commandExists('ls') .then(function(command){ //proceed }).catch(function(){ //command doesn't exist }); sync varcommandExistsSync=require('command-exists').sync; //returns true/false; doesn't throw if(commandExistsSync('ls')){
varcommandExists =require('command-exists');// invoked without a callback, it returns a promisecommandExists('ls') .then(function(command){// proceed}).catch(function(){// command doesn't exist}); sync varcommandExistsSync =require('command-exists').sync;// returns true/false; doesn't ...
针对您提出的 redis.exceptions.ResponseError: unknown command 'exists' 错误,以下是一些可能的解决步骤和建议,旨在帮助您诊断和解决问题: 确认exists命令的存在: EXISTS 命令是 Redis 的一个标准命令,用于检查给定键是否存在。在大多数 Redis 版本中,这个命令都是可用的。因此,您首先需要确认您的 Redis 版本是否支...
Command.exists(value: boolean): Command 支持端:小程序 2.8.3, 云函数 1.2.1, Web 判断字段是否存在 参数 value: boolean 返回值 Command 示例代码 找出存在 tags 字段的记录 const _ = db.command db.collection('todos').where({ tags: _.exists(true) }) .get({ success: console.lo...
res := &batchCommandExists{ batchCommand: batchCommand{ client: client, baseMultiCommand: *newMultiCommand(node, nil, false), policy: policy, batch: batch, }, keys: keys, existsArray: existsArray, } return res } func (cmd *batchCommandExists) cloneBatchCommand(batch *batchNode) batcher {...
Redis server response timeout (3000 ms) occured after 3 retry attempts. Command: (EXISTS), params: [XXXX], channel: [id: 0xXXXX, L:/XXXXX.45.128:44772 - R:10.122.67.XX/10.122.67.56:6379]X rg.redisson.client.RedisResponseTimeoutException: Redis server response timeout (3000 ms) occured...
Caused by: redis.clients.jedis.exceptions.JedisDataException: ERR unknown command 'EXISTS' ERR unknown command 'EXISTS' 原因是本地redis地址配错了。 配成下图这样就好了。
This command returns 0 if none of these can be found. Return valueint 0 or 1MEL examplesif (`exists sphere`) { sphere; // make a sphere } string $myCommand="cone"; if (`exists $myCommand`) { eval $myCommand; }
Unfortunately I have encountered another problem. I have installed python 2.7.5 with pyenv install 2.7.5 and then pyenv rehash Now if I type python2.7 I get pyenv: python2.7: command not found The `python2.7' command exists in these Pyth...
第3章_关系数据库标准语言(SQL)_006_由元组关系演算到SQL Command_001_蕴含式 (其中有对EXISTS的分析) 前序的链接:元组关系演算 六. 蕴含式 ===》 1. 什么是“蕴含式”===》 设p、q为两个命题。复合命题“如果p,则q”称为p与q的蕴含式,记作p→q,并称p为蕴含式的前件,q为后件。定义中规定p→...