To delete all rows except a single specific row, try the below syntax −delete from yourTableName where yourColumnName!=yourValue;Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Subject varchar(100)    ); Query OK, 0 rows affected (0.65 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Subject) values('MySQL'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(Subject) values('Java'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select ... Read More

You can use CONCAT() for this. The syntax is as follows −insert into DemoTable values(concat(curdate(), ' yourSpecificTime’));Let us first create a table −mysql> create table DemoTable    (    ArrivalDate datetime    ); Query OK, 0 rows affected (1.06 sec)Insert some records in the table using insert command. We are adding the current date and time −mysql> insert into DemoTable values(concat(curdate(), ' 10:20:05')); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(concat(curdate(), ' 12:05:00')); Query OK, 1 row affected (0.17 sec)Display all records from the table using select statement −mysql> select *from DemoTable;Output+---------------------+ | ArrivalDate ... Read More

You can use delete command −delete from yourTableName where yourColumnName='\\';Let us first create a table −mysql> create table DemoTable    (    FolderName varchar(100)    ); Query OK, 0 rows affected (0.67 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values("????"); Query OK, 1 row affected (0.44 sec) mysql> insert into DemoTable values("\\"); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select *from DemoTable;Output+------------+ | FolderName | +------------+ | ???? | | \ ... Read More

For this, use the CONCAT() function. Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Subject varchar(200)    ); Query OK, 0 rows affected (1.36 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Subject) values('MySQL'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Subject) values('MongoDB'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(Subject) values('Java'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select *from DemoTable;Output+----+---------+ | Id | Subject | +----+---------+ ... Read More

Use the str_to_date() method −select month(str_to_date(yourColumnName, '%b')) from yourTableName;Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    MonthName varchar(100)    ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(MonthName) values('Jan'); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable(MonthName) values('Mar'); Query OK, 1 row affected (0.13 sec) Display all records from the table using select statement: mysql> select *from DemoTable;Output+----+-----------+ | Id | MonthName | +----+-----------+ | 1 | Jan ... Read More

You can use str_to_date() for this conversion. Let us first create a table −mysql> create table DemoTable    (    stringDate varchar(100)    ); Query OK, 0 rows affected (0.86 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('1h 15 min'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values('2h 30 min'); Query OK, 1 row affected (0.21 sec)Display all records from the table using select statement −mysql> select *from DemoTable;Output+------------+ | stringDate | +------------+ | 1h 15 min | | 2h 30 min | +------------+ 2 rows in set ... Read More

No, you need to use open and close parenthesis like this ( ) while creating a table. Use the below syntax −CREATE TABLE IF NOT EXISTS yourTableName (    yourColumnName1 dataType1,    .    .    .    .    .    N );Let us first create a table −mysql> CREATE TABLE IF NOT EXISTS DemoTable    (    CustomerId int,    CustomerName varchar(20),    CustomerAge int    ,    PRIMARY KEY(CustomerId)    ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1, 'Chris', 25); Query OK, 1 row ... Read More

Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Subject varchar(20),    Price int    ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Subject, Price) values('MySQL', 456); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(Subject, Price) values('MySQL', 456); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Subject, Price) values('MongoDB', 56); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(Subject, Price) values('MongoDB', 60); Query OK, 1 row affected (0.13 sec) mysql> ... Read More

For this, use the LIKE operator. Let us first create a table:mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Password varchar(100)    ); Query OK, 0 rows affected (1.27 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Password) values('John@--123'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable(Password) values('---Carol234'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Password) values('--David987'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(Password) values('Mike----53443'); Query OK, 1 row affected (0.30 sec)Display all records from the table using select ... Read More

To fund a value from JSON data, use the find() along with dot(.) notation. Let us first create a collection with documents −> db.findValueFromJsonDemo.insertOne(    {       "UserDetails": [{          "_id": new ObjectId(),          "UserName": "Carol",          "UserMessage": "Hi"       }],       "UserFriendsName": ["John", "Sam"]    } ); {    "acknowledged" : true,    "insertedId" : ObjectId("5cdf8a4cbf3115999ed511fd") }Following is the query to display all documents from a collection with the help of find() method −> db.findValueFromJsonDemo.find().pretty();This will produce the following output −{    "_id" : ... Read More