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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to display the count from distinct records in the same row with MySQL?
For this, you can use GROUP_CONCAT(), COUNT() along with GROUP BY clause. Let us first create a table −mysql> create table DemoTable -> ( -> CompanyId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> CompanyName varchar(20) -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(CompanyName) values('Amazon'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(CompanyName) values('Google'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable(CompanyName) values('Google'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(CompanyName) values('Microsoft'); Query OK, 1 ...
Read MoreFetch info with MySQL EXPLAIN KEYWORD?
Let us first create a table −mysql> create table DemoTable1541 -> ( -> EmployeeId int, -> EmployeeFirstName varchar(20) NOT NULL -> ); Query OK, 0 rows affected (0.94 sec)Here is the query to create an index on the column −mysql> create index emp_name_index on DemoTable1541(EmployeeFirstName); Query OK, 0 rows affected (0.75 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the table using insert command −mysql> insert into DemoTable1541 values(1, 'Robert'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable1541 values(2, 'Adam'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable1541 ...
Read MoreHow to cast and update a numeric value from string column only where applicable in MySQL?
You can use the CEIL() function from MySQL. Let us first create a table. Here, we have taken the first column as VARCHAR −mysql> create table DemoTable -> ( -> Value varchar(20), -> UpdateValue int -> ); Query OK, 0 rows affected (1.08 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value) values('100'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(Value) values('false'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Value) values('true'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(Value) values('1'); Query OK, 1 ...
Read MoreMySQL query to remove string from a column with values EMP1, EMP2, EMP3, etc.
To remove string from the values EMO1, EMP2, etc., you need to use RIGHT() along with LENGTH(). Let us first create a table −mysql> create table DemoTable1540 -> ( -> EmployeeCode varchar(20) -> ); Query OK, 0 rows affected (0.39 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1540 values('EMP9'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1540 values('EMP4'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1540 values('EMP8'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable1540 values('EMP6'); Query OK, 1 row affected (0.12 sec)Display ...
Read MoreMySQL DATE function to return the difference between current date and joining date
At first, find the current date and get the difference between joining date and current date using the DATEDIFF().The current date is as follows −mysql> select curdate(); +------------+ | curdate() | +------------+ | 2019-10-26 | +------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable -> ( -> JoiningDate varchar(40) -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('10/10/1998'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('31/12/2010'); Query OK, 1 row affected (0.09 sec) ...
Read MoreCombine columns into rows with MySQL?
To combine columns into rows, use UNION ALL. Following is the syntax −Syntaxselect yourColumnName1 from yourTableName union all select yourColumnName2 from yourTableName;Let us first create a table −mysql> create table DemoTable -> ( -> Value1 int, -> Value2 int -> ); Query OK, 0 rows affected (0.88 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 200); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(500, 600); Query OK, 1 row affected (0.18 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will ...
Read MoreShould I use a loop or 'OR' operator to query a bunch of stuff at a fast pace In MYSQL?
For faster querying, you need to use MySQL IN(). Let us first create a table −mysql> create table DemoTable1538 -> ( -> ClientId int, -> ClientName varchar(20) -> ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1538 values(101, 'Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable1538 values(102, 'Robert'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable1538 values(103, 'Bob'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1538 values(104, 'Adam'); Query OK, 1 row affected (0.16 sec)Display ...
Read MoreHow to create a column of months from date and display sum of the corresponding column wherein you find duplicate dates?
For this can use DATE_FORMAT() in MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> PurchaseDate date, -> Amount int -> ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-10-12', 500); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('2018-10-12', 1000); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('2019-01-10', 600); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('2018-10-12', 600); Query OK, 1 row affected (0.15 sec) mysql> insert ...
Read MoreHow to write a single MySQL query for displaying a value for multiple inputs?
For this, use BETWEEN keyword. Let us first create a table −mysql> create table DemoTable1537 -> ( -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(20) -> ); Query OK, 0 rows affected (0.72 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1537(StudentName) values('Chris'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1537(StudentName) values('Bob'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable1537(StudentName) values('Sam'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1537(StudentName) values('Mike'); Query OK, 1 row affected (0.16 sec) mysql> insert into ...
Read MoreUsing Update statement with TINYINT in MySQL?
Let us first create a table. We have set one of the columns with type TINYINT −mysql> create table DemoTable -> ( -> EmployeeId int, -> isMarried tinyint -> ); Query OK, 0 rows affected (6.84 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(101, true); Query OK, 1 row affected (1.94 sec) mysql> insert into DemoTable values(102, false); Query OK, 1 row affected (0.76 sec) mysql> insert into DemoTable values(103, true); Query OK, 1 row affected (1.14 sec) mysql> insert into DemoTable values(104, true); Query OK, 1 row affected (1.22 ...
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