var util=require(‘util‘);var mysql=require(‘mysql‘);const HOST=‘127.0.0.1‘;const USER=‘root‘;const PASS=‘‘;const prefix=‘blog_‘;const DATABASE=‘app_blog‘;const PORT=3306const db=mysql.createPool({    host:HOST,    user:USER,    password:PASS,    database:DATABASE,    port:PORT});var findOne=function (table,where,callback){ //查找一条；    // whre is arr; [{id:1},{username:admin}];    var _WHERE=‘‘;    if(util.isObject(where)){        _WHERE+=‘WHERE ‘;        for(var k in where){            _WHERE+=k+"=‘"+where[k]+"‘ AND ";        }              _WHERE=_WHERE.slice(0,-4);    }else if(typeof where ==‘string‘){        _WHERE=‘WHERE ‘+where;    }   var sql="SELECT * FROM "+prefix+table+‘ ‘+_WHERE+‘ LIMIT 1‘;   console.log(sql+‘-------------------------‘);   db.query(sql,function(err,data){        if(err){            callback(err,0);        }else{            callback(err,data[0]);        }   });}var select=function(table,callback){ //查找所有；    var sql="SELECT * FROM "+prefix+table;    console.log(sql);    db.query(sql,callback);}var insert =function(table,obj,callback){    //insert into table() values()    //{username:‘guojikai‘,age:‘55‘,sex:‘1‘}    var fields=‘‘;    var values=‘‘;    for( var k in obj){        fields+=k+‘,‘;        values=values+"‘"+obj[k]+"‘,"    }    fields=fields.slice(0,-1);    values=values.slice(0,-1);    var sql="INSERT INTO "+prefix+table+‘(‘+fields+‘) VALUES(‘+values+‘)‘;    console.log(sql+‘--------------‘);    db.query(sql,callback);}/**  sets is object；  where is object;*/var update=function(table,sets,where,callback){    var _SETS=‘‘;    var _WHERE=‘‘;    var keys=‘‘;    var values=‘‘;    for(var k in sets){        _SETS+=k+"=‘"+sets[k]+"‘,";    }    _SETS=_SETS.slice(0,-1);    for(var k2 in where){        _WHERE+=k+"=‘"+where[k2]+"‘ AND ";    }    //update table set username=‘admin2‘,age=‘55‘   where id="5";    var sql="UPDATE "+prefix+table+‘ SET ‘+_SETS+‘ ‘+_WHERE;    db.query(sql,callback);}var del=function(table,where,callback){    var _WHERE=‘‘;    for(var k2 in where){        _WHERE+=k+"=‘"+where[k2]+"‘ AND ";    }     var sql="DELETE  FROM "+prefix+table+‘  ‘+_WHERE;}// var sql_select="SELECT * FROM blog_article";module.exports={    db:db,    insert:insert,    select:select,    find:find,    del:del,    update:update};

var util=require(‘util‘);var mysql=require(‘mysql‘);const HOST=‘127.0.0.1‘;const USER=‘root‘;const PASS=‘‘;const prefix=‘blog_‘;const DATABASE=‘app_blog‘;const PORT=3306const db=mysql.createPool({    host:HOST,    user:USER,    password:PASS,    database:DATABASE,    port:PORT});var findOne=function (table,where,callback){ //查找一条；    // whre is arr; [{id:1},{username:admin}];    var _WHERE=‘‘;    if(util.isObject(where)){        _WHERE+=‘WHERE ‘;        for(var k in where){            _WHERE+=k+"=‘"+where[k]+"‘ AND ";        }              _WHERE=_WHERE.slice(0,-4);    }else if(typeof where ==‘string‘){        _WHERE=‘WHERE ‘+where;    }   var sql="SELECT * FROM "+prefix+table+‘ ‘+_WHERE+‘ LIMIT 1‘;   console.log(sql+‘-------------------------‘);   db.query(sql,function(err,data){        if(err){            callback(err,0);        }else{            callback(err,data[0]);        }   });}var select=function(table,callback){ //查找所有；    var sql="SELECT * FROM "+prefix+table;    console.log(sql);    db.query(sql,callback);}var insert =function(table,obj,callback){    //insert into table() values()    //{username:‘guojikai‘,age:‘55‘,sex:‘1‘}    var fields=‘‘;    var values=‘‘;    for( var k in obj){        fields+=k+‘,‘;        values=values+"‘"+obj[k]+"‘,"    }    fields=fields.slice(0,-1);    values=values.slice(0,-1);    var sql="INSERT INTO "+prefix+table+‘(‘+fields+‘) VALUES(‘+values+‘)‘;    console.log(sql+‘--------------‘);    db.query(sql,callback);}/**  sets is object；  where is object;*/var update=function(table,sets,where,callback){    var _SETS=‘‘;    var _WHERE=‘‘;    var keys=‘‘;    var values=‘‘;    for(var k in sets){        _SETS+=k+"=‘"+sets[k]+"‘,";    }    _SETS=_SETS.slice(0,-1);    for(var k2 in where){        _WHERE+=k+"=‘"+where[k2]+"‘ AND ";    }    //update table set username=‘admin2‘,age=‘55‘   where id="5";    var sql="UPDATE "+prefix+table+‘ SET ‘+_SETS+‘ ‘+_WHERE;    db.query(sql,callback);}var del=function(table,where,callback){    var _WHERE=‘‘;    for(var k2 in where){        _WHERE+=k+"=‘"+where[k2]+"‘ AND ";    }     var sql="DELETE  FROM "+prefix+table+‘  ‘+_WHERE;}// var sql_select="SELECT * FROM blog_article";module.exports={    db:db,    insert:insert,    select:select,    find:find,    del:del,    update:update};

node-mysql增删改查封装