feat(System Variables): There is only one option when selecting a variable; you do not need to select it again.

Author: dataeaseShu

frontend/src/views/system/user/User.vue

@@ -386,6 +386,7 @@
             <el-select
               v-model="state.form.system_variables[index].variableId"
               style="width: 236px"
+              @change="handleVariableChange(index)"
               :placeholder="$t('datasource.Please_select')"
             >
               <el-option
@@ -686,6 +687,14 @@ const getVariableOptionList = (variableId: string) => {
   return []
 }
 
+const handleVariableChange = (index: number) => {
+  state.form.system_variables[index].variableValues = []
+  const variable = variableValueMap.value[state.form.system_variables[index].variableId]
+  if (variable && variable.value.length === 1) {
+    state.form.system_variables[index].variableValues = [variable.value[0]]
+  }
+}
+
 const getSelectedKeysFromStoredValues = (variableId: string, storedValues: any[] = []) => {
   const variable = getVariableDefinition(variableId)
   if (!variable || variable.var_type !== 'kv') return storedValues