Fix bugs, improve schema gen

README.md

@@ -307,15 +307,41 @@ type BUN_MARIADB_FieldSchemaType = {
 ### Foreign Key
 
 ```ts
+type BUN_MARIADB_ForeignKeyRule =
+    | "CASCADE"
+    | "SET NULL"
+    | "RESTRICT"
+    | "NO ACTION";
+
 interface BUN_MARIADB_ForeignKeyType {
     foreignKeyName?: string;
     destinationTableName?: string;
     destinationTableColumnName?: string;
-    cascadeDelete?: boolean;
-    cascadeUpdate?: boolean;
+    cascadeDelete?: boolean; // shorthand for onDelete: "CASCADE"
+    cascadeUpdate?: boolean; // shorthand for onUpdate: "CASCADE"
+    onDelete?: BUN_MARIADB_ForeignKeyRule; // default RESTRICT
+    onUpdate?: BUN_MARIADB_ForeignKeyRule; // default RESTRICT
 }
 ```
 
+```ts
+{
+    fieldName: "author_id",
+    dataType: "BIGINT",
+    foreignKey: {
+        foreignKeyName: "post_author_fk",
+        destinationTableName: "users",
+        destinationTableColumnName: "id",
+        onDelete: "SET NULL", // column must be nullable
+    },
+}
+```
+
+- `onDelete` / `onUpdate` take precedence over the `cascadeDelete` / `cascadeUpdate` shorthands. The deprecated field-level `onDeleteLiteral` / `onDelete` are still honored as the FK's ON DELETE action when `foreignKey.onDelete` is not set.
+- `SET NULL` on a `notNullValue` or primary key column is rejected when the schema syncs.
+- Changing a rule on an existing FK drops and recreates the constraint. `NO ACTION` and `RESTRICT` are treated as the same rule, so switching between them causes no churn.
+- Foreign keys are created after every table exists. Self references (e.g. `comments.parent_comment_id`), forward references and cycles between tables are all supported.
+
 ### Index
 
 ```ts