feat: better database errors (#2109)

* feat(core): create error kind enum

* feat(core): add error kind for postgres

* feat(core): add error kind for sqlite

* feat(core): add error kind for mysql

* test(postgres): add error tests

* test(sqlite): add error tests

* test(mysql): add error tests

* fix(tests): fix tests rebasing

* refac(errors): add `ErrorKind::Other` variant

tests/sqlite/error.rs

@@ -0,0 +1,72 @@
+use sqlx::{error::ErrorKind, query, sqlite::Sqlite, Connection, Executor, Transaction};
+use sqlx_test::new;
+
+#[sqlx_macros::test]
+async fn it_fails_with_unique_violation() -> anyhow::Result<()> {
+    let mut conn = new::<Sqlite>().await?;
+    let mut tx = conn.begin().await?;
+
+    let res: Result<_, sqlx::Error> = sqlx::query("INSERT INTO tweet VALUES (1, 'Foo', true, 1);")
+        .execute(&mut *tx)
+        .await;
+    let err = res.unwrap_err();
+
+    let err = err.into_database_error().unwrap();
+
+    assert_eq!(err.kind(), ErrorKind::UniqueViolation);
+
+    Ok(())
+}
+
+#[sqlx_macros::test]
+async fn it_fails_with_foreign_key_violation() -> anyhow::Result<()> {
+    let mut conn = new::<Sqlite>().await?;
+    let mut tx = conn.begin().await?;
+
+    let res: Result<_, sqlx::Error> =
+        sqlx::query("INSERT INTO tweet_reply (id, tweet_id, text) VALUES (2, 2, 'Reply!');")
+            .execute(&mut *tx)
+            .await;
+    let err = res.unwrap_err();
+
+    let err = err.into_database_error().unwrap();
+
+    assert_eq!(err.kind(), ErrorKind::ForeignKeyViolation);
+
+    Ok(())
+}
+
+#[sqlx_macros::test]
+async fn it_fails_with_not_null_violation() -> anyhow::Result<()> {
+    let mut conn = new::<Sqlite>().await?;
+    let mut tx = conn.begin().await?;
+
+    let res: Result<_, sqlx::Error> = sqlx::query("INSERT INTO tweet (text) VALUES (null);")
+        .execute(&mut *tx)
+        .await;
+    let err = res.unwrap_err();
+
+    let err = err.into_database_error().unwrap();
+
+    assert_eq!(err.kind(), ErrorKind::NotNullViolation);
+
+    Ok(())
+}
+
+#[sqlx_macros::test]
+async fn it_fails_with_check_violation() -> anyhow::Result<()> {
+    let mut conn = new::<Sqlite>().await?;
+    let mut tx = conn.begin().await?;
+
+    let res: Result<_, sqlx::Error> =
+        sqlx::query("INSERT INTO products VALUES (1, 'Product 1', 0);")
+            .execute(&mut *tx)
+            .await;
+    let err = res.unwrap_err();
+
+    let err = err.into_database_error().unwrap();
+
+    assert_eq!(err.kind(), ErrorKind::CheckViolation);
+
+    Ok(())
+}

tests/sqlite/setup.sql

@@ -8,6 +8,16 @@ CREATE TABLE tweet (
 INSERT INTO tweet(id, text, owner_id)
 VALUES (1, '#sqlx is pretty cool!', 1);
 --
+CREATE TABLE tweet_reply (
+    id BIGINT NOT NULL PRIMARY KEY,
+    tweet_id BIGINT NOT NULL,
+    text TEXT NOT NULL,
+    owner_id BIGINT,
+    CONSTRAINT tweet_id_fk FOREIGN KEY (tweet_id) REFERENCES tweet(id)
+);
+INSERT INTO tweet_reply(id, tweet_id, text, owner_id)
+VALUES (1, 1, 'Yeah! #sqlx is indeed pretty cool!', 1);
+--
 CREATE TABLE accounts (
     id INTEGER NOT NULL PRIMARY KEY,
     name TEXT NOT NULL,
@@ -18,3 +28,10 @@ VALUES (1, 'Herp Derpinson', 1);
 CREATE VIEW accounts_view as
 SELECT *
 FROM accounts;
+--
+CREATE TABLE products (
+    product_no INTEGER,
+    name TEXT,
+    price NUMERIC,
+    CONSTRAINT price_greater_than_zero CHECK (price > 0)
+);