Write a Valid MySQL Query and Update with a Custom Variable

AmitDiwan
Updated on 06-Apr-2020 13:35:56

398 Views

Let us first create a table −mysql> create table DemoTable2027    -> (    -> UserId int    -> ); Query OK, 0 rows affected (0.65 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2027 values(10); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable2027 values(20); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable2027 values(31); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable2027 values(11); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select *from DemoTable2027;This will produce ... Read More

Add Minutes to Varchar Datetime Records in MySQL

AmitDiwan
Updated on 06-Apr-2020 13:33:31

188 Views

Yes, we can add minutes while inserting values in a table.Let us first create a table. Here, we have a column with VARCHAR records where inmysql> create table DemoTable2026    -> (    -> ArrivalTime varchar(20)    -> ); Query OK, 0 rows affected (0.40 sec)Insert some records in the table using insert command. We are first converting the VARCHAR date and then adding minutes −mysql> insert into DemoTable2026 values(date_add(str_to_date('2017-12-01 11:34:45', '%Y-%m-%d %H:%i:%s'), INTERVAL 10 MINUTE)); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable2026 values(date_add(str_to_date('2015-01-31 10:00:00', '%Y-%m-%d %H:%i:%s'), INTERVAL 5 MINUTE)); Query OK, 1 row affected ... Read More

Improve MongoDB Queries with Multikey Index in Array

AmitDiwan
Updated on 06-Apr-2020 13:32:46

181 Views

For this, use $elemMatch, which is used to query nested objects. Let us create a collection with documents −> db.demo444.insertOne( ...    { ...       "Information": [{ ...          id:1, ...          Name:"Chris" ...       }] ...    } ... ); {    "acknowledged" : true,    "insertedId" : ObjectId("5e78ea87bbc41e36cc3caebf") } > db.demo444.insertOne( ...    { ...       "Information": [{ ...          id:2, ...          Name:"David" ...       }] ...    } ... ); {    "acknowledged" : true,   ... Read More

Find and Replace a Part of URL Records in MySQL

AmitDiwan
Updated on 06-Apr-2020 13:31:49

956 Views

The simplest way to replace records is using MySQL REPLACE() −mysql> create table DemoTable2025    -> (    -> URL text    -> ); Query OK, 0 rows affected (0.88 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2025 values('http=//www.facebook.com'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable2025 values('http=//www.google.com'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable2025 values('http=//www.gmail.com'); Query OK, 1 row affected (0.26 sec)Display all records from the table using select statement −mysql> select *from DemoTable2025;This will produce the following output −+-------------------------+ | URL ... Read More

MongoDB Profiler Output: Command Operation Explained

AmitDiwan
Updated on 06-Apr-2020 13:30:22

254 Views

The following operations are treated as command operation in MongoDB −1.count 2.findAndModify 3.aggregateFollowing is the example of count in MongoDB −Let us create a collection with documents −> db.demo443.insertOne({"Name":"Chris"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e78d281bbc41e36cc3caeb9") } > db.demo443.insertOne({"Name":"Bob"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e78d285bbc41e36cc3caeba") } > db.demo443.insertOne({"Name":"David"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e78d288bbc41e36cc3caebb") }Display all documents from a collection with the help of find() method −> db.demo443.find();This will produce the following output −{ "_id" : ObjectId("5e78d281bbc41e36cc3caeb9"), "Name" : "Chris" } { "_id" : ObjectId("5e78d285bbc41e36cc3caeba"), "Name" : "Bob" } { "_id" : ... Read More

Return a List from Different Rows into a Single Field with MySQL

AmitDiwan
Updated on 06-Apr-2020 13:29:37

894 Views

For this, use GROUP_CONCAT(). Let us first create a table −mysql> create table DemoTable2024    -> (    -> SubjectName varchar(20),    -> StudentName varchar(20)    -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2024 values('MySQL', 'Chris'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable2024 values('MySQL', 'David'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable2024 values('MongoDB', 'Bob'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable2024 values('Java', 'Sam'); Query OK, 1 row affected (0.18 sec) mysql> ... Read More

Getting Distinct Values from Object Array in MongoDB

AmitDiwan
Updated on 06-Apr-2020 13:28:05

1K+ Views

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

MySQL Regular Expression to Update Table with Column Values

AmitDiwan
Updated on 06-Apr-2020 13:26:18

760 Views

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

MongoDB Query to Aggregate Nested Array

AmitDiwan
Updated on 06-Apr-2020 13:25:14

1K+ Views

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

Insert Multiple Values in a Column with a Single MySQL Query

AmitDiwan
Updated on 06-Apr-2020 13:24:43

2K+ Views

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

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