fix(table): reset select filter value

src/components/table/mixins/table.js

@@ -91,7 +91,7 @@ export default {
 
     const filterMap = {}
     this.filters = this.schema.filters?.map(filter => {
-      filterMap[filter.key] = filter.type
+      filterMap[filter.key] = filter
       return {
         ...filter,
         loading: false,
@@ -192,10 +192,11 @@ export default {
         const paramValue = params[key]
         if (paramValue != null && paramValue !== '') {
           const value = condition[key]
-          switch (this.filterMap[key]) {
+          const filter = this.filterMap[key]
+          switch (filter.key) {
             case 'select':
               if (paramValue !== value) {
-                params[key] = void 0
+                params[key] = filter.placeholder ? void 0 : value
               }
               break
             case 'search':