本文整理汇总了C++中query::variables方法的典型用法代码示例。如果您正苦于以下问题：C++ query::variables方法的具体用法？C++ query::variables怎么用？C++ query::variables使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类query的用法示例。
在下文中一共展示了query::variables方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: features_with_context
//.........这里部分代码省略.........
else
{
// Always get a connection in synchronous mode
conn = pool->borrowObject();
if(!conn )
{
throw mapnik::datasource_exception("Postgis Plugin: Null connection");
}
}
if (geometryColumn_.empty())
{
std::ostringstream s_error;
s_error << "PostGIS: geometry name lookup failed for table '";
if (! schema_.empty())
{
s_error << schema_ << ".";
}
s_error << geometry_table_
<< "'. Please manually provide the 'geometry_field' parameter or add an entry "
<< "in the geometry_columns for '";
if (! schema_.empty())
{
s_error << schema_ << ".";
}
s_error << geometry_table_ << "'.";
throw mapnik::datasource_exception(s_error.str());
}
std::ostringstream s;
const double px_gw = 1.0 / std::get<0>(q.resolution());
const double px_gh = 1.0 / std::get<1>(q.resolution());
s << "SELECT ST_AsBinary(";
if (simplify_geometries_) {
s << "ST_Simplify(";
}
s << "\"" << geometryColumn_ << "\"";
if (simplify_geometries_) {
// 1/20 of pixel seems to be a good compromise to avoid
// drop of collapsed polygons.
// See https://github.com/mapnik/mapnik/issues/1639
const double tolerance = std::min(px_gw, px_gh) / 20.0;
s << ", " << tolerance << ")";
}
s << ") AS geom";
mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
std::set<std::string> const& props = q.property_names();
std::set<std::string>::const_iterator pos = props.begin();
std::set<std::string>::const_iterator end = props.end();
if (! key_field_.empty())
{
mapnik::sql_utils::quote_attr(s, key_field_);
ctx->push(key_field_);
for (; pos != end; ++pos)
{
if (*pos != key_field_)
{
mapnik::sql_utils::quote_attr(s, *pos);
ctx->push(*pos);
}
}
}
else
{
for (; pos != end; ++pos)
{
mapnik::sql_utils::quote_attr(s, *pos);
ctx->push(*pos);
}
}
std::string table_with_bbox = populate_tokens(table_, scale_denom, box, px_gw, px_gh, q.variables());
s << " FROM " << table_with_bbox;
if (row_limit_ > 0)
{
s << " LIMIT " << row_limit_;
}
std::shared_ptr<IResultSet> rs = get_resultset(conn, s.str(), pool, proc_ctx);
return std::make_shared<postgis_featureset>(rs, ctx, desc_.get_encoding(), !key_field_.empty());
}
return featureset_ptr();
}示例2: features_with_context
//.........这里部分代码省略.........
s << "," << twkb_tolerance << ",true)";
// ! ST_TWKB()
s << "," << twkb_rounding << ") AS geom";
}
else
{
s << "SELECT ST_AsBinary(";
if (simplify_geometries_)
{
s << "ST_Simplify(";
}
if (simplify_clip_resolution_ > 0.0 && simplify_clip_resolution_ > px_sz)
{
s << "ST_ClipByBox2D(";
}
if (simplify_geometries_ && simplify_snap_ratio_ > 0.0)
{
s<< "ST_SnapToGrid(";
}
// Geometry column!
s << "\"" << geometryColumn_ << "\"";
// ! ST_SnapToGrid()
if (simplify_geometries_ && simplify_snap_ratio_ > 0.0)
{
const double tolerance = px_sz * simplify_snap_ratio_;
s << "," << tolerance << ")";
}
// ! ST_ClipByBox2D()
if (simplify_clip_resolution_ > 0.0 && simplify_clip_resolution_ > px_sz)
{
s << "," << sql_bbox(box) << ")";
}
// ! ST_Simplify()
if (simplify_geometries_)
{
const double tolerance = px_sz * simplify_dp_ratio_;
s << ", " << tolerance;
// Add parameter to ST_Simplify to keep collapsed geometries
if (simplify_dp_preserve_)
{
s << ", true";
}
s << ")";
}
// ! ST_AsBinary()
s << ") AS geom";
}
mapnik::context_ptr ctx = std::make_shared<mapnik::context_type>();
std::set<std::string> const& props = q.property_names();
std::set<std::string>::const_iterator pos = props.begin();
std::set<std::string>::const_iterator end = props.end();
if (! key_field_.empty())
{
mapnik::sql_utils::quote_attr(s, key_field_);
if (key_field_as_attribute_)
{
ctx->push(key_field_);
}
for (; pos != end; ++pos)
{
if (*pos != key_field_)
{
mapnik::sql_utils::quote_attr(s, *pos);
ctx->push(*pos);
}
}
}
else
{
for (; pos != end; ++pos)
{
mapnik::sql_utils::quote_attr(s, *pos);
ctx->push(*pos);
}
}
std::string table_with_bbox = populate_tokens(table_, scale_denom, box, px_gw, px_gh, q.variables());
s << " FROM " << table_with_bbox;
if (row_limit_ > 0)
{
s << " LIMIT " << row_limit_;
}
std::shared_ptr<IResultSet> rs = get_resultset(conn, s.str(), pool, proc_ctx);
return std::make_shared<postgis_featureset>(rs, ctx, desc_.get_encoding(), !key_field_.empty(),
key_field_as_attribute_, twkb_encoding_);
}
return mapnik::make_invalid_featureset();
}