For this, use COALESCE() function from MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> Value1 int, -> Value2 int -> ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 200); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values(NULL, 90); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(NULL, NULL); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(600, NULL); Query OK, 1 row affected (0.12 sec)Display all records from ... Read More

Let us first create a table −mysql> create table DemoTable -> ( -> Amount int -> ); Query OK, 0 rows affected (0.99 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(200); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(500); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+--------+ | Amount | +--------+ | 100 | | 200 ... Read More

For this, use CASE statement. Let us first create a table −mysql> create table DemoTable -> ( -> Title text -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('My name is John and this is my first tutorial on MySQL'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('This is Carol and I work on MongoDB'); Query OK, 1 row affected (0.19 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+--------------------------------------------------------+ | Title ... Read More

Let us first create a table −mysql> create table DemoTable    -> (    -> Id int,    -> Score int    -> ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1, 858858686); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(2, 9900554); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(3, 646565667); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+------+-----------+ | Id ... Read More

To swap data between two columns in MySQL, use the concept of variable. Let us first create a table. Here, we will swap Name1 with Name2 −mysql> create table DemoTable -> ( -> Name1 varchar(100), -> Name2 varchar(100) -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John Smith', 'Chris Brown'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('David Miller', 'Jone Doe'); Query OK, 1 row affected (0.16 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce ... Read More

Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(100), -> Score int -> ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name, Score) values('John', 68); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(Name, Score) values('Carol', 98); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable(Name, Score) values('David', 89); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(Name, Score) values('Robert', 67); Query OK, 1 row affected ... Read More

For this, you can use UNION. Let us first create a table −mysql> create table DemoTable -> ( -> Number int -> ); Query OK, 0 rows affected (1.17 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(-9); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(-190); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(190); Query OK, 1 row affected ... Read More

Use ORDER BY and set DESC to order by desc. However, to get all the values except a single value, use the not equal operator.Let us first create a table −mysql> create table DemoTable    -> (    -> Name varchar(100)    -> ); Query OK, 0 rows affected (0.89 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Sam'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.15 sec) mysql> insert ... Read More

Use INSERT() function from MySQL. It has the following parameters −ParameterDescriptionstrString to be modifiedpositionPosition where to insert str2numberNumber of characters to replacestr2String to insert into strLet us first create a table −mysql> create table DemoTable    -> (    -> Code varchar(100)    -> ); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('958575/98') ; Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('765432/99'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('983456/91'); Query OK, 1 row affected (0.15 sec)Display all ... Read More

Use ALTER for this with ADD. Following is the syntax −alter table yourTableName add yourColumnName DATETIME DEFAULT NOW(), add index(yourColumnName);Let us first create a table −mysql> create table DemoTable    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(100),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.69 sec)Let us check the description of the table −mysql> desc DemoTable;OutputThis will produce the following output −+-------+--------------+------+-----+---------+----------------+ | Field | Type         | Null | Key | Default | Extra          | +-------+--------------+------+-----+---------+----------------+ | Id    | int(11) ... Read More