uqa_sql/schema/
removal.rs

1//
2// Unified Query Algebra
3//
4// Copyright (c) 2023-2026 Cognica, Inc.
5//
6
7//! DROP relation target binding and label protection.
8use crate::{ast::DropKind, catalog::resolution::RelationResolution, SQLError};
9
10pub trait RelationDropCatalog {
11    fn resolve_relation_kind(&self, name: &str) -> Result<RelationResolution, SQLError>;
12    fn resolve_age_label_relation_name(&self, name: &str) -> Result<Option<String>, SQLError>;
13}
14pub fn validate_drop_table_label_target(
15    catalog: &dyn RelationDropCatalog,
16    name: &str,
17) -> Result<(), SQLError> {
18    if let Some(canonical) = catalog.resolve_age_label_relation_name(name)? {
19        let relation =
20            uqa_core::RelationIdentity::from_legacy_name(&canonical).map_err(|error| {
21                SQLError::Internal(format!(
22                    "resolve AGE label relation `{canonical}` for DROP TABLE: {error}"
23                ))
24            })?;
25        return Err(SQLError::Routine {
26            sqlstate: "2BP01".into(),
27            message: format!(
28                "table \"{}\" is for label \"{}\"",
29                relation.name, relation.name
30            ),
31        });
32    }
33    Ok(())
34}
35
36pub fn drop_relation_kind(kind: DropKind) -> &'static str {
37    match kind {
38        DropKind::Table => "table",
39        DropKind::ForeignTable => "foreign table",
40        DropKind::ForeignServer => "server",
41        DropKind::ForeignWrapper => "foreign-data wrapper",
42        DropKind::View => "view",
43        DropKind::MaterializedView => "materialized view",
44        DropKind::Sequence => "sequence",
45        DropKind::Index => "index",
46        DropKind::Schema => "schema",
47        DropKind::Domain => "domain",
48        DropKind::Type => "type",
49    }
50}
51
52/// `DropErrorMsgWrongType`: a DROP names a relation of another kind, and the hint names the command that drops the kind it is.
53pub fn wrong_drop_kind_error(local: &str, expected: &str, found: &str) -> SQLError {
54    let article = if expected == "index" { "an" } else { "a" };
55    let hint = match found {
56        "table" => Some("Use DROP TABLE to remove a table."),
57        "sequence" => Some("Use DROP SEQUENCE to remove a sequence."),
58        "view" => Some("Use DROP VIEW to remove a view."),
59        "materialized view" => Some("Use DROP MATERIALIZED VIEW to remove a materialized view."),
60        "index" => Some("Use DROP INDEX to remove an index."),
61        "foreign table" => Some("Use DROP FOREIGN TABLE to remove a foreign table."),
62        "type" | "composite type" => Some("Use DROP TYPE to remove a type."),
63        _ => None,
64    };
65    SQLError::Diagnostic {
66        sqlstate: "42809".into(),
67        message: format!("\"{local}\" is not {article} {expected}"),
68        detail: None,
69        hint: hint.map(str::to_string),
70    }
71}
72
73/// Resolve one requested name so execution can repeat the same policy after a lock wait.
74pub fn bind_relation_drop_target(
75    catalog: &dyn RelationDropCatalog,
76    name: &str,
77    kind: DropKind,
78    if_exists: bool,
79    notice: &mut dyn FnMut(&str),
80) -> Result<Option<String>, SQLError> {
81    if kind == DropKind::Table {
82        validate_drop_table_label_target(catalog, name)?;
83    }
84    let expected = drop_relation_kind(kind);
85    let (_, local) =
86        uqa_core::RelationIdentity::parse_reference(name).map_err(SQLError::Internal)?;
87    match catalog.resolve_relation_kind(name)? {
88        RelationResolution::Found(canonical, found) if found == expected => Ok(Some(canonical)),
89        RelationResolution::Found(_, found) => Err(wrong_drop_kind_error(&local, expected, found)),
90        RelationResolution::MissingSchema(schema) if if_exists => {
91            notice(&format!("schema \"{schema}\" does not exist, skipping"));
92            Ok(None)
93        }
94        RelationResolution::MissingRelation if if_exists => {
95            notice(&format!("{expected} \"{local}\" does not exist, skipping"));
96            Ok(None)
97        }
98        RelationResolution::MissingSchema(schema) => Err(SQLError::Routine {
99            sqlstate: "3F000".into(),
100            message: format!("schema \"{schema}\" does not exist"),
101        }),
102        RelationResolution::MissingRelation => Err(SQLError::Routine {
103            sqlstate: if matches!(kind, DropKind::ForeignTable | DropKind::Index) {
104                "42704"
105            } else {
106                "42P01"
107            }
108            .into(),
109            message: format!("{expected} \"{local}\" does not exist"),
110        }),
111    }
112}
113
114pub mod hierarchy;
115pub mod tables;
116
117#[cfg(test)]
118mod tests;
uqa_sql/schema/removal.rs

uqa_sql/schema/
removal.rs
