static bool detect_types_from_subquery(std::string const& query,
std::string & geometry_field,
mapnik::layer_descriptor & desc,
boost::shared_ptr<sqlite_connection> ds)
{
bool found = false;
boost::shared_ptr<sqlite_resultset> rs(ds->execute_query(query));
if (rs->is_valid() && rs->step_next())
{
for (int i = 0; i < rs->column_count(); ++i)
{
found = true;
const int type_oid = rs->column_type(i);
const char* fld_name = rs->column_name(i);
switch (type_oid)
{
case SQLITE_INTEGER:
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::Integer));
break;
case SQLITE_FLOAT:
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::Double));
break;
case SQLITE_TEXT:
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::String));
break;
case SQLITE_NULL:
// sqlite reports based on value, not actual column type unless
// PRAGMA table_info is used so here we assume the column is a string
// which is a lesser evil than altogether dropping the column
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::String));
break;
case SQLITE_BLOB:
if (geometry_field.empty()
&& (boost::algorithm::icontains(fld_name, "geom") ||
boost::algorithm::icontains(fld_name, "point") ||
boost::algorithm::icontains(fld_name, "linestring") ||
boost::algorithm::icontains(fld_name, "polygon")))
{
geometry_field = std::string(fld_name);
}
break;
default:
#ifdef MAPNIK_DEBUG
std::clog << "Sqlite Plugin: unknown type_oid=" << type_oid << std::endl;
#endif
break;
}
}
}
return found;
}
static bool table_info(std::string & key_field,
bool detected_types,
std::string & field,
std::string & table,
mapnik::layer_descriptor & desc,
std::shared_ptr<sqlite_connection> ds)
{
// http://www.sqlite.org/pragma.html#pragma_table_info
// use pragma table_info to detect primary key
// and to detect types if no subquery is used or
// if the subquery-based type detection failed
std::ostringstream s;
s << "PRAGMA table_info(" << table << ")";
std::shared_ptr<sqlite_resultset> rs(ds->execute_query(s.str()));
bool found_table = false;
bool found_pk = false;
while (rs->is_valid() && rs->step_next())
{
found_table = true;
const char* fld_name = rs->column_text(1);
std::string fld_type(rs->column_text(2));
sqlite_int64 fld_pk = rs->column_integer64(5);
std::transform(fld_type.begin(), fld_type.end(), fld_type.begin(), ::tolower);
// TODO - how to handle primary keys on multiple columns ?
if (key_field.empty() && ! found_pk && fld_pk != 0)
{
key_field = fld_name;
found_pk = true;
}
if (! detected_types)
{
// see 2.1 "Column Affinity" at http://www.sqlite.org/datatype3.html
// TODO - refactor this somehow ?
if (field.empty()
&& ((boost::algorithm::contains(fld_type, "geom") ||
boost::algorithm::contains(fld_type, "point") ||
boost::algorithm::contains(fld_type, "linestring") ||
boost::algorithm::contains(fld_type, "polygon"))
||
(boost::algorithm::icontains(fld_name, "geom") ||
boost::algorithm::icontains(fld_name, "point") ||
boost::algorithm::icontains(fld_name, "linestring") ||
boost::algorithm::icontains(fld_name, "polygon")))
)
{
field = std::string(fld_name);
}
else if (boost::algorithm::contains(fld_type, "int"))
{
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::Integer));
}
else if (boost::algorithm::contains(fld_type, "text") ||
boost::algorithm::contains(fld_type, "char") ||
boost::algorithm::contains(fld_type, "clob"))
{
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::String));
}
else if (boost::algorithm::contains(fld_type, "real") ||
boost::algorithm::contains(fld_type, "floa") ||
boost::algorithm::contains(fld_type, "doub"))
{
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::Double));
}
else if (boost::algorithm::contains(fld_type, "blob"))
{
if (! field.empty())
{
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::String));
}
}
else
{
// "Column Affinity" says default to "Numeric" but for now we pass..
//desc_.add_descriptor(attribute_descriptor(fld_name,mapnik::Double));
desc.add_descriptor(mapnik::attribute_descriptor(fld_name, mapnik::String));
#ifdef MAPNIK_LOG
// Do not fail when we specify geometry_field in XML file
if (field.empty())
{
MAPNIK_LOG_DEBUG(sqlite) << "Column '"
<< std::string(fld_name)
<< "' unhandled due to unknown type: '"
<< fld_type
<< "', using String";
}
#endif
}
}
}
return found_table;
}