fraiseql_db/
introspector.rs

1//! Database introspection trait for querying table metadata.
2
3use fraiseql_error::Result;
4
5use crate::DatabaseType;
6
7/// Kind of database relation (table or view).
8#[derive(Debug, Clone, PartialEq, Eq)]
9pub enum RelationKind {
10    /// A base table.
11    Table,
12    /// A view.
13    View,
14}
15
16/// Metadata about a database relation (table or view).
17#[derive(Debug, Clone, PartialEq, Eq)]
18pub struct RelationInfo {
19    /// Schema name (e.g. "public", "main", "dbo").
20    pub schema: String,
21    /// Relation name.
22    pub name:   String,
23    /// Whether the relation is a table or view.
24    pub kind:   RelationKind,
25}
26
27/// Database introspection trait for querying table metadata.
28#[allow(async_fn_in_trait)] // Reason: trait is used with concrete types only, not dyn Trait
29pub trait DatabaseIntrospector: Send + Sync {
30    /// List all fact tables in the database (tables starting with "tf_").
31    ///
32    /// Returns: Vec of table names matching the tf_* pattern
33    async fn list_fact_tables(&self) -> Result<Vec<String>>;
34
35    /// Query column information for a table.
36    ///
37    /// Returns: Vec of (column_name, data_type, is_nullable)
38    async fn get_columns(&self, table_name: &str) -> Result<Vec<(String, String, bool)>>;
39
40    /// Query indexes for a table.
41    ///
42    /// Returns: Vec of column names that have indexes
43    async fn get_indexed_columns(&self, table_name: &str) -> Result<Vec<String>>;
44
45    /// Get database type (for SQL type parsing).
46    fn database_type(&self) -> DatabaseType;
47
48    /// Get sample JSONB data from a column to extract dimension paths.
49    ///
50    /// Returns: Sample JSON value from the column, or None if no data exists.
51    async fn get_sample_jsonb(
52        &self,
53        _table_name: &str,
54        _column_name: &str,
55    ) -> Result<Option<serde_json::Value>> {
56        Ok(None)
57    }
58
59    /// List all relations (tables and views) in the database.
60    ///
61    /// Returns: Vec of relation metadata. Default implementation returns an empty list.
62    async fn list_relations(&self) -> Result<Vec<RelationInfo>> {
63        Ok(Vec::new())
64    }
65
66    /// Get sample JSON rows from a column for schema inference.
67    ///
68    /// Returns: Vec of parsed JSON values from the column. Default returns an empty list.
69    async fn get_sample_json_rows(
70        &self,
71        _table_name: &str,
72        _column_name: &str,
73        _limit: usize,
74    ) -> Result<Vec<serde_json::Value>> {
75        Ok(Vec::new())
76    }
77}
fraiseql_db/introspector.rs

fraiseql_db/
introspector.rs
