Add DatabaseError::code

sqlx-core/src/error.rs

@@ -177,6 +177,11 @@ pub trait DatabaseError: Display + Debug + Send + Sync {
     /// The primary, human-readable error message.
     fn message(&self) -> &str;
 
+    /// The (SQLSTATE) code for the error.
+    fn code(&self) -> Option<&str> {
+        None
+    }
+
     fn details(&self) -> Option<&str> {
         None
     }

sqlx-core/src/mysql/error.rs

@@ -16,4 +16,8 @@ impl DatabaseError for MySqlError {
     fn message(&self) -> &str {
         &*self.0.error_message
     }
+
+    fn code(&self) -> Option<&str> {
+        self.0.sql_state.as_deref()
+    }
 }

sqlx-core/src/postgres/error.rs

@@ -11,6 +11,10 @@ impl DatabaseError for PgError {
         &self.0.message
     }
 
+    fn code(&self) -> Option<&str> {
+        Some(&self.0.code)
+    }
+
     fn details(&self) -> Option<&str> {
         self.0.detail.as_ref().map(|s| &**s)
     }

sqlx-core/src/sqlite/error.rs

@@ -7,8 +7,7 @@ use std::os::raw::c_int;
 
 #[derive(Debug)]
 pub struct SqliteError {
-    #[allow(dead_code)]
-    code: c_int,
+    code: String,
     message: String,
 }
 
@@ -29,7 +28,7 @@ impl SqliteError {
         };
 
         Self {
-            code,
+            code: code.to_string(),
             message: message.to_owned(),
         }
     }
@@ -45,4 +44,8 @@ impl DatabaseError for SqliteError {
     fn message(&self) -> &str {
         &self.message
     }
+
+    fn code(&self) -> Option<&str> {
+        &self.code
+    }
 }