uqa-sql 0.3.6

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
142
143
144
145

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

//! Rewrite stored relation, column, and literal sequence references in SQL schema expressions.
use super::walk_schema_expr_mut;
use uqa_core::{RelationIdentity, Value};

pub fn stored_relation_reference_matches(reference: &str, target: &RelationIdentity) -> bool {
    match RelationIdentity::parse_reference(reference) {
        Ok((Some(schema), name)) => schema == target.schema && name == target.name,
        Ok((None, name)) => name == target.name,
        // Corrupt legacy metadata is never evidence that a dependency is absent; DDL must not leave it dangling.
        Err(_) => true,
    }
}

pub fn upgrade_legacy_schema_function_dispatches(
    columns: &mut [crate::ast::ColumnDef],
    constraints: &mut crate::ast::TableConstraintSet,
) -> bool {
    let mut changed = false;
    for column in columns {
        for expression in [column.default.as_mut(), column.check.as_mut()]
            .into_iter()
            .flatten()
        {
            changed |= expression.upgrade_legacy_serialized_dispatches();
        }
        if let Some(generated) = &mut column.generated {
            changed |= generated.expression.upgrade_legacy_serialized_dispatches();
        }
    }
    for check in &mut constraints.checks {
        changed |= check.expr.upgrade_legacy_serialized_dispatches();
    }
    changed
}

pub fn rewrite_sequence_function_references(
    expression: &mut crate::ast::Expr,
    visit: &mut impl FnMut(&mut String) -> Result<(), String>,
) -> Result<(), String> {
    walk_schema_expr_mut(expression, &mut |node| {
        let crate::ast::Expr::Func { name, args, .. } = node else {
            return Ok(());
        };
        let lower = name.to_ascii_lowercase();
        let local = lower.strip_prefix("pg_catalog.").unwrap_or(&lower);
        if !matches!(local, "nextval" | "currval" | "setval")
            || (lower.contains('.') && !lower.starts_with("pg_catalog."))
        {
            return Ok(());
        }
        let Some(reference) = args.first_mut().and_then(regclass_literal_mut) else {
            // Dynamically computed text arguments retain late binding; literal regclass spellings identify catalog dependencies at declaration time.
            return Ok(());
        };
        visit(reference)
    })
}

fn regclass_literal_mut(expression: &mut crate::ast::Expr) -> Option<&mut String> {
    match expression {
        crate::ast::Expr::Literal(Value::Str(reference)) => Some(reference),
        crate::ast::Expr::Cast { expr, ty }
            if ty.eq_ignore_ascii_case("regclass")
                || ty.eq_ignore_ascii_case("pg_catalog.regclass") =>
        {
            regclass_literal_mut(expr)
        }
        _ => None,
    }
}

pub fn rename_schema_expr_column(
    expression: &mut crate::ast::Expr,
    from: &str,
    to: &str,
) -> Result<(), String> {
    walk_schema_expr_mut(expression, &mut |node| {
        match node {
            crate::ast::Expr::Star | crate::ast::Expr::QualifiedStar(_) => {
                return Err("schema expression contains `*` and cannot be rewritten safely".into());
            }
            crate::ast::Expr::Column(name) if name == from => *name = to.to_string(),
            crate::ast::Expr::QualifiedColumn { column, .. } if column == from => {
                *column = to.to_string();
            }
            _ => {}
        }
        Ok(())
    })
}

pub fn schema_expr_references_relation(
    expression: &crate::ast::Expr,
    target: &RelationIdentity,
) -> bool {
    let mut expression = expression.clone();
    let mut referenced = false;
    let result = walk_schema_expr_mut(&mut expression, &mut |node| {
        if let crate::ast::Expr::QualifiedColumn { qualifier, .. } = node {
            referenced |= stored_relation_reference_matches(qualifier, target);
        }
        Ok(())
    });
    result.is_err() || referenced
}

pub fn rename_schema_expr_relation(
    expression: &mut crate::ast::Expr,
    from: &RelationIdentity,
    to: &str,
) -> Result<(), String> {
    walk_schema_expr_mut(expression, &mut |node| {
        if let crate::ast::Expr::QualifiedColumn { qualifier, .. } = node {
            if stored_relation_reference_matches(qualifier, from) {
                *qualifier = to.to_string();
            }
        }
        Ok(())
    })
}

pub fn rename_schema_expr_qualified_column(
    expression: &mut crate::ast::Expr,
    table: &RelationIdentity,
    from: &str,
    to: &str,
) -> Result<(), String> {
    walk_schema_expr_mut(expression, &mut |node| {
        if let crate::ast::Expr::QualifiedColumn { qualifier, column } = node {
            if column == from && stored_relation_reference_matches(qualifier, table) {
                *column = to.to_string();
            }
        }
        Ok(())
    })
}

#[cfg(test)]
mod tests;