icydb_core/db/sql/lowering/
mod.rs

1//! Module: db::sql::lowering
2//! Responsibility: reduced SQL statement lowering into canonical query intent.
3//! Does not own: SQL tokenization/parsing, planner validation policy, or executor semantics.
4//! Boundary: frontend-only translation from parsed SQL statement contracts to `Query<E>`.
5
6mod aggregate;
7mod normalize;
8mod prepare;
9mod select;
10
11///
12/// TESTS
13///
14
15#[cfg(test)]
16mod tests;
17
18use crate::db::{
19    query::intent::QueryError,
20    sql::parser::{SqlExplainMode, SqlStatement},
21};
22#[cfg(test)]
23use crate::{
24    db::{predicate::MissingRowPolicy, query::intent::Query},
25    traits::EntityKind,
26};
27use thiserror::Error as ThisError;
28
29pub(in crate::db::sql::lowering) use aggregate::LoweredSqlGlobalAggregateCommand;
30pub(in crate::db) use aggregate::compile_sql_global_aggregate_command_core_from_prepared;
31pub(crate) use aggregate::compile_sql_global_aggregate_command_from_prepared;
32pub(in crate::db) use aggregate::is_sql_global_aggregate_statement;
33#[cfg(test)]
34pub(crate) use aggregate::{
35    PreparedSqlScalarAggregateDescriptorShape, PreparedSqlScalarAggregateDomain,
36    PreparedSqlScalarAggregateEmptySetBehavior, PreparedSqlScalarAggregateOrderingRequirement,
37    PreparedSqlScalarAggregateRowSource, TypedSqlGlobalAggregateTerminal,
38    compile_sql_global_aggregate_command,
39};
40pub(crate) use aggregate::{
41    PreparedSqlScalarAggregateRuntimeDescriptor, PreparedSqlScalarAggregateStrategy,
42    SqlGlobalAggregateCommand, SqlGlobalAggregateCommandCore,
43    bind_lowered_sql_explain_global_aggregate_structural,
44};
45pub(crate) use prepare::{lower_sql_command_from_prepared_statement, prepare_sql_statement};
46pub(in crate::db::sql::lowering) use select::apply_lowered_base_query_shape;
47#[cfg(test)]
48pub(in crate::db) use select::apply_lowered_select_shape;
49pub(crate) use select::{LoweredBaseQueryShape, LoweredSelectShape};
50pub(in crate::db) use select::{
51    bind_lowered_sql_delete_query_structural, bind_lowered_sql_query,
52    bind_lowered_sql_query_structural, bind_lowered_sql_select_query_structural,
53};
54
55///
56/// LoweredSqlCommand
57///
58/// Generic-free SQL command shape after reduced SQL parsing and entity-route
59/// normalization.
60/// This keeps statement-shape lowering shared across entities before typed
61/// `Query<E>` binding happens at the execution boundary.
62///
63#[derive(Clone, Debug)]
64pub struct LoweredSqlCommand(pub(in crate::db::sql::lowering) LoweredSqlCommandInner);
65
66#[derive(Clone, Debug)]
67pub(in crate::db::sql::lowering) enum LoweredSqlCommandInner {
68    Query(LoweredSqlQuery),
69    Explain {
70        mode: SqlExplainMode,
71        query: LoweredSqlQuery,
72    },
73    ExplainGlobalAggregate {
74        mode: SqlExplainMode,
75        command: LoweredSqlGlobalAggregateCommand,
76    },
77    DescribeEntity,
78    ShowIndexesEntity,
79    ShowColumnsEntity,
80    ShowEntities,
81}
82
83///
84/// SqlCommand
85///
86/// Test-only typed SQL command shell over the shared lowered SQL surface.
87/// Runtime dispatch now consumes `LoweredSqlCommand` directly, but lowering
88/// tests still validate typed binding behavior on this local envelope.
