[SQLite]

In something like this:

CREATE TABLE t1(a INT, b TEXT); INSERT INTO t1(a,b) VALUES(1,'2'); SELECT * FROM t1 WHERE a=?;

The type of the ? is ambiguous. You can say that it "prefers" an integer, but most RDBMSes will also accept a string literal in place of the ?:

SELECT * FROM t1 WHERE a='1'; -- works in PG, MySQL, SQLServer, and Oracle

[sradman]

I'm interested in the API interface while the string literal example is more about the SQL language. JDBC has long provided prepared statement metadata that is used extensively by numerous tools.