At first, to use reserved words, it should be set with backticks like −`from` `to`Since you want to select the column names set with backtick as shown above, you need to implement the following −select `to`, `from` from yourTableName;Let us first create a table with column names as from and to with backticks −mysql> create table DemoTable720 (    `from` date,    `to` date ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command −mysql> insert into DemoTable720 values('2019-01-21', '2019-07-23'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable720 values('2017-11-01', '2018-01-31'); Query ... Read More

Use trigger BEFORE INSERT on the table to prevent having a zero value in a MySQL field. Let us first create a table −mysql> create table DemoTable(Value int); Query OK, 0 rows affected (0.85 sec)Let us create a trigger to prevent having a zero value in a MySQL field −mysql> DELIMITER // mysql> create trigger preventing_to_insert_zero_value    before insert on DemoTable    for each row    begin       if(new.Value = 0) then SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'You can not provide 0 value';    END if; end // Query OK, 0 rows affected (0.34 sec) mysql> DELIMITER ... Read More

The slash means division ( /) in MySQL query. This can be used to divide two numbers. Here, we will see an example to divide numbers from two columns and display result in a new column.Let us first create a table −mysql> create table DemoTable719 (    FirstNumber int,    SecondNumber int ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable719 values(20, 10); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable719 values(500, 50); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable719 values(400, 20); ... Read More

For this, you can use NOT IN() function.Let us first create a table −mysql> create table DemoTable718 (    Id int,    FirstName varchar(100),    Age int ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable718 values(101, 'Chris', 26); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable718 values(102, 'Robert', 24); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable718 values(103, 'David', 27); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable718 values(104, 'Mike', 28); Query OK, 1 row affected (0.19 sec) mysql> ... Read More

Let us first create a table −mysql> create table DemoTable717 (    UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    UserPassword int ); Query OK, 0 rows affected (0.81 sec)Insert some records in the table using insert command −mysql> insert into DemoTable717(UserPassword) values(1454343); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable717(UserPassword) values(674654); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable717(UserPassword) values(989883); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable717(UserPassword) values(909983); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable717;This will produce ... Read More

Let us first create a table −mysql> create table DemoTable716 (    Id varchar(100),    Value1 int,    Value2 int,    Value3 int ); Query OK, 0 rows affected (0.65 sec)Insert some records in the table using insert command −mysql> insert into DemoTable716 values('100', 45, 86, 79); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable716 values('101', 67, 67, 99); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable716 values('102', 77, 57, 98); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable716 values('103', 45, 67, 92); Query OK, 1 row affected (0.16 sec)Display all ... Read More

For this, you can use ORDER BY IF(CAST()). Let us first create a table −mysql> create table DemoTable(EmployeeCode varchar(100)); Query OK, 0 rows affected (1.17 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('190'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('100'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values('120'); Query OK, 1 row affected (0.21 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+--------------+ ... Read More

To order by length of column in MySQL, use ORDER BY LENGTH.Let us first create a table −mysql> create table DemoTable715 (UserMessage varchar(100)); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable715 values('Aw'); Query OK, 1 row affected (0.49 sec) mysql> insert into DemoTable715 values('Awe'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable715 values('A'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable715 values('Awes'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable715 values('Awesom'); Query OK, 1 row affected (0.16 sec) mysql> insert ... Read More

Let us first create a table −mysql> create table DemoTable1 (FirstName varchar(100)); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values('Bob'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable1 values('James'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1 values('John'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable1 values('David'); Query OK, 1 row affected (0.18 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce the following output -+-----------+ | FirstName | +-----------+ | Bob ... Read More

Let us first create a table −mysql> create table DemoTable    (       Id int,       Name varchar(100)    ); Query OK, 0 rows affected (1.40 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 'John'); Query OK, 1 row affected (0.44 sec) mysql> insert into DemoTable values(101, 'Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(102, 'Chris'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(103, 'Chris'); Query OK, 1 row affected (1.05 sec) mysql> insert into DemoTable values(104, 'David'); Query OK, 1 ... Read More