The @ symbol in a stored procedure can be used for user-defined session variables. Let us first create a table −mysql> create table DemoTable (    StudentName varchar(50) ); Query OK, 0 rows affected (1.30 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John Smith'); Query OK, 1 row affected (1.00 sec) mysql> insert into DemoTable values('John Doe'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Chris Brown'); Query OK, 1 row affected (0.53 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output ... Read More

Let us first create a table −mysql> create table DemoTable (    FirstName varchar(100),    LastName varchar(100) ); Query OK, 0 rows affected (0.83 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Adam', 'Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('John', 'Doe'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('John', 'Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Chris', 'Brown'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('Robert', 'Brown'); Query OK, 1 row affected (0.10 sec) mysql> insert ... Read More

For this, you can use the property IS NULL for null values in MySQL. Let us first create a table −mysql> create table DemoTable (    Name varchar(100) ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(null); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(null); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 ... Read More

Let us first create a table −mysql> create table DemoTable (    Id int,    ColorName varchar(100) ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 'Red'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(101, 'Green'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(101, 'Blue'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable values(102, 'Yellow'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(100, 'Purple'); Query OK, 1 row affected (0.12 sec) mysql> insert ... Read More

Let us first create a table. Here, we have VARCHAR type for value −mysql> create table DemoTable (    Value varchar(100) ); Query OK, 0 rows affected (1.80 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('100'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('1244'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('15789'); Query OK, 1 row affected (0.18 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+-------+ | Value | +-------+ | 100 | ... Read More

Let us first create a table −mysql> create table DemoTable (    Price int,    Quantity int ); Query OK, 0 rows affected (0.71 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(45, 3); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(90, 2); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(440, 1); Query OK, 1 row affected (0.09 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+-------+----------+ | Price | Quantity | +-------+----------+ | ... Read More

Let us first create a table −mysql> create table DemoTable1 (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Name varchar(100) ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1(Name) values('Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1(Name) values('Robert'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1(Name) values('Mike'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1(Name) values('Sam'); Query OK, 1 row affected (0.07 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce ... Read More

Let us first create a table −mysql> create table DemoTable (    AdmissionDate date ); Query OK, 0 rows affected (0.87 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-08-24'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('2019-08-25'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('2019-08-20'); Query OK, 1 row affected (0.24 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+---------------+ | AdmissionDate | +---------------+ | 2019-08-24 | | 2019-08-25 | ... Read More

Following is the syntax −select *from yourTableName order by yourColumnName*1, yourColumnName;Let us first create a table −mysql> create table DemoTable (    Value varchar(100) ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('90'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('86'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('45'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('85'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('085'); Query OK, 1 row affected (0.14 sec) ... Read More

Following is the syntax −select if(yourColumnName, 1, -1) from yourTableName;Let us first create a table −mysql> create table DemoTable (    isMarried boolean ); Query OK, 0 rows affected (0.60 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(true); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(false); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(false); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(true); Query OK, 1 row affected (0.36 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will ... Read More