89///
90#[cfg(test)]
91#[derive(Debug)]
92pub(crate) enum SqlCommand<E: EntityKind> {
93    Query(Query<E>),
94    Explain {
95        mode: SqlExplainMode,
96        query: Query<E>,
97    },
98    ExplainGlobalAggregate {
99        mode: SqlExplainMode,
100        command: SqlGlobalAggregateCommand<E>,
101    },
102    DescribeEntity,
103    ShowIndexesEntity,
104    ShowColumnsEntity,
105    ShowEntities,
106}
107
108impl LoweredSqlCommand {
109    #[must_use]
110    pub(in crate::db) const fn query(&self) -> Option<&LoweredSqlQuery> {
111        match &self.0 {
112            LoweredSqlCommandInner::Query(query) => Some(query),
113            LoweredSqlCommandInner::Explain { .. }
114            | LoweredSqlCommandInner::ExplainGlobalAggregate { .. }
115            | LoweredSqlCommandInner::DescribeEntity
116            | LoweredSqlCommandInner::ShowIndexesEntity
117            | LoweredSqlCommandInner::ShowColumnsEntity
118            | LoweredSqlCommandInner::ShowEntities => None,
119        }
120    }
121
122    #[must_use]
123    pub(in crate::db) fn into_query(self) -> Option<LoweredSqlQuery> {
124        match self.0 {
125            LoweredSqlCommandInner::Query(query) => Some(query),
126            LoweredSqlCommandInner::Explain { .. }
127            | LoweredSqlCommandInner::ExplainGlobalAggregate { .. }
128            | LoweredSqlCommandInner::DescribeEntity
129            | LoweredSqlCommandInner::ShowIndexesEntity
130            | LoweredSqlCommandInner::ShowColumnsEntity
131            | LoweredSqlCommandInner::ShowEntities => None,
132        }
133    }
134
135    #[must_use]
136    pub(in crate::db) const fn explain_query(&self) -> Option<(SqlExplainMode, &LoweredSqlQuery)> {
137        match &self.0 {
138            LoweredSqlCommandInner::Explain { mode, query } => Some((*mode, query)),
139            LoweredSqlCommandInner::Query(_)
140            | LoweredSqlCommandInner::ExplainGlobalAggregate { .. }
141            | LoweredSqlCommandInner::DescribeEntity
142            | LoweredSqlCommandInner::ShowIndexesEntity
143            | LoweredSqlCommandInner::ShowColumnsEntity
144            | LoweredSqlCommandInner::ShowEntities => None,
145        }
146    }
147}
148
149///
150/// LoweredSqlQuery
151///
152/// Generic-free executable SQL query shape prepared before typed query binding.
153/// Select and delete lowering stay shared until the final `Query<E>` build.
154///
155#[derive(Clone, Debug)]
156pub(crate) enum LoweredSqlQuery {
157    Select(LoweredSelectShape),
158    Delete(LoweredBaseQueryShape),
159}
160
161impl LoweredSqlQuery {
162    // Report whether this lowered query carries grouped execution semantics.
163    pub(crate) const fn has_grouping(&self) -> bool {
164        match self {
165            Self::Select(select) => select.has_grouping(),
166            Self::Delete(_) => false,
167        }
168    }
169}
170
171///
172/// SqlLoweringError
173///
174/// SQL frontend lowering failures before planner validation/execution.
175///
176#[derive(Debug, ThisError)]
177pub(crate) enum SqlLoweringError {
178    #[error("{0}")]
179    Parse(#[from] crate::db::sql::parser::SqlParseError),
180
181    #[error("{0}")]
182    Query(Box<QueryError>),
183
184    #[error("SQL entity '{sql_entity}' does not match requested entity type '{expected_entity}'")]
185    EntityMismatch {
186        sql_entity: String,
187        expected_entity: &'static str,
188    },
189
190    #[error(
191        "unsupported SQL SELECT projection; supported forms are SELECT *, field lists, or grouped aggregate shapes"
192    )]
193    UnsupportedSelectProjection,
194
195    #[error("unsupported SQL SELECT DISTINCT")]
196    UnsupportedSelectDistinct,
197
198    #[error("unsupported SQL GROUP BY projection shape")]
199    UnsupportedSelectGroupBy,
200
201    #[error("unsupported SQL HAVING shape")]
202    UnsupportedSelectHaving,
203}
204
205impl SqlLoweringError {
206    /// Construct one entity-mismatch SQL lowering error.
207    fn entity_mismatch(sql_entity: impl Into<String>, expected_entity: &'static str) -> Self {
208        Self::EntityMismatch {
209            sql_entity: sql_entity.into(),
210            expected_entity,
211        }
212    }
213
214    /// Construct one unsupported SELECT projection SQL lowering error.
215    const fn unsupported_select_projection() -> Self {
216        Self::UnsupportedSelectProjection
217    }
218
219    /// Construct one unsupported SELECT DISTINCT SQL lowering error.
220    const fn unsupported_select_distinct() -> Self {
221        Self::UnsupportedSelectDistinct
222    }
223
224    /// Construct one unsupported SELECT GROUP BY shape SQL lowering error.
225    const fn unsupported_select_group_by() -> Self {
226        Self::UnsupportedSelectGroupBy
227    }
228
229    /// Construct one unsupported SELECT HAVING shape SQL lowering error.
230    const fn unsupported_select_having() -> Self {
231        Self::UnsupportedSelectHaving
232    }
233}
234
235impl From<QueryError> for SqlLoweringError {
236    fn from(value: QueryError) -> Self {
237        Self::Query(Box::new(value))
238    }
239}
240
241///
242/// PreparedSqlStatement
243///
244/// SQL statement envelope after entity-scope normalization and
245/// entity-match validation for one target entity descriptor.
