MySQLi Articles - Page 105 of 422

To get the last date i.e. the latest, use aggregate function MAX() with a subquery. Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    ExpiryDate date ); Query OK, 0 rows affected (1.40 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(ExpiryDate) values('2018-12-31'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(ExpiryDate) values('2019-09-01'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(ExpiryDate) values('2019-09-01'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(ExpiryDate) values('2016-08-30'); Query OK, 1 row affected (0.13 ... Read More

Yes, use AUTO_INCREMENT with PRIMARY KEY. Let us first create a table −mysql> create table DemoTable (    EmployeeId int NOT NULL AUTO_INCREMENT,    EmployeeName varchar(40),    EmployeeAge int,    PRIMARY KEY(EmployeeId),    UNIQUE KEY(EmployeeName, EmployeeAge) ); Query OK, 0 rows affected (0.96 sec)Let us check the table description of the table −mysql> desc DemoTable;This will produce the following output −+--------------+-------------+------+-----+---------+----------------+ | Field        | Type        | Null | Key | Default | Extra          | +--------------+-------------+------+-----+---------+----------------+ | EmployeeId   | int(11)     | NO   | PRI | NULL   ... Read More

For this, you can use a subquery. Let us first create a table −mysql> create table DemoTable (    Score int ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(80); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(45); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(55); Query OK, 1 row affected (0.33 sec) mysql> insert into DemoTable values(78); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.13 sec)Display all records from ... Read More

For this, use the GROUP BY HAVING clause. Let us first create a table −mysql> create table DemoTable (    Value int ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(99); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(99); Query OK, 1 row affected (0.09 sec) mysql> insert ... Read More

To count comma-separated-values, use aggregate function COUNT(*) along with FIND_IN_SET(). Let us first create a table −mysql> create table DemoTable (    Value varchar(100) ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('10, 20, 60, 80'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('60, 70, 90'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('50, 55, 65, 60'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('90, 98, 97'); Query OK, 1 row affected (0.12 sec)Display all records ... Read More

For this, use the INSERT() function from MySQL. The INSERT(str, pos, len, newstr) returns the string str, with the substring beginning at position pos and len characters long replaced by the string newstr. Returns the original string if pos is not within the length of the string.It replaces the rest of the string from position pos if len is not within the length of the rest of the string. Returns NULL if any argument is NULL.Let us first create a table −mysql> create table DemoTable (    Password varchar(50) ); Query OK, 0 rows affected (0.51 sec)Insert some records in ... Read More

Let us first create a table −mysql> create table DemoTable (    Name varchar(40),    Score int ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Adam', 89); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Adam', 89); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Chris', 89); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Chris', 89); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Bob', 98); Query OK, 1 row affected (0.10 sec) mysql> insert ... Read More

For this, you can use subquery. Let us first create a table −mysql> create table DemoTable (    StudentName varchar(40),    StudentMarks int ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Adam', 56); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Chris', 78); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Adam', 89); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Robert', 98); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Chris', 65); Query OK, 1 ... Read More

To generate a row index, use ROW_NUMBER(). Let us first create a table −mysql> create table DemoTable (    Name varchar(40) ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.14 sec) mysql> insert into ... Read More

Use CREATE TABLE IF NOT EXISTS for this as shown in the below syntax −create table if not exists yourTableName (    yourColumnName1 dataType,    yourColumnName2 dataType,    yourColumnName3 dataType,    .    .    N ) as select yourValue1 as yourColumnName1 , yourValue2 as yourColumnName2 , yourValue3 as yourColumnName3, .............................N;Let us first create a table and insert value if the table does not already exist −mysql> create table if not exists DemoTable (    id int,    FirstName varchar(20),    LastName varchar(20) ) as select 100 as id, 'John' as FirstName , 'Smith' as LastName; Query OK, 1 row ... Read More