To insert a NULL value, you can use UPDATE command. Following is the syntax −UPDATE yourTableName SET yourColumnName=NULL;Let us first create a table −mysql> create table insertNullValue    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> ClientName varchar(100),    -> ClientCountryName varchar(20)    -> ); Query OK, 0 rows affected (0.54 sec)Following is the query to insert some records in the table using insert command −mysql> insert into insertNullValue(ClientName, ClientCountryName) values('Larry', 'US'); Query OK, 1 row affected (0.19 sec) mysql> insert into insertNullValue(ClientName, ClientCountryName) values('David', 'AUS'); Query OK, 1 row affected (0.09 sec) ... Read More

If you want to check privileges for a specific user, then use the below syntax −SHOW GRANTS FOR 'yourUserName'@'yourHostName';The above syntax will check privileges for a specific user.To check the privileges for a specific user, then use FOR. Let’s say we have a username ‘JOHN‘ and host is ‘%’. Following is the query to get the privileges for user “JOHN” −mysql> SHOW GRANTS FOR 'JOHN'@'%';This will produce the following output −+--------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------- --------------+ | Grants for JOHN@% | +--------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------- --------------+ | GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, ... Read More

To remove NULL records in a column, you can use delete command. Following is the syntax −delete from yourTableName where yourColumnName IS NULL;Let us first create a table −mysql> create table removeNullRecordsDemo    -> (    -> Name varchar(100)    -> ); Query OK, 0 rows affected (0.50 sec)Following is the query to insert records in the table using insert command −mysql> insert into removeNullRecordsDemo values('John'); Query OK, 1 row affected (0.14 sec) mysql> insert into removeNullRecordsDemo values(null); Query OK, 1 row affected (0.15 sec) mysql> insert into removeNullRecordsDemo values('Larry'); Query OK, 1 row affected (0.19 sec) ... Read More

You can use LPAD() from MySQL to pad the beginning of a MySQL INT field with zeroes. Let us first create a table.mysql> create table paddingDemo    -> (    -> Number int    -> ); Query OK, 0 rows affected (0.49 sec)Following is the query to insert some records in the table using insert command −mysql> insert into paddingDemo values(78); Query OK, 1 row affected (0.14 sec) mysql> insert into paddingDemo values(560); Query OK, 1 row affected (0.17 sec) mysql> insert into paddingDemo values(888995); Query OK, 1 row affected (0.13 sec) mysql> insert into paddingDemo values(999994); ... Read More

In order to remove partial text from value, you can use REPLACE() from MySQL. Following is the syntax −update yourTableName set yourColumnName = replace(yourColumnName ,'yourValue ', '' );Let us first create a table −mysql> create table removePartialTextDemo    -> (    -> JavaVersionDetails varchar(100)    -> ); Query OK, 0 rows affected (0.51 sec)Following is the query to insert some records in the table using insert command −mysql> insert into removePartialTextDemo values('Java Version 1.0'); Query OK, 1 row affected (0.50 sec) mysql> insert into removePartialTextDemo values('Java Version 1.1'); Query OK, 1 row affected (0.23 sec) mysql> insert into ... Read More

For this, use ORDER BY along with GROUP BY clause. Let us first create a table with Student Name and Score −mysql> create table countRowValueDemo    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(20),    -> StudentMathScore int    -> ); Query OK, 0 rows affected (0.71 sec)Following is the query to insert records in the table using insert command −mysql> insert into countRowValueDemo(StudentName, StudentMathScore) values('Larry', 45); Query OK, 1 row affected (0.19 sec) mysql> insert into countRowValueDemo(StudentName, StudentMathScore) values('Mike', 56); Query OK, 1 row affected (0.16 sec) mysql> insert into ... Read More

Assume that the date is in varchar data type i.e. not in the date format.Let us first create a table. Following is the query −mysql> create table convertDateDemo    -> (    -> AdmissionDate varchar(200)    -> ); Query OK, 0 rows affected (0.63 sec)Following is the query to insert some records in the table using insert command −mysql> insert into convertDateDemo values('April 04 2019'); Query OK, 1 row affected (0.18 sec) mysql> insert into convertDateDemo values('May 05 2018'); Query OK, 1 row affected (0.16 sec) mysql> insert into convertDateDemo values('January 01 2012'); Query OK, 1 row affected ... Read More

You can display databases sorted by creation date with ORDER BY clause. Following is the query to display all databases −mysql> show databases;This will produce the following output −+---------------------------+ | Database                  | +---------------------------+ | bothinnodbandmyisam       | | business                  | | commandline               | | customer_tracker_database | | customertracker           | | database1                 | | databasesample            | | demo ... Read More

Let us first create a table. Following is the query −mysql> create table gettingAndOrderingRowsDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Value int    -> ); Query OK, 0 rows affected (1.35 sec)Following is the query to insert some records in the table using insert command −mysql> insert into gettingAndOrderingRowsDemo(Value) values(10); Query OK, 1 row affected (0.33 sec) mysql> insert into gettingAndOrderingRowsDemo(Value) values(13); Query OK, 1 row affected (0.32 sec) mysql> insert into gettingAndOrderingRowsDemo(Value) values(0); Query OK, 1 row affected (0.17 sec) mysql> insert into gettingAndOrderingRowsDemo(Value) values(20); Query OK, 1 ... Read More

In order to check a table exists in MySQL, you can use INFORMATION_SCHEMA.TABLES. Let us first create a table −mysql> create table Client_information    -> (    -> Id int,    -> Name varchar(10)    -> ); Query OK, 0 rows affected (0.48 sec)Following is the query to insert some records in the table using insert command −mysql> insert into Client_information values(1, 'Larry'); Query OK, 1 row affected (0.14 sec) mysql> insert into Client_information values(2, 'Mike'); Query OK, 1 row affected (0.17 sec) mysql> insert into Client_information values(3, 'Sam'); Query OK, 1 row affected (0.19 sec)Following is the ... Read More