To get distinct values from object array in MongoDB, use distinct(). Let us create a collection with documents −> db.demo442.insertOne( ...    { ... ...       "Information" : [ ...          { ...             "FirstName" : "John", ...             "Age" : 21 ...          }, ...          { ...             "FirstName" : "Sam", ...             "Age" : 23 ...          }, ...         ... Read More

For this, use UPDATE command along with REGEXP. Let us first create a table −mysql> create table DemoTable2023    -> (    -> StreetNumber varchar(100)    -> ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2023 values('7'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable2023 values('1'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable2023 values('AUS-100'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable2023 values('US-101'); Query OK, 1 row affected (0.11 sec)Display all records from the table using ... Read More

To insert multiple values in a column, the syntax is as follows −insert into yourTableName values(yourValue1), (yourValue2), ..........N;To understand the above syntax, let us create a table −mysql> create table DemoTable2022    -> (    -> Department varchar(100)    -> ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2022 values('Computer Science'), ('Information Technology'), ('Civil'), ('Mechanical'), ('Electronics'), ('Electrical'); Query OK, 6 rows affected (0.46 sec) Records: 6 Duplicates: 0 Warnings: 0Display all records from the table using select statement −mysql> select *from DemoTable2022;This will produce the following ... Read More

To insert data from one scheme to another, the syntax is as follows. Here, we have two databases “yourDatabaseName1” and “yourDatabaseName2” −insert into yourDatabaseName2.yourTableName2 select *from yourDatabaseName1.yourTableName1;To understand the above syntax, let us create a table. We are creating a table in database “web” −mysql> create table DemoTable2020    -> (    -> Id int,    -> Name varchar(20)    -> ); Query OK, 0 rows affected (0.67 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2020 values(101, 'Chris'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable2020 values(102, 'David'); Query OK, 1 ... Read More

To aggregate nested array in MongoDB, use aggregate(). Let us create a collection with documents −> db.demo441.insertOne( ...    { ... ...       "Name" : "David", ...       "Age" : 21, ... ...       "details" : [ ...          { ...             "id" : 1, ...             "CountryName" : "US", ...             "details1" : [ ...                { ...                   "SubjectName" : ... Read More

To count items in array, use length. Let us create a collection with documents −> db.demo440.insertOne( ...    { ...       "Name":"Chris", ...       "ListOfFriends":["John", "Sam", "Mike"] ...    } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e78c63cbbc41e36cc3caeb5") } > > db.demo440.insertOne( ...    { ...       "Name":"David", ...       "ListOfFriends":["Mike", "Bob", "Carol"] ...    } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e78c63cbbc41e36cc3caeb6") }Display all documents from a collection with the help of find() method −> db.demo440.find();This will produce the following output −{ "_id" : ... Read More

To project field in MongoDB, use $project. Let us create a collection with documents −> db.demo439.insertOne( ...    { ...       "Name" : "Chris", ...       "MarksInformation" : { ...          "Marks1" : 67, ...          "Marks2" :45, ...          "Marks3" : 78 ...       } ...    } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e77833abbc41e36cc3caeab") } > db.demo439.insertOne( ...    { ...       "Name" : "David", ...       "MarksInformation" : { ...         ... Read More

To update field with GROUP BY, use ORDER BY LIMIT with UPDATE command −mysql> create table DemoTable2018    -> (    -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> EmployeeName varchar(20),    -> EmployeeSalary int    -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2018(EmployeeName, EmployeeSalary) values('Chris', 10000); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable2018(EmployeeName, EmployeeSalary) values('David', 12560); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable2018(EmployeeName, EmployeeSalary) values('Chris', 25400); Query OK, 1 row affected (0.09 sec)Display all ... Read More

Let us first create a table −mysql> create table DemoTable2017    -> (    -> Name text    -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2017 values('JOHN SMITH, MYSQL'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable2017 values('DAVID MILLER, MONGODB'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable2017 values('CHRIS BROWN, JAVA'); Query OK, 1 row affected (0.11 sec)Display all records from the table using select statement −mysql> select *from DemoTable2017;This will produce the following output −+----------------------+ | Name   ... Read More

To remove duplicate record, use aggregate(). Let us create a collection with documents −> db.demo438.insertOne({"FirstName":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e775c37bbc41e36cc3caea1") } > db.demo438.insertOne({"FirstName":"David"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e775c3dbbc41e36cc3caea2") } > db.demo438.insertOne({"FirstName":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e775c40bbc41e36cc3caea3") } > db.demo438.insertOne({"FirstName":"Bob"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e775c44bbc41e36cc3caea4") } > db.demo438.insertOne({"FirstName":"David"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e775c47bbc41e36cc3caea5") }Display all documents from a collection with the help of find() method −> db.demo438.find();This will produce the following output −{ "_id" : ObjectId("5e775c37bbc41e36cc3caea1"), "FirstName" : "Chris" } { ... Read More