246///
247/// This pre-lowering contract is entity-agnostic and reusable across
248/// dynamic SQL route branches before typed `Query<E>` binding.
249///
250#[derive(Clone, Debug)]
251pub(crate) struct PreparedSqlStatement {
252    pub(in crate::db::sql::lowering) statement: SqlStatement,
253}
254
255#[derive(Clone, Copy, Debug, Eq, PartialEq)]
256pub(crate) enum LoweredSqlLaneKind {
257    Query,
258    Explain,
259    Describe,
260    ShowIndexes,
261    ShowColumns,
262    ShowEntities,
263}
264
265/// Parse and lower one SQL statement into canonical query intent for `E`.
266#[cfg(test)]
267pub(crate) fn compile_sql_command<E: EntityKind>(
268    sql: &str,
269    consistency: MissingRowPolicy,
270) -> Result<SqlCommand<E>, SqlLoweringError> {
271    let statement = crate::db::sql::parser::parse_sql(sql)?;
272
273    compile_sql_command_from_statement::<E>(statement, consistency)
274}
275
276/// Lower one parsed SQL statement into canonical query intent for `E`.
277#[cfg(test)]
278pub(crate) fn compile_sql_command_from_statement<E: EntityKind>(
279    statement: SqlStatement,
280    consistency: MissingRowPolicy,
281) -> Result<SqlCommand<E>, SqlLoweringError> {
282    let prepared = prepare_sql_statement(statement, E::MODEL.name())?;
283
284    compile_sql_command_from_prepared_statement::<E>(prepared, consistency)
285}
286
287/// Lower one prepared SQL statement into canonical query intent for `E`.
288#[cfg(test)]
289pub(crate) fn compile_sql_command_from_prepared_statement<E: EntityKind>(
290    prepared: PreparedSqlStatement,
291    consistency: MissingRowPolicy,
292) -> Result<SqlCommand<E>, SqlLoweringError> {
293    let lowered = lower_sql_command_from_prepared_statement(prepared, E::MODEL.primary_key.name)?;
294
295    bind_lowered_sql_command::<E>(lowered, consistency)
296}
297
298pub(crate) const fn lowered_sql_command_lane(command: &LoweredSqlCommand) -> LoweredSqlLaneKind {
299    match command.0 {
300        LoweredSqlCommandInner::Query(_) => LoweredSqlLaneKind::Query,
301        LoweredSqlCommandInner::Explain { .. }
302        | LoweredSqlCommandInner::ExplainGlobalAggregate { .. } => LoweredSqlLaneKind::Explain,
303        LoweredSqlCommandInner::DescribeEntity => LoweredSqlLaneKind::Describe,
304        LoweredSqlCommandInner::ShowIndexesEntity => LoweredSqlLaneKind::ShowIndexes,
305        LoweredSqlCommandInner::ShowColumnsEntity => LoweredSqlLaneKind::ShowColumns,
306        LoweredSqlCommandInner::ShowEntities => LoweredSqlLaneKind::ShowEntities,
307    }
308}
309
310/// Bind one shared generic-free SQL command shape to the typed query surface.
311#[cfg(test)]
312pub(crate) fn bind_lowered_sql_command<E: EntityKind>(
313    lowered: LoweredSqlCommand,
314    consistency: MissingRowPolicy,
315) -> Result<SqlCommand<E>, SqlLoweringError> {
316    match lowered.0 {
317        LoweredSqlCommandInner::Query(query) => Ok(SqlCommand::Query(bind_lowered_sql_query::<E>(
318            query,
319            consistency,
320        )?)),
321        LoweredSqlCommandInner::Explain { mode, query } => Ok(SqlCommand::Explain {
322            mode,
323            query: bind_lowered_sql_query::<E>(query, consistency)?,
324        }),
325        LoweredSqlCommandInner::ExplainGlobalAggregate { mode, command } => {
326            Ok(SqlCommand::ExplainGlobalAggregate {
327                mode,
328                command: aggregate::bind_lowered_sql_global_aggregate_command::<E>(
329                    command,
330                    consistency,
331                )?,
332            })
333        }
334        LoweredSqlCommandInner::DescribeEntity => Ok(SqlCommand::DescribeEntity),
335        LoweredSqlCommandInner::ShowIndexesEntity => Ok(SqlCommand::ShowIndexesEntity),
336        LoweredSqlCommandInner::ShowColumnsEntity => Ok(SqlCommand::ShowColumnsEntity),
337        LoweredSqlCommandInner::ShowEntities => Ok(SqlCommand::ShowEntities),
338    }
339}
icydb_core/db/sql/lowering/mod.rs

icydb_core/db/sql/lowering/
mod.rs
