Building static strings with C++ Metaprogramming

I'm writing an open source sqlite interface library (mSqliteCpp for instance) that uses c++ classes and types to correctly manage sqlite databases.

So far the library is heavily using TMP to build SQL strings, but I found a possible issue that may somehow affect the efficiency of the library.

I'm using classes to manage Fields definitions, classes definitions, queries and statements. Basically to define a table or a SELECT statement, one defines the fields using proper FieldDef<T> objects, then pass them to a statement builder that returns the correctly formatted SQL statement.

For example:

auto fldId = sqlite::makeFieldDef("id", sqlite::FieldType::Integer());
auto fldName = sqlite::makeFieldDef("name", sqlite::FieldType::Text());
auto fldValue = sqlite::makeFieldDef("value", sqlite::FieldType::Real());

sqlite::statements::Select select("Table", fldId, fldName, fldValue);

ASSERT_EQ(select.string(), "SELECT id,name,value FROM Table;");

Note that each field is strongly typed by the FieldType type passed to the makeFieldDef function, but different fields with similar type can be exchanged. For this reason the SQL statement in the ASSERT call is built at runtime.

I would like to have them built at compile time, at least under certain conditions. For example, developer could use a different class or maybe the constexpr keyword. But at this time I've no idea if this could be achieved.

What are the possible patterns? Can strings be statically built through TMP? I'm using C++11/14.

Thank you.