For this, you can use substring() function in MySQL. For conditions, use MySQL CASE statement. Let us first create a −mysql> create table DemoTable1402    -> (    -> EmployeeName varchar(40)    -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert −mysql> insert into DemoTable1402 values('Adam Smith'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1402 values('Chris Brown'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1402 values('David Miller'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1402 values('Carol Taylor'); Query OK, 1 row affected (0.10 sec)Display ... Read More

Backticks would work if written correctly as in the below syntax −update `yourTableName` set `yourTableName`.`yourColumnName`='yourNewValue' where yourCondition;Let us first create a −mysql> create table `DemoTable_1401`    -> (    -> Name varchar(20)    -> ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert −mysql> insert into `DemoTable_1401` values('Chris'); Query OK, 1 row affected (0.16 sec) mysql> insert into `DemoTable_1401` values('David'); Query OK, 1 row affected (0.10 sec) mysql> insert into `DemoTable_1401` values('Bob'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select −mysql> select * from `DemoTable_1401`;This will produce the ... Read More

Each relation may have one or more candidate key. One of these candidate keys is called Primary Key. Each candidate key qualifies for Primary Key. Therefore, candidates for Primary Key is called Candidate Key. To implement candidate key in MySQL, set more than one column as unique key. These keys would qualify for candidate key as in the below syntax −alter table yourTableName add unique key anyName(yourColumnName1, yourColumnName2);Let us first create a −mysql> create table DemoTable1400    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(40),    -> Age int    -> ); Query ... Read More

No, it is possible to get the next primary key without adding a new record. Let us first create a −mysql> create table DemoTable1399    -> (    -> StudentId int NOT NULL AUTO_INCREMENT,    -> PRIMARY KEY(StudentId)    -> ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert −mysql> insert into DemoTable1399 values(); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1399 values(); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1399 values(); Query OK, 1 row affected (0.07 sec)Display all records from the table using select −mysql> select ... Read More

Let us first create a −mysql> create table DemoTable1398    -> (    -> Marks int    -> ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert −mysql> insert into DemoTable1398 values(78); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1398 values(82); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1398 values(90); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1398 values(98); Query OK, 1 row affected (0.12 sec)Display all records from the table using select −mysql> select * from DemoTable1398;This will produce the following output −+-------+ | ... Read More

For date comparison, you can use STR_TO_DATE(). Following is the syntax −select * from yourTableName where str_to_date(yourColumnName, 'yourFormatSpecifier') > curdate();Let us first create a −mysql> create table DemoTable1397    -> (    -> AdmissionDate varchar(40)    -> );s Query OK, 0 rows affected (0.97 sec)Insert some records in the table using insert −mysql> insert into DemoTable1397 values('01/04/2019'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1397 values('27/09/2019'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1397 values('29/09/2018'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1397 values('29/09/2019'); Query OK, 1 row affected (0.08 sec)Display ... Read More

Let us first create a −mysql> create table DemoTable1396    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(40),    -> Age int    -> ); Query OK, 0 rows affected (0.93 sec)Insert some records in the table using insert −mysql> insert into DemoTable1396(Name, Age) values('Chris', 21); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1396(Name, Age) values('David', 24); Query OK, 1 row affected (0.34 sec) mysql> insert into DemoTable1396(Name, Age) values('Bob', 26); Query OK, 1 row affected (0.40 sec)Display all records from the table using select −mysql> select * from DemoTable1396;This ... Read More

Let us first create a −mysql> create table DemoTable1    -> (    -> Id int    -> ); Query OK, 0 rows affected (1.06 sec)Insert some records in the table using insert −mysql> insert into DemoTable1 values(1); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1 values(NULL); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1 values(2); Query OK, 1 row affected (0.34 sec) mysql> insert into DemoTable1 values(3); Query OK, 1 row affected (0.13 sec)Display all records from the table using select −mysql> select * from DemoTable1;This will produce the following output −+------+ | ... Read More

To sort multiple columns, use ORDER BY GREATEST(). Let us first create a −mysql> create table DemoTable1395    -> (    -> Value1 int,    -> Value2 int,    -> Value3 int    -> ); Query OK, 0 rows affected (0.79 sec)Insert some records in the table using insert −mysql> insert into DemoTable1395 values(40, 50, 60); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1395 values(90, 56, 80); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1395 values(10, 20, 30); Query OK, 1 row affected (0.11 sec)Display all records from the table using select −mysql> select ... Read More

For thousands number, use MySQL FORMAT(). Let us first create a −mysql> create table DemoTable1394    -> (    -> Amount decimal(7, 3)    -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert −mysql> insert into DemoTable1394 values(60); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1394 values(2355.4); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable1394 values(456); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1394 values(8769); Query OK, 1 row affected (0.13 sec)Display all records from the table using select −mysql> select * from DemoTable1394;This ... Read More