From 665b859645088cb8dcc01c75d28e3eadf533f093 Mon Sep 17 00:00:00 2001
From: Gregor Giesen <gregor@giesen.net>
Date: Sat, 21 Jan 2023 21:24:25 +0100
Subject: [PATCH] derive FromRow: added attribute skip for setting default
 value

---
 sqlx-macros-core/src/derives/attributes.rs | 4 ++++
 sqlx-macros-core/src/derives/row.rs        | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/sqlx-macros-core/src/derives/attributes.rs b/sqlx-macros-core/src/derives/attributes.rs
index bf3c126c..bfbc32f6 100644
--- a/sqlx-macros-core/src/derives/attributes.rs
+++ b/sqlx-macros-core/src/derives/attributes.rs
@@ -63,6 +63,7 @@ pub struct SqlxChildAttributes {
     pub default: bool,
     pub flatten: bool,
     pub try_from: Option<Type>,
+    pub skip: bool,
 }
 
 pub fn parse_container_attributes(input: &[Attribute]) -> syn::Result<SqlxContainerAttributes> {
@@ -155,6 +156,7 @@ pub fn parse_child_attributes(input: &[Attribute]) -> syn::Result<SqlxChildAttri
     let mut default = false;
     let mut try_from = None;
     let mut flatten = false;
+    let mut skip: bool = false;
 
     for attr in input.iter().filter(|a| a.path.is_ident("sqlx")) {
         let meta = attr
@@ -177,6 +179,7 @@ pub fn parse_child_attributes(input: &[Attribute]) -> syn::Result<SqlxChildAttri
                         }) if path.is_ident("try_from") => try_set!(try_from, val.parse()?, value),
                         Meta::Path(path) if path.is_ident("default") => default = true,
                         Meta::Path(path) if path.is_ident("flatten") => flatten = true,
+                        Meta::Path(path) if path.is_ident("skip") => skip = true,
                         u => fail!(u, "unexpected attribute"),
                     },
                     u => fail!(u, "unexpected attribute"),
@@ -190,6 +193,7 @@ pub fn parse_child_attributes(input: &[Attribute]) -> syn::Result<SqlxChildAttri
         default,
         flatten,
         try_from,
+        skip,
     })
 }
 
diff --git a/sqlx-macros-core/src/derives/row.rs b/sqlx-macros-core/src/derives/row.rs
index 11192b7d..41ac16ca 100644
--- a/sqlx-macros-core/src/derives/row.rs
+++ b/sqlx-macros-core/src/derives/row.rs
@@ -72,6 +72,12 @@ fn expand_derive_from_row_struct(
             let attributes = parse_child_attributes(&field.attrs).unwrap();
             let ty = &field.ty;
 
+            if attributes.skip {
+                return Some(parse_quote!(
+                    let #id: #ty = Default::default();
+                ));
+            }
+
             let expr: Expr = match (attributes.flatten, attributes.try_from) {
                 (true, None) => {
                     predicates.push(parse_quote!(#ty: ::sqlx::FromRow<#lifetime, R>));