From e3217d0cda0458090102e0bf4e1864b12176c735 Mon Sep 17 00:00:00 2001
From: Billy Chan <ccw.billy.123@gmail.com>
Date: Sat, 21 Jan 2023 15:23:55 +0800
Subject: [PATCH 1/4] Added `QueryTrait::maybe`

---
 src/query/traits.rs | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/query/traits.rs b/src/query/traits.rs
index cfc35350d..4015a7733 100644
--- a/src/query/traits.rs
+++ b/src/query/traits.rs
@@ -23,4 +23,49 @@ pub trait QueryTrait {
             self.as_query().build_any(query_builder.as_ref()),
         )
     }
+
+    /// Perform some operations on the [QueryTrait::QueryStatement] with the given `Option<T>` value
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use sea_orm::{entity::*, query::*, tests_cfg::cake, DbBackend};
+    ///
+    /// assert_eq!(
+    ///     cake::Entity::find()
+    ///         .select_only()
+    ///         // Select column
+    ///         .maybe(cake::Column::Id, |mut query, column| {
+    ///             if let Some(col) = column.into() {
+    ///                 query = query.column_as(col.count(), "count");
+    ///             }
+    ///             query
+    ///         })
+    ///         // Limit result to the first 100 rows
+    ///         .maybe(Some(100), |mut query, limit| {
+    ///             if let Some(n) = limit.into() {
+    ///                 query = query.limit(n);
+    ///             }
+    ///             query
+    ///         })
+    ///         // Do nothing
+    ///         .maybe(None, |mut query, offset| {
+    ///             if let Some(n) = offset.into() {
+    ///                 query = query.offset(n);
+    ///             }
+    ///             query
+    ///         })
+    ///         .build(DbBackend::Postgres)
+    ///         .to_string(),
+    ///     r#"SELECT COUNT("cake"."id") AS "count" FROM "cake" LIMIT 100"#
+    /// );
+    /// ```
+    fn maybe<T, F>(self, val: T, if_some: F) -> Self
+    where
+        Self: Sized,
+        T: Into<Option<T>>,
+        F: FnOnce(Self, T) -> Self,
+    {
+        if_some(self, val)
+    }
 }

From eed3355b0c7a1a3dd6c1462f5d1b98517a618786 Mon Sep 17 00:00:00 2001
From: Chris Tsang <chris.2y3@outlook.com>
Date: Wed, 25 Jan 2023 14:21:35 +0800
Subject: [PATCH 2/4] Make the API better

---
 src/query/traits.rs | 36 +++++++++++-------------------------
 1 file changed, 11 insertions(+), 25 deletions(-)

diff --git a/src/query/traits.rs b/src/query/traits.rs
index 4015a7733..69b5d7659 100644
--- a/src/query/traits.rs
+++ b/src/query/traits.rs
@@ -33,39 +33,25 @@ pub trait QueryTrait {
     ///
     /// assert_eq!(
     ///     cake::Entity::find()
-    ///         .select_only()
-    ///         // Select column
-    ///         .maybe(cake::Column::Id, |mut query, column| {
-    ///             if let Some(col) = column.into() {
-    ///                 query = query.column_as(col.count(), "count");
-    ///             }
-    ///             query
-    ///         })
-    ///         // Limit result to the first 100 rows
-    ///         .maybe(Some(100), |mut query, limit| {
-    ///             if let Some(n) = limit.into() {
-    ///                 query = query.limit(n);
-    ///             }
-    ///             query
-    ///         })
-    ///         // Do nothing
-    ///         .maybe(None, |mut query, offset| {
-    ///             if let Some(n) = offset.into() {
-    ///                 query = query.offset(n);
-    ///             }
-    ///             query
+    ///         .apply_if(Some(3), |mut query, v| {
+    ///             query.filter(cake::Column::Id.eq(v))
     ///         })
+    ///         .apply_if(Some(100), QuerySelect::limit)
+    ///         .apply_if(None, QuerySelect::offset) // no-op
     ///         .build(DbBackend::Postgres)
     ///         .to_string(),
-    ///     r#"SELECT COUNT("cake"."id") AS "count" FROM "cake" LIMIT 100"#
+    ///     r#"SELECT "cake"."id", "cake"."name" FROM "cake" WHERE "cake"."id" = 3 LIMIT 100"#
     /// );
     /// ```
-    fn maybe<T, F>(self, val: T, if_some: F) -> Self
+    fn apply_if<T, F>(self, val: Option<T>, if_some: F) -> Self
     where
         Self: Sized,
-        T: Into<Option<T>>,
         F: FnOnce(Self, T) -> Self,
     {
-        if_some(self, val)
+        if let Some(val) = val {
+            if_some(self, val)
+        } else {
+            self
+        }
     }
 }

From d4fc1530d7ae1f1bde927c46c432590438f63b52 Mon Sep 17 00:00:00 2001
From: Chris Tsang <chris.2y3@outlook.com>
Date: Wed, 25 Jan 2023 14:24:03 +0800
Subject: [PATCH 3/4] Docs

---
 src/query/traits.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/query/traits.rs b/src/query/traits.rs
index 69b5d7659..821392471 100644
--- a/src/query/traits.rs
+++ b/src/query/traits.rs
@@ -24,7 +24,7 @@ pub trait QueryTrait {
         )
     }
 
-    /// Perform some operations on the [QueryTrait::QueryStatement] with the given `Option<T>` value
+    /// Apply a operation on the [QueryTrait::QueryStatement] if the given `Option<T>` is `Some(_)`
     ///
     /// # Example
     ///

From 301e85647d5b716265363a83c1c50954cf2151c4 Mon Sep 17 00:00:00 2001
From: Chris Tsang <chris.2y3@outlook.com>
Date: Thu, 26 Jan 2023 16:52:55 +0800
Subject: [PATCH 4/4] Update src/query/traits.rs

---
 src/query/traits.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/query/traits.rs b/src/query/traits.rs
index 821392471..2dd30d564 100644
--- a/src/query/traits.rs
+++ b/src/query/traits.rs
@@ -24,7 +24,7 @@ pub trait QueryTrait {
         )
     }
 
-    /// Apply a operation on the [QueryTrait::QueryStatement] if the given `Option<T>` is `Some(_)`
+    /// Apply an operation on the [QueryTrait::QueryStatement] if the given `Option<T>` is `Some(_)`
     ///
     /// # Example
     ///