async与await的用法
function test(){
return new Promise((resolve, reject) => {
mysql.query(sql, (error, result, fields) => {
if (error) {
reject(error);
} else {
resolve([result, fields]);
}
})
});
}
async function exceTest() {
return await test();
}
var data = await exceTest();
async的使用条件:必须是promise对象