The TIMESTAMP data type is used for values containing both date and time parts. Let us first create a table −mysql> create table DemoTable662(    UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, UserName varchar(100), UserPostDate datetime ); Query OK, 0 rows affected (0.50 sec)Following is the query for valid default timestamp values −mysql> alter table DemoTable662 MODIFY COLUMN UserPostDate TIMESTAMP NOT NULL DEFAULT current_timestamp; Query OK, 0 rows affected (1.81 sec) Records: 0 Duplicates: 0 Warnings: 0Let us check the description of table once again −mysql> desc DemoTable662;This will produce the following output −+--------------+--------------+------+-----+-------------------+----------------+ | Field        | ... Read More

The OR operator gives true result when any one operand is true. Let us now see an example and create a table −mysql> create table DemoTable663(ClientId int, ClientName varchar(100), ClientAge int); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable663 values(100, 'Chris', 45); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable663 values(101, 'Robert', 29); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable663 values(102, 'John', 45); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable663 values(103, 'Chris', 35); Query OK, 1 row affected ... Read More

Let us first create a table and set default values −mysql> create table DemoTable803(UserId int DEFAULT 101, UserName varchar(100) DEFAULT 'Chris'); Query OK, 0 rows affected (1.18 sec)Insert some records in the table using insert command. For the values we are not inserting, the default values will get set automatically −mysql> insert into DemoTable803 values(102, 'Chris'); Query OK, 1 row affected (0.34 sec) mysql> insert into DemoTable803(UserName) values('Mike'); Query OK, 1 row affected (0.48 sec) mysql> insert into DemoTable803(UserId) values(103); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable803 values(); Query OK, 1 row affected (0.22 sec) mysql> ... Read More

To extract from datetime column, you can use date() along with trim(). Here, trim() is used to remove whitespace while comparing. Let us first create a table −mysql> create table DemoTable661(Duedate datetime); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable661 values(' 2019-01-21 12:02:21'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable661 values(' 2019-07-11 11:55:59 '); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable661 values('2019-11-21 04:00:59 '); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement −mysql> select ... Read More

Yes, you can use date_sub() to subtract number of days from a date. Following is the syntax −select date_sub(yourColumnName, Interval yourAmountOfDays day) from yourTableName;Let us first create a table −mysql> create table DemoTable660(AdmissionDate datetime); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable660 values('2018-01-24'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable660 values('2019-07-10'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable660 values('2020-11-20'); Query OK, 1 row affected (0.59 sec)Display all records from the table using select statement −mysql> select *from DemoTable660;This will produce the ... Read More

To fetch a specific row when values are the same, use GROUP BY. Let us first create a table −mysql> create table DemoTable659(Id int, Name varchar(100), Score int); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into DemoTable659 values(11, 'John', 45); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable659 values(15, 'John', 59); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable659 values(15, 'Sam', 61); Query OK, 1 row affected (0.14 sec)Display all records from the table using select statement −mysql> select *from DemoTable659;This will produce the ... Read More

Let us first create a table −mysql> create table DemoTable658(FirstName varchar(100),value char(2)); Query OK, 0 rows affected (0.95 sec)Insert some records in the table using insert command −mysql> insert into DemoTable658(FirstName) values('John') ; Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable658(value,FirstName) values(default(value),'Sam'); Query OK, 1 row affected (0.23 sec)Display all records from the table using select statement −mysql> select *from DemoTable658;This will produce the following output −+-----------+-------+ | FirstName | value | +-----------+-------+ | John     | NULL | | Sam     | NULL | +-----------+-------+ 2 rows in set (0.00 sec)

Here, we are converting time value, for example 150:50:10 to days and hours form, i.e. 6 days 6 hours.You can use CONCAT() along with HOUR() for this. Let us first create a table −mysql> create table DemoTable657(DueTime time); Query OK, 0 rows affected (3.68 sec)Insert some records in the table using insert command. Here, we have inserted the records in the form of total hours −mysql> insert into DemoTable657 values('120:30:00'); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable657 values('150:50:10'); Query OK, 1 row affected (0.27 sec)Display all records from the table using select statement −mysql> select *from ... Read More

You can use SELECT *FROM yourTableName in stored procedure. Let us first create a table −mysql> create table DemoTable654 (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentFirstName varchar(100) ); Query OK, 0 rows affected (0.70 sec)Insert some records in the table using insert command −mysql> insert into DemoTable654(StudentFirstName) values('John'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable654(StudentFirstName) values('Sam'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable654(StudentFirstName) values('Mike'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable654(StudentFirstName) values('Robert'); Query OK, 1 row affected (0.12 sec)Display all records from the table using ... Read More

To change order of items in MySQL, use ORDER BY alias name. Let us first create a table −mysql> create table DemoTable653 (Product1Amount int, Product2Amount int); Query OK, 0 rows affected (0.42 sec)Insert some records in the table using insert command −mysql> insert into DemoTable653 values(400, 250); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable653 values(500, 300); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable653 values(40, 400); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable653 values(200, 450); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable653 values(50, 20); Query ... Read More