Knex adapter internal updates

.changeset/fast-windows-kneel.md

@@ -0,0 +1,5 @@
+---
+'@keystonejs/adapter-knex': patch
+---
+
+Refactored internals to prepare for future changes.

packages/adapter-knex/lib/adapter-knex.js

@@ -286,6 +286,8 @@ class KnexListAdapter extends BaseListAdapter {
     });
   }
 
+  ////////// Mutations //////////
+
   async _processNonRealFields(data, processFunction) {
     return resolveAllKeys(
       arrayToObject(
@@ -300,7 +302,22 @@ class KnexListAdapter extends BaseListAdapter {
     );
   }
 
-  ////////// Mutations //////////
+  async _createSingle(realData) {
+    const item = (
+      await this._query()
+        .insert(realData)
+        .into(this.tableName)
+        .returning('*')
+    )[0];
+    return { item, itemId: item.id };
+  }
+
+  async _setNullByValue({ tableName, columnName, value }) {
+    return this._query()
+      .table(tableName)
+      .where(columnName, value)
+      .update({ [columnName]: null });
+  }
 
   async _createOrUpdateField({ value, adapter, itemId }) {
     const rel = {
@@ -334,23 +351,19 @@ class KnexListAdapter extends BaseListAdapter {
     const realData = pick(data, this.realKeys);
 
     // Insert the real data into the table
-    const item = (
-      await this._query()
-        .insert(realData)
-        .into(this.tableName)
-        .returning('*')
-    )[0];
+    const { item, itemId } = await this._createSingle(realData);
 
     // For every many-field, update the many-table
     const manyItem = await this._processNonRealFields(data, async ({ value, adapter }) =>
-      this._createOrUpdateField({ value, adapter, itemId: item.id })
+      this._createOrUpdateField({ value, adapter, itemId })
     );
 
     return { ...item, ...manyItem };
   }
 
   async _update(id, data) {
     const realData = pick(data, this.realKeys);
+
     // Update the real data
     const query = this._query()
       .table(this.tableName)
@@ -428,15 +441,13 @@ class KnexListAdapter extends BaseListAdapter {
                   .where(columnNames[this.key].near, id)
                   .del();
               } else {
-                return this._query()
-                  .table(tableName)
-                  .where(columnName, id)
-                  .update({ [columnName]: null });
+                return this._setNullByValue({ tableName, columnName, value: id });
               }
             })
         )
       )
     );
+
     // Delete the actual item
     return this._query()
       .table(this.tableName)