support remove fields for mongo

plugins/dbgate-plugin-mongo/src/frontend/driver.js

@@ -2,6 +2,8 @@ const { driverBase } = global.DBGATE_PACKAGES['dbgate-tools'];
 const { convertToMongoCondition, convertToMongoSort } = require('./convertToMongoCondition');
 const Dumper = require('./Dumper');
 const { mongoSplitterOptions } = require('dbgate-query-splitter/lib/options');
+const _pickBy = require('lodash/pickBy');
+const _fromPairs = require('lodash/fromPairs');
 
 function jsonStringifyWithObjectId(obj) {
   return JSON.stringify(obj, undefined, 2).replace(
@@ -96,7 +98,12 @@ const driver = {
         res += `db.${update.pureName}.updateOne(${jsonStringifyWithObjectId(
           update.condition
         )}, ${jsonStringifyWithObjectId({
-          $set: update.fields,
+          $set: _pickBy(update.fields, (v, k) => v !== undefined),
+          $unset: _fromPairs(
+            Object.keys(update.fields)
+              .filter((k) => update.fields[k] === undefined)
+              .map((k) => [k, ''])
+          ),
         })});\n`;
       }
     }
@@ -140,6 +147,8 @@ const driver = {
     supportJsonType: true,
     supportObjectIdType: true,
     supportNullType: true,
+
+    supportFieldRemoval: true,
   },
 };