gluesql_core/query_builder/select/
offset.rs

1use {
2    super::{BuildProjectPlan, BuildQuery, BuildQueryPlan, DistinctNode, ValuesNode},
3    crate::{
4        ast::Query,
5        plan::{OffsetInputPlan, OffsetPlan, QueryPlan},
6        query_builder::{
7            ExprNode, FilterNode, GroupByNode, HavingNode, InnerHashJoinNode,
8            InnerJoinConditionNode, InnerNestedLoopJoinNode, LeftOuterHashJoinNode,
9            LeftOuterJoinConditionNode, LeftOuterNestedLoopJoinNode, OffsetLimitNode, ProjectNode,
10            QueryNode, SelectNode, SelectOrderByNode, SourceNode, ValuesOrderByNode,
11        },
12        result::Result,
13    },
14};
15
16#[derive(Clone, Debug)]
17pub(super) enum PrevNode<'a> {
18    Select(SelectNode<'a>),
19    Values(ValuesNode<'a>),
20    GroupBy(GroupByNode<'a>),
21    Having(HavingNode<'a>),
22    InnerNestedLoop(Box<InnerNestedLoopJoinNode<'a>>),
23    LeftOuterNestedLoop(Box<LeftOuterNestedLoopJoinNode<'a>>),
24    InnerHash(Box<InnerHashJoinNode<'a>>),
25    LeftOuterHash(Box<LeftOuterHashJoinNode<'a>>),
26    InnerCondition(Box<InnerJoinConditionNode<'a>>),
27    LeftOuterCondition(Box<LeftOuterJoinConditionNode<'a>>),
28    Filter(FilterNode<'a>),
29    SelectOrderBy(SelectOrderByNode<'a>),
30    ValuesOrderBy(ValuesOrderByNode<'a>),
31    Distinct(DistinctNode<'a>),
32    ProjectNode(Box<ProjectNode<'a>>),
33}
34
35impl PrevNode<'_> {
36    fn build_offset_input_plan(self) -> Result<OffsetInputPlan> {
37        match self {
38            Self::Select(node) => node.build_project_plan().map(OffsetInputPlan::Project),
39            Self::Values(node) => node.build_values_plan().map(OffsetInputPlan::Values),
40            Self::GroupBy(node) => node.build_project_plan().map(OffsetInputPlan::Project),
41            Self::Having(node) => node.build_project_plan().map(OffsetInputPlan::Project),
42            Self::InnerNestedLoop(node) => node.build_project_plan().map(OffsetInputPlan::Project),
43            Self::LeftOuterNestedLoop(node) => {
44                node.build_project_plan().map(OffsetInputPlan::Project)
45            }
46            Self::InnerHash(node) => node.build_project_plan().map(OffsetInputPlan::Project),
47            Self::LeftOuterHash(node) => node.build_project_plan().map(OffsetInputPlan::Project),
48            Self::InnerCondition(node) => node.build_project_plan().map(OffsetInputPlan::Project),
49            Self::LeftOuterCondition(node) => {
50                node.build_project_plan().map(OffsetInputPlan::Project)
51            }
52            Self::Filter(node) => node.build_project_plan().map(OffsetInputPlan::Project),
53            Self::SelectOrderBy(node) => node
54                .build_select_order_by_plan()
55                .map(OffsetInputPlan::SelectOrderBy),
56            Self::ValuesOrderBy(node) => node
57                .build_values_order_by_plan()
58                .map(OffsetInputPlan::ValuesOrderBy),
59            Self::Distinct(node) => node.build_distinct_plan().map(OffsetInputPlan::Distinct),
60            Self::ProjectNode(node) => node.build_project_plan().map(OffsetInputPlan::Project),
61        }
62    }
63}
64
65impl BuildQuery for PrevNode<'_> {
66    fn build_query(self) -> Result<Query> {
67        match self {
68            Self::Select(node) => node.build_query(),
69            Self::Values(node) => node.build_query(),
70            Self::GroupBy(node) => node.build_query(),
71            Self::Having(node) => node.build_query(),
72            Self::InnerNestedLoop(node) => node.build_query(),
73            Self::LeftOuterNestedLoop(node) => node.build_query(),
74            Self::InnerHash(node) => node.build_query(),
75            Self::LeftOuterHash(node) => node.build_query(),
76            Self::InnerCondition(node) => node.build_query(),
77            Self::LeftOuterCondition(node) => node.build_query(),
78            Self::Filter(node) => node.build_query(),
79            Self::SelectOrderBy(node) => node.build_query(),
80            Self::ValuesOrderBy(node) => node.build_query(),
81            Self::Distinct(node) => node.build_query(),
82            Self::ProjectNode(node) => node.build_query(),
83        }
84    }
85}
86
87impl<'a> From<SelectNode<'a>> for PrevNode<'a> {
88    fn from(node: SelectNode<'a>) -> Self {
89        PrevNode::Select(node)
90    }
91}
92
93impl<'a> From<ValuesNode<'a>> for PrevNode<'a> {
94    fn from(node: ValuesNode<'a>) -> Self {
95        PrevNode::Values(node)
96    }
97}
98
99impl<'a> From<GroupByNode<'a>> for PrevNode<'a> {
100    fn from(node: GroupByNode<'a>) -> Self {
