allow slices to be passed to query!()

capture args by ref

sqlx-macros/src/database/mysql.rs

@@ -1,7 +1,7 @@
 impl_database_ext! {
     sqlx::MySql {
         bool,
-        String | &str,
+        String,
         i16,
         i32,
         i64,

sqlx-macros/src/database/postgres.rs

@@ -1,7 +1,7 @@
 impl_database_ext! {
     sqlx::Postgres {
         bool,
-        String | &str,
+        String,
         i16,
         i32,
         i64,

sqlx-macros/src/query_macros/args.rs

@@ -61,7 +61,7 @@ pub fn quote_args<DB: DatabaseExt>(
     let args = input.args.iter();
 
     Ok(quote! {
-        let args = (#(#args),*,);
+        let args = (#(&#args),*,);
         #args_check
     })
 }

src/ty_cons.rs

@@ -27,10 +27,19 @@ impl<T> TyCons<Option<&'_ T>> {
     }
 }
 
-impl<T> TyConsExt for TyCons<&'_ T> {
+// no overlap with the following impls because of the `: Sized` bound
+impl<T: Sized> TyConsExt for TyCons<&'_ T> {
     type Cons = T;
 }
 
+impl TyConsExt for TyCons<&'_ str> {
+    type Cons = String;
+}
+
+impl<T> TyConsExt for TyCons<&'_ [T]> {
+    type Cons = Vec<T>;
+}
+
 impl<T> TyConsExt for TyCons<Option<T>> {
     type Cons = T;
 }

tests/postgres-macros.rs

@@ -64,6 +64,26 @@ async fn test_query_file_as() -> sqlx::Result<()> {
     Ok(())
 }
 
+#[async_std::test]
+async fn query_by_string() -> sqlx::Result<()> {
+    let mut conn = sqlx::postgres::connect(&dotenv::var("DATABASE_URL").unwrap()).await?;
+
+    let string = "Hello, world!".to_string();
+
+    let result = sqlx::query!(
+            "SELECT * from (VALUES('Hello, world!')) strings(string)\
+             where string = $1 or string = $2",
+            string,
+            string[..]
+        )
+        .fetch_one(&mut conn)
+        .await?;
+
+    assert_eq!(result.string, string);
+
+    Ok(())
+}
+
 #[async_std::test]
 async fn test_nullable_err() -> sqlx::Result<()> {
     #[derive(Debug)]