and if not, remove them during parsing. How can an ordinary comment containing no unusual characters (just letters and a period) cause an error? Bizarre.

On Charles' comment problem: to make things worse, let

:p1 = 'TRIALDEV'

via a Command Parameter, then execute

select T.table_name as NAME, COALESCE(C.comments, '===') as DESCRIPTION
from all_all_tables T
Inner Join all_tab_comments C on T.owner = C.owner and T.table_name = C.table_name
where Upper(T.owner)=:p1
order by T.table_name

558 line(s) affected. Processing time: 00:00:00.6535711

and when changing the literal string from === to ---

select T.table_name as NAME, COALESCE(C.comments, '---') as DESCRIPTION
[...from...same-as-above...]

ORA-01008: not all variables bound

Both statements execute fine in SQL Developer. The shortened code:

            Using con = New OracleConnection(cs)
                con.Open()
                Using cmd = con.CreateCommand()
                    cmd.CommandText = cmdText
                    cmd.Parameters.Add(pn, OracleDbType.NVarchar2, 250).Value = p
                    Dim tbl = New DataTable
                    Dim da = New OracleDataAdapter(cmd)
                    da.Fill(tbl)
                    Return tbl
                End Using
            End Using

using Oracle.ManagedDataAccess.dll Version 4.121.2.0 with the default settings in VS2015 on the .Net 4.61 platform.

So somewhere in the call chain, there might be a parser that is a bit too aggressively looking for one-line-comments started by -- in the commandText. But even if this would be true, the error message "not all variables bound" is at least misleading.