101        PrevNode::GroupBy(node)
102    }
103}
104
105impl<'a> From<HavingNode<'a>> for PrevNode<'a> {
106    fn from(node: HavingNode<'a>) -> Self {
107        PrevNode::Having(node)
108    }
109}
110
111impl<'a> From<InnerNestedLoopJoinNode<'a>> for PrevNode<'a> {
112    fn from(node: InnerNestedLoopJoinNode<'a>) -> Self {
113        Self::InnerNestedLoop(Box::new(node))
114    }
115}
116
117impl<'a> From<LeftOuterNestedLoopJoinNode<'a>> for PrevNode<'a> {
118    fn from(node: LeftOuterNestedLoopJoinNode<'a>) -> Self {
119        Self::LeftOuterNestedLoop(Box::new(node))
120    }
121}
122
123impl<'a> From<InnerHashJoinNode<'a>> for PrevNode<'a> {
124    fn from(node: InnerHashJoinNode<'a>) -> Self {
125        Self::InnerHash(Box::new(node))
126    }
127}
128
129impl<'a> From<LeftOuterHashJoinNode<'a>> for PrevNode<'a> {
130    fn from(node: LeftOuterHashJoinNode<'a>) -> Self {
131        Self::LeftOuterHash(Box::new(node))
132    }
133}
134
135impl<'a> From<InnerJoinConditionNode<'a>> for PrevNode<'a> {
136    fn from(node: InnerJoinConditionNode<'a>) -> Self {
137        Self::InnerCondition(Box::new(node))
138    }
139}
140
141impl<'a> From<LeftOuterJoinConditionNode<'a>> for PrevNode<'a> {
142    fn from(node: LeftOuterJoinConditionNode<'a>) -> Self {
143        Self::LeftOuterCondition(Box::new(node))
144    }
145}
146
147impl<'a> From<FilterNode<'a>> for PrevNode<'a> {
148    fn from(node: FilterNode<'a>) -> Self {
149        PrevNode::Filter(node)
150    }
151}
152
153impl<'a> From<SelectOrderByNode<'a>> for PrevNode<'a> {
154    fn from(node: SelectOrderByNode<'a>) -> Self {
155        Self::SelectOrderBy(node)
156    }
157}
158
159impl<'a> From<ValuesOrderByNode<'a>> for PrevNode<'a> {
160    fn from(node: ValuesOrderByNode<'a>) -> Self {
161        Self::ValuesOrderBy(node)
162    }
163}
164
165impl<'a> From<DistinctNode<'a>> for PrevNode<'a> {
166    fn from(node: DistinctNode<'a>) -> Self {
167        Self::Distinct(node)
168    }
169}
170
171impl<'a> From<ProjectNode<'a>> for PrevNode<'a> {
172    fn from(node: ProjectNode<'a>) -> Self {
173        PrevNode::ProjectNode(Box::new(node))
174    }
175}
176
177#[derive(Clone, Debug)]
178pub struct OffsetNode<'a> {
179    prev_node: PrevNode<'a>,
180    expr: ExprNode<'a>,
181}
182
183impl<'a> OffsetNode<'a> {
184    pub(super) fn new<N: Into<PrevNode<'a>>, T: Into<ExprNode<'a>>>(prev_node: N, expr: T) -> Self {
185        Self {
186            prev_node: prev_node.into(),
187            expr: expr.into(),
188        }
189    }
190
191    pub fn limit<T: Into<ExprNode<'a>>>(self, expr: T) -> OffsetLimitNode<'a> {
192        OffsetLimitNode::new(self, expr)
193    }
194
195    pub fn alias_as(self, table_alias: &'a str) -> SourceNode<'a> {
196        QueryNode::OffsetNode(self).alias_as(table_alias)
197    }
198
199    pub(super) fn build_offset_plan(self) -> Result<OffsetPlan> {
200        let count = self.expr.build_expr_plan()?;
201        let input = self.prev_node.build_offset_input_plan()?;
202
203        Ok(OffsetPlan { input, count })
204    }
205}
206
207impl BuildQueryPlan for OffsetNode<'_> {
208    fn build_query_plan(self) -> Result<QueryPlan> {
209        self.build_offset_plan().map(QueryPlan::Offset)
210    }
211}
212
213impl BuildQuery for OffsetNode<'_> {
214    fn build_query(self) -> Result<Query> {
215        let mut node_data = self.prev_node.build_query()?;
216        node_data.offset = Some(self.expr.build_expr()?);
217
218        Ok(node_data)
219    }
220}
221
222#[cfg(test)]
223mod tests {
224    use {
225        crate::{
226            plan::{
227                HashJoinInputPlan, HashJoinPlan, InnerJoinInputPlan, InnerJoinPlan,
228                OffsetInputPlan, OffsetPlan, ProjectInputPlan, ProjectPlan, ProjectionPlan,
229                QueryPlan, SourcePlan, StatementPlan, TableAccessPlan, TableSourcePlan,
230            },
231            query_builder::{Build, SelectItemList, col, num, table, test_query_builder},
232        },
233        pretty_assertions::assert_eq,
234    };
235
236    #[test]
237    fn offset() {
238        // select node -> offset node -> build
239        let actual = table("Foo").select().offset(10);
240        let expected = "SELECT * FROM Foo OFFSET 10";
241        test_query_builder(actual, expected);
242
243        // group by node -> offset node -> build
244        let actual = table("Foo").select().group_by("id").offset(10);
245        let expected = "SELECT * FROM Foo GROUP BY id OFFSET 10";
246        test_query_builder(actual, expected);
247
248        // having node -> offset node -> build
