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Editorial Team
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Asked: 2026-05-15T12:54:19+00:00

I’ve been looking at the OTL (Oracle, Odbc and DB2-CLI Template Library) for C++

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I’ve been looking at the OTL (Oracle, Odbc and DB2-CLI Template Library) for C++ database access. I’m unsure of whether the query I pass in is converted to a parameterized query for the underlying database, or if it’s basically just concatenating all the arguments into one big string and passing the query to the database that way. I see that the query you pass in to it can include type information for the arguments, but what happens between then and the query hitting the database, I can’t tell.

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  1. Editorial Team

    OTL author’s response to my e-mail:

    OTL passes queries with placeholders into the DB API layers. The naming conventions for actual bind variables are different for different DB types. Say, for Oracle,

    SELECT * FROM staff WHERE fname=:f_name<char[20]>

    will be translated into:

    SELECT * FROM staff WHERE fname=:f_name

    plus a bunch of host variable bind calls.

    For MS SQL Server, or DB2, the same SELECT would look like this:

    SELECT * FROM staff WHERE fname=?

    It’s described in the manual that you can’t have a placeholder with the same name more than once for MS SQL, DB2. SQL statements with placeholder / bind variables are relatively expensive to create, so if you instantiate an parameterized SQL via an otl_stream, it makes sense to reuse the stream as much as you can.

    If you have more questions, or suggestions on how I can improve the OTL manual, feel free to email me.

    Cheers,
    Sergei

    pheadbaq wrote:

    Hi, I’ve been evaluating C++ DB libraries recently to use as a base for an ORM library I wish to build, and have been gravitating more and more towards the OTL. It looks very nice by the way, and seems like it would meet most of the needs I have. I just have one lingering question that I can’t seem to clarify by reading the docs. Does OTL pass a parameterized query on to the underlying DBMS, or is it concatenating the arguments and query I pass to the OTL stream into a single string and hand that to the DBMS?

    In other words, if I hand OTL this MSSQL query, along with with the string “Bob” as the bind variable:

    SELECT * FROM staff WHERE fname = :f_name<char[20]>

    Does the OTL parser produce this:

    SELECT * FROM staff WHERE fname = 'Bob'

    Or this:

    SELECT * FROM staff WHERE fname = @f_name

    along with my string as a parameter

    I’ve posted this same question to StackOverflow.com if you care to respond there:
    Is C++ OTL SQL database library using parameterized queries under the hood, or string concat?

    Thank you for your time

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