Found 4218 Articles for MySQLi

Selecting all the users with maximum age values using a MySQL subquery?

AmitDiwan
Updated on 24-Sep-2019 13:54:18

365 Views

Let us first create a table −mysql> create table DemoTable (    Name varchar(100),    Age int ); Query OK, 0 rows affected (0.46 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 23); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('David', 55); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Bob', 53); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values('Mike', 54); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values('Sam', 55); Query OK, 1 row affected (0.18 sec)Display all records ... Read More

How to remove duplicate values from a MySQL table using LEFT JOIN?

AmitDiwan
Updated on 24-Sep-2019 13:43:38

591 Views

Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    FirstName varchar(100) ); Query OK, 0 rows affected (0.46 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FirstName) values('Chris'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(FirstName) values('Robert'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(FirstName) values('Robert'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.11 sec) mysql> insert ... Read More

How to concatenate strings from different columns and an additional string using a MySQL query?

AmitDiwan
Updated on 24-Sep-2019 13:41:30

126 Views

Let us first create a table −mysql> create table DemoTable (    FirstName varchar(100),    LastName varchar(100) ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 'Brown'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Adam', 'Smith'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Carol', 'Taylor'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('David', 'Miller'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the ... Read More

How to update a field with a particular value if it is null in MySQL?

AmitDiwan
Updated on 24-Sep-2019 13:10:08

1K+ Views

To update a field if it is null, use IS NULL property along with the UPDATE command. Let us first create a table −mysql> create table DemoTable (    StudentScore int ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(89); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(NULL); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(45); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(NULL); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(56); ... Read More

Insert values from the first table to the second table using two SELECT statements in a single MySQL query

AmitDiwan
Updated on 24-Sep-2019 13:08:03

303 Views

To insert values from the first table to another table using two SELECT statements, use SUBQUERY. This will allow you to use only a single MySQL query to get the result in the second table. Let us first create a table −mysql> create table DemoTable1 (    Name varchar(100),    Score int ); Query OK, 0 rows affected (1.30 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values('Chris', 45); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1 values('Bob', 78); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1 values('David', 98); ... Read More

How to ORDER BY FIELD with GROUP BY in a single MySQL query?

AmitDiwan
Updated on 24-Sep-2019 13:05:27

316 Views

For this, let us first create a table −mysql> create table DemoTable (    Message text ); Query OK, 0 rows affected (1.15 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Good'); Query OK, 1 row affected (0.43 sec) mysql> insert into DemoTable values('Bye'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Awesome'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Bye'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('Good'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values('Amazing'); Query OK, 1 ... Read More

How to set MySQL default value NONE?

AmitDiwan
Updated on 24-Sep-2019 13:03:19

783 Views

To set the default value in MySQL, you need to use the DEFAULT keyword. Let us first create a table −mysql> create table DemoTable (    ClientCountryName varchar(100) DEFAULT 'NONE' ); Query OK, 0 rows affected (0.65 sec)We have set DEFAULT above for values not entered while insertion. Now, let us insert some records in the table using the insert command. We haven’t inserted values here for some of the rows. The DEFAULT gets set there −mysql> insert into DemoTable values('US'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.09 sec) ... Read More

MySQL select statement to fetch 5 characters from the left of the string

AmitDiwan
Updated on 24-Sep-2019 13:01:07

257 Views

To fetch number of characters from the left of the string, use the LEFT method in MySQL. Let us first create a table −mysql> create table DemoTable (    Name varchar(100) ); Query OK, 0 rows affected (6.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Sam Brown'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('David Miller'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('Adam Smith'); Query OK, 1 row affected (7.01 sec) mysql> insert into DemoTable values('Carol Taylor'); Query OK, 1 row affected (0.68 sec)Display all ... Read More

Can we use SELECT NULL statement in a MySQL query?

AmitDiwan
Updated on 24-Sep-2019 12:56:07

255 Views

Yes, we can use the SELECT NULL statement in a MySQL query. Let us first create a table −mysql> create table DemoTable (    Name varchar(100) ); 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 (0.47 sec) mysql> insert into DemoTable values('Mike'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values('Sam'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Bob'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected ... Read More

Update only a single value from a MySQL table where select from same table ordered in descending order?

AmitDiwan
Updated on 24-Sep-2019 12:53:55

102 Views

For this, use ORDER BY DESC with the LIMIT clause. The ORDER BY DESC order in descending order where LIMIT sets the number of records you want. Here, we will set LIMIT 1 since we want only a single record. Let us first create a table −mysql> create table DemoTable (    StudentName varchar(100),    StudentMarks int ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 45); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('Bob', 78); Query OK, 1 row affected (0.16 sec) mysql> ... Read More

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