249        let actual = table("Foo")
250            .select()
251            .group_by("id")
252            .having("id > 10")
253            .offset(10);
254        let expected = "SELECT * FROM Foo GROUP BY id HAVING id > 10 OFFSET 10";
255        test_query_builder(actual, expected);
256
257        // inner nested loop join node -> offset node -> build
258        let actual = table("Foo").select().join("Bar").offset(10);
259        let expected = "SELECT * FROM Foo JOIN Bar OFFSET 10";
260        test_query_builder(actual, expected);
261
262        // inner nested loop join node -> offset node -> build
263        let actual = table("Foo").select().join_as("Bar", "B").offset(10);
264        let expected = "SELECT * FROM Foo JOIN Bar AS B OFFSET 10";
265        test_query_builder(actual, expected);
266
267        // left outer join condition node -> offset node -> build
268        let actual = table("Foo")
269            .select()
270            .left_join("Bar")
271            .on("Foo.id = Bar.id")
272            .offset(10);
273        let expected = "SELECT * FROM Foo LEFT JOIN Bar ON Foo.id = Bar.id OFFSET 10";
274        test_query_builder(actual, expected);
275
276        // left outer join condition node -> offset node -> build
277        let actual = table("Foo")
278            .select()
279            .left_join_as("Bar", "B")
280            .on("Foo.id = B.id")
281            .offset(10);
282        let expected = "SELECT * FROM Foo LEFT JOIN Bar AS B ON Foo.id = B.id OFFSET 10";
283        test_query_builder(actual, expected);
284
285        // inner join condition node -> offset node -> build
286        let actual = table("Foo")
287            .select()
288            .join("Bar")
289            .on("Foo.id = Bar.id")
290            .offset(10);
291        let expected = "SELECT * FROM Foo JOIN Bar ON Foo.id = Bar.id OFFSET 10";
292        test_query_builder(actual, expected);
293
294        // filter node -> offset node -> build
295        let actual = table("Bar").select().filter("id > 2").offset(100);
296        let expected = "SELECT * FROM Bar WHERE id > 2 OFFSET 100";
297        test_query_builder(actual, expected);
298
299        // project node -> offset node -> build
300        let actual = table("Item").select().project("*").offset(10);
301        let expected = "SELECT * FROM Item OFFSET 10";
302        test_query_builder(actual, expected);
303
304        // inner hash join node -> offset node -> build
305        let actual = table("Player")
306            .select()
307            .join("PlayerItem")
308            .hash_executor("PlayerItem.user_id", "Player.id")
309            .offset(100)
310            .build();
311        let expected = {
312            let join = InnerJoinPlan {
313                input: InnerJoinInputPlan::Hash(HashJoinPlan {
314                    input: HashJoinInputPlan::Source(SourcePlan::Table(TableSourcePlan {
315                        name: "Player".to_owned(),
316                        alias: None,
317                        access: TableAccessPlan::FullScan,
318                    })),
319                    right: SourcePlan::Table(TableSourcePlan {
320                        name: "PlayerItem".to_owned(),
321                        alias: None,
322                        access: TableAccessPlan::FullScan,
323                    }),
324                    input_key: col("Player.id").build_expr_plan().unwrap(),
325                    right_key: col("PlayerItem.user_id").build_expr_plan().unwrap(),
326                    right_filter: None,
327                }),
328            };
329            let project = ProjectPlan {
330                input: ProjectInputPlan::InnerJoin(Box::new(join)),
331                projection: ProjectionPlan::SelectItems(
332                    SelectItemList::from("*").build_select_items_plan().unwrap(),
333                ),
334            };
335
336            let offset = OffsetPlan {
337                input: OffsetInputPlan::Project(project),
338                count: num(100).build_expr_plan().unwrap(),
339            };
340
341            Ok(StatementPlan::Query(QueryPlan::Offset(offset)))
342        };
343        assert_eq!(actual, expected);
344
345        // select -> offset -> derived subquery
346        let actual = table("Foo").select().offset(10).alias_as("Sub").select();
347        let expected = "SELECT * FROM (SELECT * FROM Foo OFFSET 10) Sub";
348        test_query_builder(actual, expected);
349    }
350}
gluesql_core/query_builder/select/offset.rs

gluesql_core/query_builder/select/
offset.rs
