Found 4378 Articles for MySQL

How do I see what a MySQL view is made of?

karthikeya Boyini
Updated on 30-Jun-2020 11:54:49

106 Views

Following is the syntax −show create view yourViewName;Let us first create a table −mysql> create table DemoTable -> ( -> StudentName varchar(20) -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+-------------+ | StudentName | +-------------+ | ... Read More

How do I search and replace specific chars at the beginning of a string in MySQL?

Rama Giri
Updated on 30-Jul-2019 22:30:26

197 Views

For this, you can use INSERT(). Let us first create a table −mysql> create table DemoTable    -> (    -> ZipCode varchar(200)    -> ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('9030'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('3902'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('9083'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values('9089'); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement ... Read More

Finding number of occurrences of a specific string in MySQL?

karthikeya Boyini
Updated on 30-Jun-2020 12:02:21

379 Views

Use LENGTH() for this. Let us first create a table −mysql> create table DemoTable -> ( -> Value text -> ); Query OK, 0 rows affected (0.74 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('10, 20, 10, 30, 10, 40, 50, 40'); Query OK, 1 row affected (0.24 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+-------------------------+ | Value | +-------------------------+ | 10, 20, 10, 30, ... Read More

How to insert auto_increment in an already created table in MySQL?

karthikeya Boyini
Updated on 30-Jun-2020 12:03:12

178 Views

Use ALTER command for this. Let us first create a table −mysql> create table DemoTable -> ( -> StudentName varchar(100) -> ); Query OK, 0 rows affected (0.46 sec)Here is the query to insert auto_increment −mysql> alter table DemoTable ADD COLUMN StudentId int NOT NULL; Query OK, 0 rows affected (0.50 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> alter table DemoTable ADD PRIMARY KEY(StudentId); Query OK, 0 rows affected (1.23 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> alter table DemoTable CHANGE StudentId StudentId int NOT NULL AUTO_INCREMENT; Query OK, 0 rows affected (2.20 sec) Records: 0 ... Read More

Fix Error with TYPE=HEAP for temporary tables in MySQL?

Sharon Christine
Updated on 30-Jun-2020 12:11:41

190 Views

The TYPE=HEAP deprecated in newer MySQL versions. You can use ENGINE=HEAP instead of TYPE. Following is the syntax −ENGINE=HEAP;Let us first create a table. Here, we have set Engine=HEAP −mysql> create TEMPORARY table DemoTable    -> (    -> StudentId int,    -> StudentName varchar(30)    -> )Engine = HEAP; Query OK, 0 rows affected (0.00 sec)Let us check the definition of table −mysql> show create table DemoTable;OutputThis will produce the following output −+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table        | Create Table | +--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | DemoTable | CREATE TEMPORARY TABLE `DemoTable` (`StudentId` int(11) DEFAULT NULL, `StudentName` varchar(30) COLLATE utf8_unicode_ci DEFAULT ... Read More

How to place number 0 from a column at the end maintaining the ascending search order in MySQL?

Sharon Christine
Updated on 30-Jun-2020 12:13:44

67 Views

Let us first create a table −mysql> create table DemoTable    -> (    -> Number int    -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(9); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(4); Query OK, 1 row affected (0.31 sec) mysql> insert into DemoTable values(0); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(7); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(11); Query OK, 1 row affected (0.12 sec)Display all ... Read More

How to order by timestamp in MySQL?

karthikeya Boyini
Updated on 30-Jun-2020 11:28:26

713 Views

To order by timestamp, use the ORDER BY as in the following syntax −select *from yourTableName ORDER BY STR_TO_DATE(`yourColumnName`, '%m/%d/%Y%h:%i:%s %p');Let us first create a table −mysql> create table DemoTable    -> (    -> `timestamp` varchar(100)    -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('06/22/2019 01:10:20 PM'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('06/22/2019 12:00:27 PM'); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values('06/22/2019 06:56:20 AM'); Query OK, 1 row affected (0.23 sec) ... Read More

Add a new column and set values in it on the basis of conditions in MySQL?

karthikeya Boyini
Updated on 30-Jun-2020 11:29:33

3K+ Views

To set values on the basis of conditions, use IF() method. Let us first create a table −mysql> create table DemoTable    -> (    -> Age int    -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(19); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(16); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(17); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(22); Query OK, 1 row affected (0.19 sec)Display all records from ... Read More

Select multiple columns and display in a single column in MySQL?

karthikeya Boyini
Updated on 30-Jun-2020 11:30:41

5K+ Views

Use concat() for this. Let us first create a table −mysql> create table DemoTable    -> (    -> FirstName varchar(30),    -> LastName varchar(30)    -> ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 'Brown'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Adam', 'Smith'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Carol', 'Taylor'); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following ... Read More

Get the difference between dates and calculate salary with MySQL?

karthikeya Boyini
Updated on 30-Jun-2020 11:33:42

303 Views

Let’s say you need to get the difference between dates (JoiningDate – EndDate) of a month i.e. days to calculate the salary. The daily-wage salary is let’s say 300; therefore for 20 days, it will 6000. In the same way, for 27 days, it will be 8100.For our example, let us first create a tablemysql> create table DemoTable    -> (    -> JoinDate date,    -> EndDate date    -> ,    -> Value int    -> ); Query OK, 0 rows affected (1.16 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-01-01', '2019-01-31', ... Read More

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