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Part 4: correct projection of type tags in the outermost projector.

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Richard Newman 2017-04-11 10:14:33 -07:00
parent d8075aa07d
commit bca8b7e322
1 changed files with 9 additions and 30 deletions
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39
query-projector/src/lib.rs
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@ -37,33 +37,18 @@ use mentat_db::{
use mentat_query::{ use mentat_query::{
Element, Element,
FindSpec, FindSpec,
Variable,
}; };
use mentat_query_algebrizer::{ use mentat_query_algebrizer::{
AlgebraicQuery, AlgebraicQuery,
DatomsColumn, ColumnName,
QualifiedAlias, VariableColumn,
/*
ConjoiningClauses,
DatomsTable,
SourceAlias,
*/
}; };
use mentat_query_sql::{ use mentat_query_sql::{
ColumnOrExpression, ColumnOrExpression,
/*
Constraint,
FromClause,
*/
Name,
Projection, Projection,
ProjectedColumn, ProjectedColumn,
/*
SelectQuery,
TableList,
*/
}; };
error_chain! { error_chain! {
@ -169,14 +154,6 @@ impl TypedIndex {
} }
} }
fn column_name(var: &Variable) -> Name {
var.to_string()
}
fn value_type_tag_name(var: &Variable) -> Name {
format!("{}_value_type_tag", var.as_str())
}
/// Walk an iterator of `Element`s, collecting projector templates and columns. /// Walk an iterator of `Element`s, collecting projector templates and columns.
/// ///
/// Returns a pair: the SQL projection (which should always be a `Projection::Columns`) /// Returns a pair: the SQL projection (which should always be a `Projection::Columns`)
@ -213,7 +190,7 @@ fn project_elements<'a, I: IntoIterator<Item = &'a Element>>(
.expect("Every variable has a binding"); .expect("Every variable has a binding");
let qa = columns[0].clone(); let qa = columns[0].clone();
let name = column_name(var); let name = VariableColumn::Variable(var.clone()).column_name();
if let Some(t) = query.cc.known_type(var) { if let Some(t) = query.cc.known_type(var) {
cols.push(ProjectedColumn(ColumnOrExpression::Column(qa), name)); cols.push(ProjectedColumn(ColumnOrExpression::Column(qa), name));
@ -221,15 +198,17 @@ fn project_elements<'a, I: IntoIterator<Item = &'a Element>>(
templates.push(TypedIndex::Known(i, tag)); templates.push(TypedIndex::Known(i, tag));
i += 1; // We used one SQL column. i += 1; // We used one SQL column.
} else { } else {
let table = qa.0.clone();
cols.push(ProjectedColumn(ColumnOrExpression::Column(qa), name)); cols.push(ProjectedColumn(ColumnOrExpression::Column(qa), name));
templates.push(TypedIndex::Unknown(i, i + 1)); templates.push(TypedIndex::Unknown(i, i + 1));
i += 2; // We used two SQL columns. i += 2; // We used two SQL columns.
// Also project the type from the SQL query. // Also project the type from the SQL query.
let type_name = value_type_tag_name(var); let extracted_alias = query.cc
let type_qa = QualifiedAlias::new(table, DatomsColumn::ValueTypeTag); .extracted_types
cols.push(ProjectedColumn(ColumnOrExpression::Column(type_qa), type_name)); .get(var)
.expect("Every variable has a known type or an extracted type");
let type_name = VariableColumn::VariableTypeTag(var.clone()).column_name();
cols.push(ProjectedColumn(ColumnOrExpression::Column(extracted_alias.clone()), type_name));
} }
} }
} }