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Articles by AmitDiwan
Page 816 of 840
Why does the following error occur in MySQL: ERROR 1062 (23000): Duplicate entry?
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 OK, 0 rows affected (0.74 sec)Insert some records in the table using insert command. While inserting duplicate value, the same error arises as shown below -mysql> insert into DemoTable776 values(10, 20); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable776 values(10, 40); Query OK, 1 row affected (0.15 ...
Read MoreSelecting rows that are older than current date in MySQL?
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> insert into DemoTable840 values('2019-07-5'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable840 values('2019-08-10'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable840 values('2019-07-13'); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement −mysql> select *from DemoTable840;This will produce the ...
Read MoreMySQL query to sum rows having repeated corresponding Id
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 affected (0.15 sec) mysql> insert into DemoTable850 values(2, 100); Query OK, 1 row affected (0.55 sec) mysql> insert into DemoTable850 values(2, 50); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable850 values(1, 80); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable850 values(1, 60); Query OK, ...
Read MoreChange the curdate() (current date) format in MySQL
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 curdate() (current date) format −mysql> select date_format(curdate(), '%m/%d/%Y');This will produce the following output −+------------------------------------+ | date_format(curdate(), '%m/%d/%Y') | +------------------------------------+ | 08/08/2019 | +------------------------------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable ...
Read MoreGet the sum of columns for duplicate records in MySQL
For this, use GROUP BY clause along with aggregate function SUM(). Let us first create a table −mysql> create table DemoTable( Name varchar(100), Score int ); Query OK, 0 rows affected (0.70 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Adam', 50); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Bob', 80); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Adam', 70); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Adam', 10); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Carol', ...
Read MoreDisplay the sum of positive and negative values from a column in separate columns with MySQL
For this, you can use CASE statement. Let us first create a table −mysql> create table DemoTable( Id int, Value int ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, 100); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(10, -110); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(10, 200); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(10, -678); Query OK, 1 row affected (0.17 sec)Display all records from the table using select statement −mysql> ...
Read MoreMySQL query to insert row with date?
Let us first create a table −mysql> create table DemoTable( EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, EmployeeName varchar(100), JoiningDate date ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(EmployeeName, JoiningDate) values('Chris', '2019-01-21'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(EmployeeName, JoiningDate) values('Robert', '2016-12-01'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(EmployeeName, JoiningDate) values('Mike', '2015-03-12'); 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 following output −+------------+--------------+-------------+ ...
Read MoreInserting data into a new column of an already existing table in MySQL?
Let us first create a table −mysql> create table DemoTable( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Name varchar(100) ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name) values('John'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Name) values('Bob'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Name) values('Adam'); Query OK, 1 row affected (0.28 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+----+------+ | Id | Name | +----+------+ | 1 | ...
Read MoreWhat is "SELECT TRUE" in MySQL?
The statement SELECT TRUE returns 1 if a row match. Let us first create a table −mysql> create table DemoTable(Name varchar(100)); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('David'); 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 following output −+--------+ | Name | +--------+ | Chris | | Robert ...
Read MoreHow to display coming Sunday's date for all the date records in MySQL?
Let us first create a table −mysql> create table DemoTable(GetSundayDate date); Query OK, 0 rows affected (0.44 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-08-07'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('2018-09-05'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('2019-09-12'); Query OK, 1 row affected (0.17 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+---------------+ | GetSundayDate | +---------------+ | 2019-08-07 | | 2018-09-05 | | 2019-09-12 | +---------------+ 3 rows in ...
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