总结一下mysql语句在node.js中的各种写法,参考了npm网站mysql模块给的实例。
查询 select
//1 db.query('select * from tuanshang_users where user_id < 10',function(err,results,fields){//if(err) throw err;console.log( results );if(!!results.length){console.log('查询到'+ results.length +'条数据');}else{console.log('没有相关数据');} }); //2 db.query('select * from tuanshang_users where user_id=?',[8],function(err,results,fields){if(err) throw err;console.log( results ); }); //3 db.query({sql: 'select * from tuanshang_users where user_id=? and username=?',values: [43,'ABCD'],timeout: 40000 },function(err,results,fields){if(err) throw err;console.log( results ); }); //4 db.query({sql: 'select * from tuanshang_users where user_id=? and username=?',timeout: 40000 },[44,'ABCDEF'],function(err,results,fields){if(err) throw err;console.log( results ); }); //5 var userid = 44; var columns = ['username','password']; var sql = 'select ?? from ?? where user_id=?'; db.query(sql,[columns,'tuanshang_users',userid],function(err,results,fields){if(err) throw err;console.log( results ); });
插入 insert into
//1 var o = {username:'cnode', password:'123456'}; db.query('insert into tuanshang_users set ?', o, function(err,result){console.log( result );if(result){console.log('插入成功');console.log( result.insertId );}else{console.log('插入失败');} }); //2 db.query('insert into tuanshang_users set ?',{username:'hello',password:'123456'}, function(err,result){//if(err) throw err;if(result){console.log('插入成功');console.log( result );}else{console.log('插入失败');} }); //3 db.query({sql: 'insert into tuanshang_users set ?',values: {username:'kankan',password:'123456'},timeout: 40000 },function(err,result){//if(err) throw err;console.log( result ); if( !!result ){console.log('插入成功');console.log( result.insertId );}else{console.log('插入失败');} }); //4 5 参考查询select
更新 update
//1 db.query('update tuanshang_users set ? where user_id=?',[{username:'hello'},8],function(err,result){//if(err) throw err;console.log(result);if(!!result && !!result.changedRows){console.log('更新成功');console.log( result.changedRows ); }else{console.log('更新失败');} }); //2 db.query('update tuanshang_users set ? where user_id=5',{username:'hello'},function(err,result){//if(err) throw err;console.log(result);if(!!result && !!result.changedRows){console.log('更新成功');console.log( result.changedRows ); }else{console.log('更新失败');} }); //3 db.query({sql: 'update tuanshang_users set ? where user_id=?',values: [{username:'hello'},8],timeout: 40000 },function(err,result){//if(err) throw err;console.log( result ); if(!!result && !!result.changedRows){console.log('更新成功');console.log( result.changedRows ); }else{console.log('更新失败');} }); //4 5 参考查询select
删除 delete
//1 db.query('delete from tuanshang_users where username="hello"',function(err,result){//if(err) throw err;console.log( result ); if(!!result && !!result.affectedRows){console.log('删除成功');console.log( result.affectedRows ); }else{console.log('删除失败');} }); //2 db.query('delete from tuanshang_users where user_id=?',[10],function(err,result){//if(err) throw err;console.log( result ); if(!!result && !!result.affectedRows){console.log('删除成功');console.log( result.affectedRows ); }else{console.log('删除失败');} }); //3 db.query({sql: 'delete from tuanshang_users where user_id=?',values: [51],timeout: 40000 },function(err,result){//if(err) throw err;console.log( result ); if(!!result && !!result.affectedRows){console.log('删除成功');console.log( result.affectedRows ); }else{console.log('删除失败');} }); //4 5 参考查询select
查询操作,会返回一个结果数组。如果没有查询数据,结果数组为空,即数组长度为0。
插入,更新,删除操作会返回一个结果对象
{ fieldCount: 0,affectedRows: 0,insertId: 0,serverStatus: 2,warningCount: 0,message: '',protocol41: true,changedRows: 0 }
在插入操作后,结果对象中 insertId 返回插入的数据在表中id的位置。
在更新操作后,结果对象中 changedRows 返回更新了多少行(表中有几条数据中的字段值发生变化),affectedRows 返回满足where条件影响的行。
在删除操作后,结果对象中 affectedRows 返回删除了多少行。如果是0表示没有删除行或者没有满足删除条件的数据行。