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
Articles by George John
Page 73 of 79
How to form a MySQL Conditional Insert?
For this, you can insert using MySQL dual table. Let us create a table to understand the concept conditional insert. The query to create a table is as follows −mysql> create table ConditionalInsertDemo -> ( -> UserId int, -> TotalUser int, -> NumberOfItems int -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into ConditionalInsertDemo values(101, 560, 780); Query OK, 1 row affected (0.19 sec) mysql> insert into ConditionalInsertDemo values(102, 660, 890); Query OK, 1 row affected (0.20 sec) ...
Read MoreWhy the G modifier in SELECT * FROM table_nameG?
The \G modifier gets the result in vertical order. If you use \g modifier, then it won’t affect the result. The \g works likesemi-colon.Let us first create a table. The query to create a table is as follows:mysql> create table DemoOfVertical -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(20), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (3.40 sec)Now you can insert some records in the table using insert command. The query is as follows:mysql> insert into DemoOfVertical(Name) values('Bob'); Query OK, 1 row affected (0.18 sec) mysql> insert into ...
Read MoreMySQL: selecting rows where a column is null?
To select rows where a column is null, you can use IS NULL from MySQL with the help of where clause.The syntax is as follows −select *from yourTableName where yourColumnName IS NULL;Let us first create a table to understand the concept −mysql> create table NULLDemo1 -> ( -> StudentId int, -> StudentName varchar(100) -> ); Query OK, 0 rows affected (1.48 sec)Inserting records into the table. The query to insert records is as follows −mysql> insert into NULLDemo1 values(NULL, 'John'); Query OK, 1 row affected (0.25 sec) mysql> ...
Read MoreHow to select all records that are 10 minutes within current timestamp in MySQL?
You can select all records that are 10 minutes within current timestamp using the following syntax−SELECT *FROM yourTableName WHERE yourColumnName > = DATE_SUB(NOW(), INTERVAL 10 MINUTE);To understand the above syntax, let us create a table. The query to create a table is as follows−mysql> create table users -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserName varchar(20), -> UserLastseen datetime, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.91 sec)Insert some records in the table using insert command. The query is as follows−mysql> insert into users(UserName, UserLastseen) values('Larry', '2019-01-15 02−45−00'); Query ...
Read MoreHow to replace values of select return in MySQL?
You can use select case statement for this. The syntax is as follows.select yourColumnName1, yourColumnName2, ...N, case when yourColumnName=1 then 'true' else 'false' end as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows.mysql> create table selectReturnDemo -> ( -> Id int, -> Name varchar(100), -> isGreaterthan18 tinyint(1) -> ); Query OK, 0 rows affected (0.62 sec)Now you can insert some records in the table using insert command. The query is as follows.mysql> insert into selectReturnDemo values(1, 'Carol', 0); Query OK, 1 row affected (0.23 sec) mysql> ...
Read MoreHow to search for exact string in MySQL?
You can use binary to search for exact string in MySQL. The syntax is as follows:SELECT * FROM yourTableName WHERE BINARY yourColumnName = yourStringValue;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table ExactSearch -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserId varchar(10), -> UserName varchar(20), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command. The query is as follows:mysql> insert into ExactSearch(UserId, UserName) values('USER12', 'John'); Query OK, 1 row ...
Read MoreHow do I show a MySQL warning that just happened?
To show a MySQL warning, you can use the below syntax −SHOW WARNINGS;The above syntax only displays the immediate warning from MySQL prompt. Suppose you run another query between them or you have lost the MySQL connection, then SHOW WARNINGS will not work.Here is the query to display warnings −mysql> SHOW WARNINGS;Here is the output that displays immediate warning −+-------+------+---------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Level | Code | Message ...
Read MoreMySQL SELECT IF statement with OR?
You can use SELECT IF statement with OR. To understand select with OR, let us create a table. The query to create a table is as follows −mysql> create table EmployeeInformation -> ( -> EmployeeId int, -> EmployeeName varchar(100), -> EmployeeStatus varchar(100) -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into EmployeeInformation values(1, 'Sam', 'FullTime'); Query OK, 1 row affected (0.23 sec) mysql> insert into EmployeeInformation values(2, 'Mike', 'PartTime'); Query OK, 1 row affected (0.14 sec) mysql> ...
Read MoreHow to part DATE and TIME from DATETIME in MySQL?
To part DATE and TIME from DATETIME, you can use the DATE_FORMAT() method from MySQL. The syntax is as follows −SELECT DATE_FORMAT(yourColumnName, '%Y-%m-%d') VariableName, DATE_FORMAT(yourColumnName, '%H:%i:%s') VariableName from yourTableName;To understand the above method DATE_FORMAT(), let us create a table with data type “datetime”.Creating a table −mysql> create table DateAndTimePartDemo -> ( -> YourDateandtime datetime -> ); Query OK, 0 rows affected (0.56 sec)Now, I am inserting current date and time using now(). The query is as follows −mysql> insert into DateAndTimePartDemo values(now()); Query OK, 1 row affected (0.37 sec)Display the record ...
Read MoreHow to check for duplicates in MySQL table over multiple columns?
To check for duplicates in MySQL, you can use group by having clause. The syntax is as follows.select yourColumnName1, yourColumnName2, ......N, count(*) as anyVariableName from yourTableName group by yourColumnName1, yourColumnName2 having count(*) > 1;To understand the above syntax, let us create a table. The query to create a table is as follows.mysql> create table DuplicateDemo -> ( -> StudentId int not null, -> StudentFirstName varchar(100), -> StudentLastName varchar(100), -> Primary Key(StudentId) -> ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert command. The query is as follows.mysql> insert into DuplicateDemo values(1, 'John', 'Smith'); Query ...
Read More