Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
MySQL Articles
Page 220 of 355
How to update a field with a particular value if it is null in MySQL?
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 MoreInsert values from the first table to the second table using two SELECT statements in a single MySQL query
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 MoreHow to ORDER BY FIELD with GROUP BY in a single MySQL query?
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 MoreHow to set MySQL default value NONE?
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 MoreCan we use SELECT NULL statement in a MySQL query?
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 MoreUpdate only a single value from a MySQL table where select from same table ordered in descending order?
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 MoreReturn true or false in a MySQL select if another field contains a string?
To return TRUE or FALSE if another field contains a string, use IF(). Let us first create a tablemysql> create table DemoTable ( FirstName varchar(100), LastName varchar(100) ); Query OK, 0 rows affected (1.28 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 'Brown'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('David', 'Miller'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Adam', 'Smith'); Query OK, 1 row affected (0.11 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following ...
Read MoreHow to get a value more than a particular value from varchar column in MySQL?
Since the column wherein you want to get the value more than a particular value is VARCHAR, use the CAST() function. For example, to fetch the value more than 999 from a column with varchar values.Let us first create a table −mysql> create table DemoTable ( Value varchar(100) ); Query OK, 0 rows affected (1.02 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('900'); Query OK, 1 row affected (0.49 sec) mysql> insert into DemoTable values('1090'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('860'); Query OK, 1 row affected (0.25 ...
Read MoreMySQL query to check if a string contains a value (substring) within the same row?
Since we need to match strings from the same row, use LIKE operator. Let us first create a table −mysql> create table DemoTable ( FirstName varchar(100), FullName varchar(100) ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John', 'John Smith'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('David', 'John Miller'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Bob', 'Sam Miller'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Chris', 'Chris Brown'); Query OK, 1 row affected ...
Read MoreCan 'false' match some string in MySQL?
Yes, you can use false as 0 to match.Let us first create a table −mysql> create table DemoTable804 ( Id varchar(100) ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable804 values('101John'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable804 values('Carol1002'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable804 values('1000'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable804 values('1010Bob'); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement −mysql> select *from DemoTable804;This ...
Read More