mentat/query-translator
Richard Newman 08d2c613a4 Part 2: expand the definition of a table to include computed tables.
This commit:

- Defines a new kind of column, distinct from the eavt columns in
  `DatomsColumn`, to model the rows projected from subqueries. These
  always name one of two things: a variable, or a variable's type tag.
  Naturally the two cases are thus `Variable` and `VariableTypeTag`.
  These are cheap to clone, given that `Variable` is an `Rc<String>`.
- Defines `Column` as a wrapper around `DatomsColumn` and
  `VariableColumn`. Everywhere we used to use `DatomsColumn` we now
  allow `Column`: particularly in constraints and projections.
- Broadens the definition of a table list in the intermediate
  "query-sql" representation to include a SQL UNION. A UNION is
  represented as a list of queries and an alias.
- Implements translation from a `ComputedTable` to the query-sql
  representation. In this commit we only project vars, not type tags.

Review comment: discuss bind_column_to_var for ValueTypeTag.
Review comment: implement From<Vec<T>> for ConsumableVec<T>.
2017-04-12 19:21:33 -07:00
..
src Part 2: expand the definition of a table to include computed tables. 2017-04-12 19:21:33 -07:00
tests Part 2: implement simple or. 2017-04-07 12:46:25 -07:00
Cargo.toml Implement projection and querying. (#353) r=nalexander 2017-03-06 14:40:10 -08:00
README.md Begin serializing queries to SQL. r=nalexander 2017-02-17 17:54:07 -08:00

This crate turns an algebrized Datalog query into a domain-specific representation of a SQL query, and then uses mentat_sql to turn that into a SQL string to be executed.

This subsumes both planning and query construction, because in Mentat the SQL query is effectively a query plan.