uqa-sql 0.3.5

PostgreSQL-compatible SQL compiler built on libpg_query
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141

//
// Unified Query Algebra
//
// Copyright (c) 2023-2026 Cognica, Inc.
//

//! Relation namespace inputs for static SQL analysis.

use crate::SQLError;

/// Immutable session inputs used to resolve unqualified relation names during one statement.
#[derive(Clone)]
pub struct RelationNameResolution {
    pub search_path: Vec<String>,
    pub temporary_schema: String,
    pub temporary_namespace_allocated: bool,
    pub current_user: String,
    pub lookup_mode: RelationLookupMode,
}

/// Whether a query resolves session-visible names or follows catalog identities captured when a stored expression was defined.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum RelationLookupMode {
    Dynamic,
    Bound,
}

impl RelationNameResolution {
    pub fn search_path(&self) -> &[String] {
        &self.search_path
    }

    pub fn search_path_contains(&self, schema: &str) -> bool {
        self.search_path.iter().any(|candidate| candidate == schema)
    }

    pub fn current_user(&self) -> &str {
        &self.current_user
    }

    pub fn lookup_mode(&self) -> RelationLookupMode {
        self.lookup_mode
    }

    pub fn qualified_schema(&self, name: &str) -> Result<Option<(String, String)>, SQLError> {
        let (schema, _) = uqa_core::RelationIdentity::parse_reference(name).map_err(|error| {
            SQLError::Internal(format!("resolve catalog relation `{name}`: {error}"))
        })?;
        Ok(schema.map(|schema| {
            let resolved = if schema == "pg_temp" {
                self.temporary_schema.clone()
            } else {
                schema.clone()
            };
            (schema, resolved)
        }))
    }

    pub fn set_lookup_mode(&mut self, lookup_mode: RelationLookupMode) -> RelationLookupMode {
        std::mem::replace(&mut self.lookup_mode, lookup_mode)
    }

    pub fn raw_relation_lookup_candidates(
        &self,
        name: &str,
    ) -> Result<Vec<uqa_core::RelationIdentity>, SQLError> {
        let (schema, relation) =
            uqa_core::RelationIdentity::parse_reference(name).map_err(|error| {
                SQLError::Internal(format!("resolve catalog relation `{name}`: {error}"))
            })?;
        if let Some(schema) = schema {
            let schema = if schema == "pg_temp" {
                self.temporary_schema.clone()
            } else {
                schema
            };
            return Ok(vec![uqa_core::RelationIdentity::new(schema, relation)]);
        }
        let mut candidates = vec![uqa_core::RelationIdentity::new(
            &self.temporary_schema,
            &relation,
        )];
        candidates.extend(
            self.search_path
                .iter()
                .filter(|schema| *schema != "pg_catalog" && *schema != "information_schema")
                .map(|schema| uqa_core::RelationIdentity::new(schema, &relation)),
        );
        Ok(candidates)
    }
}

/// Complete outcome of resolving one relation reference through a statement namespace.
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum RelationResolution {
    Found(String, &'static str),
    MissingRelation,
    MissingSchema(String),
}

impl RelationResolution {
    /// Collapse namespace absence only for SQL boundaries whose contract reports an undefined relation for either absence outcome.
    pub fn into_found(self) -> Option<(String, &'static str)> {
        match self {
            Self::Found(name, kind) => Some((name, kind)),
            Self::MissingRelation | Self::MissingSchema(_) => None,
        }
    }
}

/// Bind rename-source diagnostics without losing the distinction between missing schemas and relations.
pub fn resolve_relation_rename_source(
    resolution: RelationResolution,
    name: &str,
    if_exists: bool,
    notice: &mut dyn FnMut(&str),
) -> Result<Option<(String, &'static str)>, crate::SQLError> {
    match resolution {
        RelationResolution::Found(canonical, kind) => Ok(Some((canonical, kind))),
        RelationResolution::MissingSchema(_) | RelationResolution::MissingRelation if if_exists => {
            let (_, local_name) = uqa_core::RelationIdentity::parse_reference(name)
                .map_err(crate::SQLError::Internal)?;
            notice(&format!(
                "relation \"{local_name}\" does not exist, skipping"
            ));
            Ok(None)
        }
        RelationResolution::MissingSchema(schema) => Err(crate::SQLError::Routine {
            sqlstate: "3F000".into(),
            message: format!("schema \"{schema}\" does not exist"),
        }),
        RelationResolution::MissingRelation => Err(crate::SQLError::Routine {
            sqlstate: "42P01".into(),
            message: format!("relation \"{name}\" does not exist"),
        }),
    }
}

pub mod candidates;

pub mod creation;