From 6f1d03d64dfae8cf3d302ba4f353046d6ba9694c Mon Sep 17 00:00:00 2001
From: Pekka Enberg <penberg@iki.fi>
Date: Sun, 27 Aug 2023 21:18:17 +0300
Subject: [PATCH] Look up columns from table schema

---
 core/schema.rs |  4 ++--
 core/vdbe.rs   | 27 +++++++++++++++++++++------
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/core/schema.rs b/core/schema.rs
index 037c5e202..916dab934 100644
--- a/core/schema.rs
+++ b/core/schema.rs
@@ -45,8 +45,8 @@ impl Table {
 }
 
 pub struct Column {
-    name: String,
-    ty: Type,
+    pub name: String,
+    pub ty: Type,
 }
 
 pub enum Type {
diff --git a/core/vdbe.rs b/core/vdbe.rs
index 2d7fb1db5..7b01f2b38 100644
--- a/core/vdbe.rs
+++ b/core/vdbe.rs
@@ -11,7 +11,7 @@ pub enum Insn {
     OpenReadAwait,
     RewindAsync,
     RewindAwait(RewindAwaitInsn),
-    Column,
+    Column(ColumnInsn),
     ResultRow,
     NextAsync,
     NextAwait,
@@ -31,6 +31,10 @@ pub struct RewindAwaitInsn {
     pub pc_if_empty: usize,
 }
 
+pub struct ColumnInsn {
+    pub column: usize,
+}
+
 pub struct GotoInsn {
     pub target_pc: usize,
 }
@@ -104,7 +108,7 @@ impl Program {
                     // TODO: Check if empty
                     self.pc = rewind_await.pc_if_empty;
                 }
-                Insn::Column => {
+                Insn::Column(_) => {
                     self.pc += 1;
                 }
                 Insn::ResultRow => {
@@ -140,7 +144,9 @@ pub fn translate(schema: &Schema, stmt: Stmt) -> Result<Program> {
 fn translate_select(schema: &Schema, select: Select) -> Result<Program> {
     match select.body.select {
         OneSelect::Select {
-            from: Some(from), ..
+            columns,
+            from: Some(from),
+            ..
         } => {
             let table_name = match from.select {
                 Some(select_table) => match *select_table {
@@ -162,8 +168,17 @@ fn translate_select(schema: &Schema, select: Select) -> Result<Program> {
             program.emit_insn(Insn::OpenReadAwait);
             program.emit_insn(Insn::RewindAsync);
             let rewind_await_offset = program.emit_placeholder();
-            program.emit_insn(Insn::Column);
-            program.emit_insn(Insn::Column);
+            for col in columns {
+                match col {
+                    sqlite3_parser::ast::ResultColumn::Expr(_, _) => todo!(),
+                    sqlite3_parser::ast::ResultColumn::Star => {
+                        for i in 0..table.columns.len() {
+                            program.emit_insn(Insn::Column(ColumnInsn { column: i }));
+                        }
+                    }
+                    sqlite3_parser::ast::ResultColumn::TableStar(_) => todo!(),
+                }
+            }
             program.emit_insn(Insn::ResultRow);
             program.emit_insn(Insn::NextAsync);
             program.emit_insn(Insn::NextAwait);
@@ -221,7 +236,7 @@ fn print_insn(addr: usize, insn: &Insn) {
             0,
             "".to_string(),
         ),
-        Insn::Column => ("Column", 0, 0, 0, "", 0, "".to_string()),
+        Insn::Column(column) => ("Column", 0, column.column, 0, "", 0, "".to_string()),
         Insn::ResultRow => ("ResultRow", 0, 0, 0, "", 0, "".to_string()),
         Insn::NextAsync => ("NextAsync", 0, 0, 0, "", 0, "".to_string()),
         Insn::NextAwait => ("NextAwait", 0, 0, 0, "", 0, "".to_string()),