db_migrate/
schema.rs

1// This module is for future schema introspection and drift detection
2// Currently contains placeholder implementations that can be extended
3
4use crate::MigrationError;
5use scylla::Session;
6use serde::{Deserialize, Serialize};
7
8#[derive(Debug, Clone, Serialize, Deserialize)]
9pub struct TableInfo {
10    pub keyspace: String,
11    pub table_name: String,
12    pub columns: Vec<ColumnInfo>,
13    pub primary_key: Vec<String>,
14}
15
16#[derive(Debug, Clone, Serialize, Deserialize)]
17pub struct ColumnInfo {
18    pub name: String,
19    pub data_type: String,
20    pub kind: String, // partition_key, clustering, regular
21}
22
23#[derive(Debug, Clone, Serialize, Deserialize)]
24pub struct IndexInfo {
25    pub name: String,
26    pub table_name: String,
27    pub column_name: String,
28    pub index_type: String,
29}
30
31pub struct SchemaIntrospector<'a> {
32    session: &'a Session,
33    keyspace: &'a str,
34}
35
36impl<'a> SchemaIntrospector<'a> {
37    pub fn new(session: &'a Session, keyspace: &'a str) -> Self {
38        Self { session, keyspace }
39    }
40
41    /// Get all tables in the current keyspace
42    pub async fn get_tables(&self) -> Result<Vec<TableInfo>, MigrationError> {
43        // This is a placeholder implementation
44        // In a full implementation, you would query system.schema_columns
45        // and system.schema_keyspaces to get the actual schema information
46
47        let query = "SELECT table_name FROM system_schema.tables WHERE keyspace_name = ?";
48        let rows = self.session.query(query, (self.keyspace,)).await?;
49
50        let mut tables = Vec::new();
51        for row in rows
52            .rows_typed::<(String,)>()
53            .map_err(|e| MigrationError::IntegrityError(e.to_string()))?
54        {
55            let (table_name,) = row.map_err(|e| MigrationError::IntegrityError(e.to_string()))?;
56
57            // For now, just return basic table info
58            // In a full implementation, you'd fetch column details
59            tables.push(TableInfo {
60                keyspace: self.keyspace.to_string(),
61                table_name,
62                columns: Vec::new(),     // TODO: Implement column introspection
63                primary_key: Vec::new(), // TODO: Implement primary key detection
64            });
65        }
66
67        Ok(tables)
68    }
69
70    /// Get all indexes in the current keyspace
71    pub async fn get_indexes(&self) -> Result<Vec<IndexInfo>, MigrationError> {
72        // Placeholder implementation
73        // In a full implementation, you would query system.schema_columns
74        // to find secondary indexes
75
76        Ok(Vec::new()) // TODO: Implement index introspection
77    }
78
79    /// Compare current schema with expected schema
80    pub async fn detect_schema_drift(
81        &self,
82        _expected_schema: &[TableInfo],
83    ) -> Result<Vec<String>, MigrationError> {
84        // Placeholder for schema drift detection
85        // This would compare the current database schema with what's expected
86        // based on the applied migrations
87
88        Ok(Vec::new()) // TODO: Implement drift detection
89    }
90}
91
92// Future features that could be implemented:
93// - Full CQL schema parsing and comparison
94// - Detection of manual schema changes outside of migrations
95// - Schema validation against migration files
96// - Automatic schema documentation generation
97// - Schema export/import functionality
db_migrate/schema.rs

db_migrate/
schema.rs
