From f2163337d5bbd410eec613f9efa6355fffb7a599 Mon Sep 17 00:00:00 2001
From: Meghan Denny <hello@nektro.net>
Date: Sun, 9 Aug 2026 16:34:53 -0700
Subject: [PATCH] add support for columns that foreign keys

---
 src/lib.zig        | 12 ++++++++++++
 src/postgresql.zig | 11 +++++++++++
 src/sqlite3.zig    |  6 ++++++
 3 files changed, 29 insertions(+)

diff --git a/src/lib.zig b/src/lib.zig
index f74f4330c9ae08df23f5d963261bf19c4011ebfa..fca69f388bd400263e4546fadbc56dc204d25545 100644
--- a/src/lib.zig
+++ b/src/lib.zig
@@ -86,8 +86,20 @@ pub const Engine = union(DriverType) {
     }
 
     pub fn addColumn(engine: *Engine, alloc: std.mem.Allocator, comptime table_name: []const u8, comptime col_name: []const u8, T: type) !void {
+        if (switch (@typeInfo(T)) {
+            .@"struct", .@"enum", .@"union" => @hasDecl(T, "foreign_table"),
+            else => false,
+        }) {
+            return addColumnForeign(engine, alloc, table_name, col_name, T, T.foreign_table, T.foreign_column);
+        }
         return switch (engine.*) {
             inline else => |*e| e.addColumn(alloc, table_name, col_name, T),
         };
     }
+
+    pub fn addColumnForeign(engine: *Engine, alloc: std.mem.Allocator, comptime table_name: []const u8, comptime col_name: []const u8, T: type, comptime table_name2: []const u8, comptime col_name2: []const u8) !void {
+        return switch (engine.*) {
+            inline else => |*e| e.addColumnForeign(alloc, table_name, col_name, T, table_name2, col_name2),
+        };
+    }
 };
diff --git a/src/postgresql.zig b/src/postgresql.zig
index 26506964778e166bf95800b0df88e6c4e8af64f9..3dedd1dc0559acc5f5ad02c15d3d6de925d650a7 100644
--- a/src/postgresql.zig
+++ b/src/postgresql.zig
@@ -284,6 +284,17 @@ pub fn addColumn(driver: *Driver, alloc: std.mem.Allocator, comptime table_name:
     @panic("TODO");
 }
 
+pub fn addColumnForeign(driver: *Driver, alloc: std.mem.Allocator, comptime table_name: []const u8, comptime col_name: []const u8, T: type, comptime table_name2: []const u8, comptime col_name2: []const u8) !void {
+    _ = driver;
+    _ = alloc;
+    _ = table_name;
+    _ = col_name;
+    _ = T;
+    _ = table_name2;
+    _ = col_name2;
+    @panic("TODO");
+}
+
 pub fn nameForType(T: type) []const u8 {
     if (@typeInfo(T) == .optional) {
         return nameForType2(T);
diff --git a/src/sqlite3.zig b/src/sqlite3.zig
index 9a4f119b0efec1254064c3bf00cc26d0b8fa45ec..36c255818905970cc85a784729e8c0392b235718 100644
--- a/src/sqlite3.zig
+++ b/src/sqlite3.zig
@@ -107,6 +107,12 @@ pub fn addColumn(self: *Self, alloc: std.mem.Allocator, comptime table_name: []c
     try self.exec(alloc, comptime std.fmt.comptimePrint("alter table {s} add \"{s}\" {s}", .{ table_name, col_name, nameForType(T) }), .{});
 }
 
+pub fn addColumnForeign(self: *Self, alloc: std.mem.Allocator, comptime table_name: []const u8, comptime col_name: []const u8, T: type, comptime table_name2: []const u8, comptime col_name2: []const u8) !void {
+    const t = tracer.trace(@src(), " {s}.{s}", .{ table_name, col_name });
+    defer t.end();
+    try self.exec(alloc, comptime std.fmt.comptimePrint("alter table {s} add \"{s}\" {s} references \"{s}\" (\"{s}\")", .{ table_name, col_name, nameForType(T), table_name2, col_name2 }), .{});
+}
+
 pub fn nameForType(T: type) []const u8 {
     if (@typeInfo(T) == .optional) {
         return nameForType2(@typeInfo(T).optional.child);
-- 
2.54.0