#6 Escaping broken for SQLite3

[John Goerzen]

Hello,

I noticed that HSQL was causing backslashes to be
duplicated on data I'm inserting into a SQLite3 DB.

Say I have a string that contains this literal:

Test\One

This would be represented as a Haskell literal as:

"Test\\One"

And as a SQL92 string as:

'Test\One'

However, HSQL, with toSqlValue, is converting it to:

'Test\\One'

Now, this is correct for PostgreSQL and MySQL, at
least, from my reading of the docs. However, it is
*not* correct for SQLite3, and results in this being
added to the SQLite db:

Test\\One

The correct approach would be to make string escaping
handled on a case-by-case basis. (Note that in this
case, SQLite3 is compliant with SQL92, but PostgreSQL
and MySQL are not.)

Even better would be to call the C API functions for
each individual DB to escape the string. (This could
be especially important for ODBC.) For instance,
PostgreSQL has this:

http://www.postgresql.org/docs/8.0/interactive/libpq-exec.html#LIBPQ-EXEC-ESCAPE-STRING

As it is, I cannot rely on HSQL to reliably handle strings.

I'm not sure what the best fix for this would be -- it
seems that having a generic SqlBind may be an issue here.