sqlite prepared statements - how to debug

Question

I'm writing some c++ code that uses the sqlite3 library. I'm using a prepared statement to which I bind a variable at runtime.

How do I examine the SQL query in the statement after the bindings?

For example, the code below doesn't return a row. When using a premade string and sqlite3_exec, I get the results I expect.

sqlite3_stmt *statement;
const char *query = "SELECT * FROM foo WHERE (name='?');";
sqlite3_prepare_v2(db, query, strlen(query), &statemtnt, NULL);
sqlite3_bind_text(statement, 1, "bar", -1, SQLITE3_STATIC);
int result = sqlite3_step(statement);
// expected: result = SQLITE_ROW
// actual: result = SQLITE_DONE

edit: As Ferdinand stated below, the problem in the query above is the quotes around the ?. However, for the future, I'd still like to know how to inspect the sqlite3_stmt for the actual query that will be executed.

Answer 1

The third parameter of sqlite3_bind_text is supposed to be the value you want to bind - in your code you are trying to bind the query to itself!

Also, lose the semicolon at the end of the SELECT.

Answer 2

The SQL query does not change after the bindings -- your variables aren't inserted into the SQL string or anything.

In addition to what Neil said, drop the quotation marks around the ? placeholder:

"SELECT * FROM foo WHERE name = ?"

Otherwise SQLite won't replace the question mark but will treat it as the string "?".

Answer 3

Don't know sqlite all that well, but the actual query might be logged or you might be able to flip a switch to get it to be logged.