AmitDiwan has Published 10740 Articles

Find the count of EMPTY or NULL columns in a MySQL table?

AmitDiwan

AmitDiwan

Updated on 09-Sep-2019 08:10:53

1K+ Views

Let us first create a table −mysql> create table DemoTable781 ( Name varchar(100) ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable781 values(''); Query OK, 1 row affected (0.29 sec) mysql> insert into DemoTable781 values('Chris'); Query ... Read More

How to display the column names from a table excluding some in MySQL?

AmitDiwan

AmitDiwan

Updated on 09-Sep-2019 08:09:06

390 Views

To exclude some of the column names, use NOT IN.Let us first create a table −mysql> create table DemoTable780 (    CustomerId int,    CustomerName varchar(100),    CustomerAge int, CustomerCountryName varchar(100), isMarried tinyint(1) ); Query OK, 0 rows affected (0.47 sec)Here is the query ... Read More

Increment column value ‘ADD’ with MySQL SET clause

AmitDiwan

AmitDiwan

Updated on 09-Sep-2019 08:06:27

230 Views

Since the column value ‘ADD’ is already a reserved word, therefore you need to use backticks around the word ADD like `ADD`.Let us see an example and create a table −mysql> create table DemoTable779 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, `ADD` int ... Read More

Select rows from a MySQL table and display using IN()

AmitDiwan

AmitDiwan

Updated on 09-Sep-2019 08:04:43

263 Views

Let us first create a table −mysql> create table DemoTable778 ( ClientId varchar(100), ClientName varchar(100) ); Query OK, 0 rows affected (1.05 sec)Insert some records in the table using insert command −mysql> insert into DemoTable778 values('J-101', 'John'); Query OK, 1 row affected (0.20 sec) ... Read More

MySQL query to display the column and its values using OR in WHERE statement

AmitDiwan

AmitDiwan

Updated on 09-Sep-2019 08:02:13

106 Views

Let us first create a table −mysql> create table DemoTable777 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(100), StudentAge int ); Query OK, 0 rows affected (1.34 sec)Insert some records in the table using insert command −mysql> insert into ... Read More

Why does the following error occur in MySQL: ERROR 1062 (23000): Duplicate entry?

AmitDiwan

AmitDiwan

Updated on 09-Sep-2019 07:59:17

3K+ Views

Let’s say you have set column values as unique key and try to insert duplicate values in the table. This will lead to ERROR 1062 (23000): Duplicate entry.Let us first create a table -mysql> create table DemoTable776 (    FirstValue int,    SecondValue int,    unique key(FirstValue, SecondValue) ); Query ... Read More

Selecting rows that are older than current date in MySQL?

AmitDiwan

AmitDiwan

Updated on 03-Sep-2019 14:41:53

896 Views

Let’s say the current date is 2019-08-03. Now, we will see an example and create a table −mysql> create table DemoTable840(DueDate datetime); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command −mysql> insert into DemoTable840 values('2019-08-9'); Query OK, 1 row affected (0.10 sec) mysql> ... Read More

MySQL query to sum rows having repeated corresponding Id

AmitDiwan

AmitDiwan

Updated on 03-Sep-2019 14:39:00

276 Views

To sum, you can use aggregate function SUM(). Let us first create a table −mysql> create table DemoTable850(    Id int,    Price int ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable850 values(1, 90); Query OK, 1 row ... Read More

Change the curdate() (current date) format in MySQL

AmitDiwan

AmitDiwan

Updated on 03-Sep-2019 14:23:43

9K+ Views

The current date format is ‘YYYY-mm-dd’. To change current date format, you can use date_format().Let us first display the current date −mysql> select curdate();This will produce the following output −+------------+ | curdate() | +------------+ | 2019-08-08 | +------------+ 1 row in set (0.00 sec)Following is the query to change ... Read More

MySQL query to multiply values of two rows and add the result

AmitDiwan

AmitDiwan

Updated on 03-Sep-2019 14:19:33

1K+ Views

For this, use aggregate function SUM(). Within this method, multiply the row values. Let us first create a table −mysql> create table DemoTable(    ProductQuantity int,    ProductPrice int ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, ... Read More

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