db.dbtestregex.find({data:{ $regex:/<Head>OK<\/Head>/}})
{
"_id" : ObjectId("5d305bb74857fc49c0c14c87"),
"order" : "QQ00003",
"data" : "\"<?xml version='1.0' encoding='UTF-8'?><Response service=\\\"OrderService\\\"><Head>OK</Head><Body><OrderResponse filter_mmm=\\\"2\\\" destcity=\\\"shenzheng\\\" origincode=\\\"QQ0003\\\" /></Body></Response>\""
},
{
"_id" : ObjectId("5d305bd14857fc49c0c14c88"),
"order" : "QQ00002",
"data" : "\"<?xml version='1.0' encoding='UTF-8'?><Response service=\\\"OrderService\\\"><Head>OK</Head><Body><OrderResponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"QQ0002\\\" /></Body></Response>\""
},
{
"_id" : ObjectId("5d305be94857fc49c0c14c89"),
"order" : "QQ00001",
"data" : "\"<?xml version='1.0' encoding='UTF-8'?><Response service=\\\"OrderService\\\"><Head>OK</Head><Body><OrderResponse filter_mmm=\\\"2\\\" destcity=\\\"zhongshan\\\" origincode=\\\"QQ0001\\\" /></Body></Response>\""
}
db.dbtestregex.find({data:/<Head>OK<\/Head>/})
{
"_id" : ObjectId("5d305bb74857fc49c0c14c87"),
"order" : "QQ00003",
"data" : "\"<?xml version='1.0' encoding='UTF-8'?><Response service=\\\"OrderService\\\"><Head>OK</Head><Body><OrderResponse filter_mmm=\\\"2\\\" destcity=\\\"shenzheng\\\" origincode=\\\"QQ0003\\\" /></Body></Response>\""
},
{
"_id" : ObjectId("5d305bd14857fc49c0c14c88"),
"order" : "QQ00002",
"data" : "\"<?xml version='1.0' encoding='UTF-8'?><Response s