To set all the values in a field to 0, use the update command −update yourTableName set yourColumnName=0;Let us first create a table −mysql> create table DemoTable    (    Number int    ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(4757); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(48474); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values(35465); Query OK, 1 row affected (0.16 sec)Display all records from ... Read More

Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(20)    ); Query OK, 0 rows affected (1.23 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(StudentName) values('John'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable(StudentName) values('Carol'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(StudentName) values('David'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(StudentName) values('Bob'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(StudentName) values('Chris'); Query OK, 1 row affected (0.12 sec) ... Read More

To get the last days of all the months, use the LAST_DAY() function from MySQL −SELECT LAST_DAY(yourColumnName) from yourTableName;Let us first create a table −mysql> create table DemoTable    (    ShippingDate date    ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-01-12'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('2019-02-01'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('2019-03-04'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('2019-04-21'); Query OK, 1 row affected (0.14 sec)Display all records ... Read More

Use the concept of DATE_SUB(). Let us first create a table −mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    ArrivalDate datetime    ); Query OK, 0 rows affected (1.02 sec)Note: Let’s say the current date is 2019-06-08Insert some records in the table using insert command −mysql> insert into DemoTable(ArrivalDate) values('2019-05-15'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(ArrivalDate) values('2019-06-08'); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable(ArrivalDate) values('2019-05-20'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(ArrivalDate) values('2019-05-12'); Query OK, 1 row affected (0.12 sec)Display ... Read More

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