在MongoDB集合中向数组添加单个值的脚本？
若要仅将单个值添加到数组，请使用$push。首先让我们创建一个包含文档的集合-
> db.demo3.insertOne(
... {
... "Information" : {
... "Of" : {
... "StudentCode" : "STUDENT101",
... "StudentFavouriteSubject" : [
... "MySQL",
... "Java"
... ]
... }
... }
... }
... );
{
"acknowledged" : true,
"insertedId" : ObjectId("5e08b7ef25ddae1f53b6221b")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.demo3.find();
这将产生以下输出-
{ "_id" : ObjectId("5e08b7ef25ddae1f53b6221b"), "Information" : { "Of" : { "StudentCode" : "STUDENT101", "StudentFavouriteSubject" : [ "MySQL", "Java" ] } } }这是仅向MongoDB中的数组添加单个值的查询-
> db.demo3.update({},{$push:{"Information.Of.StudentFavouriteSubject":"Spring and Hibernate"}});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })让我们再次检查所有文件-
> db.demo3.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5e08b7ef25ddae1f53b6221b"),
"Information" : {
"Of" : {
"StudentCode" : "STUDENT101",
"StudentFavouriteSubject" : [
"MySQL",
"Java",
"Spring and Hibernate"
]
}
}
}