Added "All About Updates" sqlite examples

Cargo.toml

@@ -22,6 +22,7 @@ members = [
     "examples/postgres/custom_types",
     "examples/postgres/relations",
     "examples/sqlite/all_about_inserts",
+	"examples/sqlite/all_about_updates",
     "examples/sqlite/getting_started_step_1",
     "examples/sqlite/getting_started_step_2",
     "examples/sqlite/getting_started_step_3",

examples/sqlite/all_about_updates/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "all_about_updates_sqlite"
+version = "0.1.0"
+edition = "2018"
+publish = false
+
+[dependencies]
+chrono = "0.4.26"
+diesel = { version = "2.1.0", path = "../../../diesel", features = ["sqlite", "chrono"] }
+
+[lib]
+doc = false

examples/sqlite/all_about_updates/src/lib.rs

@@ -0,0 +1,217 @@
+use chrono::NaiveDateTime;
+#[cfg(test)]
+use chrono::Utc;
+
+#[cfg(test)]
+use diesel::debug_query;
+use diesel::prelude::*;
+#[cfg(test)]
+use diesel::sqlite::Sqlite;
+
+table! {
+    posts {
+        id -> BigInt,
+        title -> Text,
+        body -> Text,
+        draft -> Bool,
+        publish_at -> Timestamp,
+        visit_count -> Integer,
+    }
+}
+
+#[derive(Queryable, Identifiable, AsChangeset)]
+pub struct Post {
+    pub id: i64,
+    pub title: String,
+    pub body: String,
+    pub draft: bool,
+    pub publish_at: NaiveDateTime,
+    pub visit_count: i32,
+}
+
+pub fn publish_all_posts(conn: &mut SqliteConnection) -> QueryResult<usize> {
+    use crate::posts::dsl::*;
+
+    diesel::update(posts).set(draft.eq(false)).execute(conn)
+}
+
+#[test]
+fn examine_sql_from_publish_all_posts() {
+    use crate::posts::dsl::*;
+
+    assert_eq!(
+        "UPDATE `posts` SET `draft` = ? -- binds: [false]",
+        debug_query(&diesel::update(posts).set(draft.eq(false))).to_string()
+    );
+}
+
+pub fn publish_pending_posts(conn: &mut SqliteConnection) -> QueryResult<usize> {
+    use crate::posts::dsl::*;
+    use diesel::dsl::now;
+
+    diesel::update(posts)
+        .filter(publish_at.lt(now))
+        .set(draft.eq(false))
+        .execute(conn)
+}
+
+#[test]
+fn examine_sql_from_publish_pending_posts() {
+    use crate::posts::dsl::*;
+    use diesel::dsl::now;
+
+    let query = diesel::update(posts)
+        .filter(publish_at.lt(now))
+        .set(draft.eq(false));
+    assert_eq!(
+        "UPDATE `posts` SET `draft` = ? \
+		 WHERE (`posts`.`publish_at` < CURRENT_TIMESTAMP) \
+         -- binds: [false]",
+        debug_query(&query).to_string()
+    );
+}
+
+pub fn publish_post(post: &Post, conn: &mut SqliteConnection) -> QueryResult<usize> {
+    diesel::update(post)
+        .set(posts::draft.eq(false))
+        .execute(conn)
+}
+
+#[test]
+fn examine_sql_from_publish_post() {
+    let now = Utc::now().naive_utc();
+
+    let post = Post {
+        id: 1,
+        title: "".into(),
+        body: "".into(),
+        draft: false,
+        publish_at: now,
+        visit_count: 0,
+    };
+    assert_eq!(
+        "UPDATE `posts` SET `draft` = ? WHERE (`posts`.`id` = ?) \
+         -- binds: [false, 1]",
+        debug_query(&diesel::update(&post).set(posts::draft.eq(false))).to_string()
+    );
+}
+
+pub fn increment_visit_counts(conn: &mut SqliteConnection) -> QueryResult<usize> {
+    use crate::posts::dsl::*;
+
+    diesel::update(posts)
+        .set(visit_count.eq(visit_count + 1))
+        .execute(conn)
+}
+
+#[test]
+fn examine_sql_from_increment_visit_counts() {
+    use crate::posts::dsl::*;
+
+    assert_eq!(
+        "UPDATE `posts` SET `visit_count` = (`posts`.`visit_count` + ?) \
+         -- binds: [1]",
+        debug_query::<Sqlite, _>(&diesel::update(posts).set(visit_count.eq(visit_count + 1)))
+            .to_string()
+    );
+}
+
+pub fn hide_everything(conn: &mut SqliteConnection) -> QueryResult<usize> {
+    use crate::posts::dsl::*;
+
+    diesel::update(posts)
+        .set((
+            title.eq("[REDACTED]"),
+            body.eq("This post has been classified"),
+        ))
+        .execute(conn)
+}
+
+#[test]
+fn examine_sql_from_hide_everything() {
+    use crate::posts::dsl::*;
+
+    let query = diesel::update(posts).set((
+        title.eq("[REDACTED]"),
+        body.eq("This post has been classified"),
+    ));
+    assert_eq!(
+        "UPDATE `posts` SET `title` = ?, `body` = ? \
+         -- binds: [\"[REDACTED]\", \"This post has been classified\"]",
+        debug_query::<Sqlite, _>(&query).to_string()
+    );
+}
+
+pub fn update_from_post_fields(post: &Post, conn: &mut SqliteConnection) -> QueryResult<usize> {
+    diesel::update(posts::table).set(post).execute(conn)
+}
+
+#[test]
+fn examine_sql_from_update_post_fields() {
+    let now = Utc::now().naive_utc();
+
+    let post = Post {
+        id: 1,
+        title: "".into(),
+        body: "".into(),
+        draft: false,
+        publish_at: now,
+        visit_count: 0,
+    };
+    let sql = format!(
+        "UPDATE `posts` SET \
+         `title` = ?, \
+         `body` = ?, \
+         `draft` = ?, \
+         `publish_at` = ?, \
+         `visit_count` = ? \
+         -- binds: [\
+         \"\", \
+         \"\", \
+         false, \
+         {now:?}, \
+         0\
+         ]"
+    );
+    assert_eq!(
+        sql,
+        debug_query(&diesel::update(posts::table).set(&post)).to_string()
+    );
+}
+
+pub fn update_with_option(conn: &mut SqliteConnection) -> QueryResult<usize> {
+    #[derive(AsChangeset)]
+    #[diesel(table_name = posts)]
+    struct PostForm<'a> {
+        title: Option<&'a str>,
+        body: Option<&'a str>,
+    }
+
+    diesel::update(posts::table)
+        .set(&PostForm {
+            title: None,
+            body: Some("My new post"),
+        })
+        .execute(conn)
+}
+
+#[test]
+fn examine_sql_from_update_with_option() {
+    #[derive(AsChangeset)]
+    #[diesel(table_name = posts)]
+    struct PostForm<'a> {
+        title: Option<&'a str>,
+        body: Option<&'a str>,
+    }
+
+    let post_form = PostForm {
+        title: None,
+        body: Some("My new post"),
+    };
+    let query = diesel::update(posts::table).set(&post_form);
+    assert_eq!(
+        "UPDATE `posts` SET `body` = ? \
+         -- binds: [\"My new post\"]",
+        debug_query::<Sqlite, _>(&query).to_string()
+    );
+}