Update schema dot command to show virtual tables

Cargo.lock

@@ -1687,6 +1687,7 @@ dependencies = [
 name = "limbo_kv"
 version = "0.0.14"
 dependencies = [
+ "lazy_static",
  "limbo_ext",
  "mimalloc",
 ]

cli/app.rs

@@ -765,11 +765,11 @@ impl<'a> Limbo<'a> {
     fn display_schema(&mut self, table: Option<&str>) -> anyhow::Result<()> {
         let sql = match table {
         Some(table_name) => format!(
-            "SELECT sql FROM sqlite_schema WHERE type IN ('table', 'index') AND tbl_name = '{}' AND name NOT LIKE 'sqlite_%'",
+            "SELECT sql FROM sqlite_schema WHERE type IN ('table', 'index', 'virtual') AND tbl_name = '{}' AND name NOT LIKE 'sqlite_%'",
             table_name
         ),
         None => String::from(
-            "SELECT sql FROM sqlite_schema WHERE type IN ('table', 'index') AND name NOT LIKE 'sqlite_%'"
+            "SELECT sql FROM sqlite_schema WHERE type IN ('table', 'index', 'virtual') AND name NOT LIKE 'sqlite_%'"
         ),
     };
 

core/lib.rs

@@ -556,7 +556,6 @@ impl VirtualTable {
             }
         }
         let mut parser = Parser::new(schema.as_bytes());
-        parser.reset(schema.as_bytes());
         if let ast::Cmd::Stmt(ast::Stmt::CreateTable { body, .. }) = parser.next()?.ok_or(
             LimboError::ParseError("Failed to parse schema from virtual table module".to_string()),
         )? {

core/translate/insert.rs

@@ -122,7 +122,7 @@ pub fn translate_insert(
 
     let inserting_multiple_rows = values.len() > 1;
 
-    // multiple rows - use coroutine for value population
+    // Multiple rows - use coroutine for value population
     if inserting_multiple_rows {
         let yield_reg = program.alloc_register();
         let jump_on_definition_label = program.allocate_label();
@@ -475,10 +475,9 @@ fn translate_virtual_table_insert(
         translate_expr(program, None, expr, value_registers_start + i, resolver)?;
     }
     /* *
-     * Inserts for virtual tables are done in a single step. The rowid is not provided by the user, but is generated by the
-     * vtable implementation.
-     * argv[0] = current_rowid (NULL for insert)
-     * argv[1] = insert_rowid (NULL for insert)
+     * Inserts for virtual tables are done in a single step.
+     * argv[0] = (NULL for insert)
+     * argv[1] = (NULL for insert)
      * argv[2..] = column values
      * */
 

core/translate/mod.rs

@@ -625,10 +625,14 @@ fn translate_create_virtual_table(
 
     let args_reg = if !args_vec.is_empty() {
         let args_start = program.alloc_register();
+
+        // Emit string8 instructions for each arg
         for (i, arg) in args_vec.iter().enumerate() {
             program.emit_string8(arg.clone(), args_start + i);
         }
         let args_record_reg = program.alloc_register();
+
+        // VCreate expects an array of args as a record
         program.emit_insn(Insn::MakeRecord {
             start_reg: args_start,
             count: args_vec.len(),

core/vdbe/mod.rs

@@ -988,13 +988,11 @@ impl Program {
                             )));
                         }
                     }
-                    // argv[0] = current_rowid (for DELETE if applicable)
-                    // argv[1] = insert_rowid (for INSERT if applicable)
-                    // argv[2..] = column values
                     let result = virtual_table.update(&argv);
                     match result {
                         Ok(Some(new_rowid)) => {
                             if *conflict_action == 5 {
+                                // ResolveType::Replace
                                 if let Some(conn) = self.connection.upgrade() {
                                     conn.update_last_rowid(new_rowid as u64);
                                 }

extensions/core/README.md

@@ -169,7 +169,11 @@ impl VTabModule for CsvVTable {
     /// Declare the name for your virtual table
     const NAME: &'static str = "csv_data";
 
-    fn init_sql() -> &'static str {
+    /// Declare the type of vtable (TableValuedFunction or VirtualTable)
+    const VTAB_KIND: VTabKind = VTabKind::VirtualTable;
+
+    /// Function to initialize the schema of your vtable 
+    fn create_schema(_args: &[Value]) -> &'static str {
         "CREATE TABLE csv_data(
             name TEXT,
             age TEXT,
@@ -178,7 +182,7 @@ impl VTabModule for CsvVTable {
     }
 
     /// Open to return a new cursor: In this simple example, the CSV file is read completely into memory on connect.
-    fn open() -> Result<Self::VCursor, Self::Error> {
+    fn open(&self) -> Result<Self::VCursor, Self::Error> {
         // Read CSV file contents from "data.csv"
         let csv_content = fs::read_to_string("data.csv").unwrap_or_default();
         // For simplicity, we'll ignore the header row.
@@ -195,7 +199,7 @@ impl VTabModule for CsvVTable {
     }
 
     /// Filter through result columns. (not used in this simple example)
-    fn filter(_cursor: &mut Self::VCursor, _arg_count: i32, _args: &[Value]) -> ResultCode {
+    fn filter(_cursor: &mut Self::VCursor, _args: &[Value]) -> ResultCode {
         ResultCode::OK
     }
 
@@ -218,6 +222,22 @@ impl VTabModule for CsvVTable {
     fn eof(cursor: &Self::VCursor) -> bool {
         cursor.index >= cursor.rows.len()
     }
+
+    /// *Optional* methods for non-readonly tables
+
+    /// Update the value at rowid
+    fn update(&mut self, _rowid: i64, _args: &[Value]) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    /// Insert the value(s)
+    fn insert(&mut self, _args: &[Value]) -> Result<i64, Self::Error> {
+        Ok(0)
+    }
+    /// Delete the value at rowid
+    fn delete(&mut self, _rowid: i64) -> Result<(), Self::Error> {
+        Ok(())
+    }
 }
 
 /// The cursor for iterating over CSV rows.