Found 6702 Articles for Database

Working with hex numbers in MySQL?

Chandu yadav
Updated on 30-Jun-2020 08:02:12

343 Views

In order to work with hex, use the CONV() function to convert between bases. The syntax is as follows −SET anyVariableName = CONV(yourHexValue, 16, 10);To understand the above syntax, let us create a stored procedure. The query to create a stored procedure is as follows −mysql> DELIMITER // mysql> CREATE PROCEDURE SP_HEX_TO_DEC( HEXVALUE VARCHAR(10) )    -> BEGIN    -> DECLARE Decimalvalue INTEGER;    -> SET Decimalvalue = CONV(HEXVALUE, 16, 10);    -> select Decimalvalue;    -> END;    -> // Query OK, 0 rows affected (0.19 sec) mysql> DELIMITER ;The above stored procedure converts the hexadecimal to decimal. As ... Read More

Create MySQL query to create a table from an existing table?

Ankith Reddy
Updated on 30-Jul-2019 22:30:24

343 Views

You can use CREATE TABLE command to create a table from an existing table. The syntax is as follows:CREATE TABLE yourNewTableName LIKE yourOldTableNameTo understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table ShowCreateTableCommand    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> FirstName varchar(20),    -> LastName varchar(20),    -> Age int,    -> TotalMarks int,    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (1.22 sec)Here is the query to describe a table using DESC command. The query is as follows:mysql> desc ... Read More

How to change collation to utf8_bin in a single line?

Arjun Thakur
Updated on 30-Jul-2019 22:30:24

111 Views

You need to use ALTER command to change collation to utf8_bin. The syntax is as follows:ALTER TABLE yourTableName COLLATE utf8_general_ci;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table CollateDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(20),    -> Age int,    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.98 sec)Check the DDL of the table. The syntax is as follows:SHOW CREATE TABLE yourTableName;Let us now check the DDL of our table:mysql> show create table CollateDemo;The following is ... Read More

How to search for exact string in MySQL?

George John
Updated on 30-Jul-2019 22:30:24

1K+ Views

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 More

MySQL date format to convert dd.mm.yy to YYYY-MM-DD?

Chandu yadav
Updated on 30-Jul-2019 22:30:24

18K+ Views

Use STR_TO_DATE() method from MySQL to convert. The syntax is as follows wherein we are using format specifiers. The format specifiers begin with %.SELECT STR_TO_DATE(yourDateColumnName, '%d.%m.%Y') 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 ConvertIntoDateFormat    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> LoginDate varchar(30),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into ConvertIntoDateFormat(LoginDate) values('11.01.2019'); Query OK, 1 ... Read More

MYSQL: Can you pull results that match like 3 out of 4 expressions?

Arjun Thakur
Updated on 30-Jul-2019 22:30:24

45 Views

You can use CASE statement to get the results that match some expressions−SELECT *FROM yourTableName WHERE CASE WHEN yourColumnName1 = yourValue1 THEN 1 ELSE 0 END +    CASE WHEN yourColumnName2 = yourValue2 THEN 1 ELSE 0 END +    CASE WHEN yourColumnName3 = yourValue3 THEN 1 ELSE 0 END +    .    . CASE WHEN yourColumnNameN = yourValueN THEN 1 ELSE 0 END > = 3;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table UserInformation    -> (    -> Id int NOT NULL AUTO_INCREMENT, ... Read More

How to select all records that are 10 minutes within current timestamp in MySQL?

George John
Updated on 30-Jul-2019 22:30:24

2K+ Views

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 More

Grab where current date and the day before with MySQL?

Chandu yadav
Updated on 30-Jul-2019 22:30:24

2K+ Views

You can grab the current date with CURDATE() and the day before with MySQL using DATE_SUB() with INTERVAL 1 DAY. The syntax is as follows:SELECT DATE_SUB(CURDATE(), INTERVAL 1 DAY);The syntax is as follows to get curdate and the day before with date_sub().SELECT *FROM yourTableName WHERE yourColumnName = CURDATE() OR yourColumnName = DATE_SUB(CURDATE(), INTERVAL 1 DAY);To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table ProductDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> ProductName varchar(20),    -> ProductOfferDate datetime,    -> PRIMARY KEY(Id)    -> ... Read More

How to concat Values in MySQL Query and to handle Null values as well?

Ankith Reddy
Updated on 30-Jul-2019 22:30:24

1K+ Views

You can use CONCAT() method to concatenate values while IFNULL() method is used to handle NULL values. The syntax is as follows:SELECT CONCAT('anyStringValue:', IFNULL(yourColumnName, 'anyStringValue’)) 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 ConcatValues    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> FirstName varchar(20),    -> MiddleName varchar(20),    -> LastName varchar(20),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command. The query is as follows:mysql> insert ... Read More

What is the limit of auto_increment (integer) in MySQL?

Arjun Thakur
Updated on 30-Jul-2019 22:30:24

914 Views

The limit of auto_increment integer depends on column data type. Displayed as follows:The data type TINYINT range is 127 The data type UNSIGNED TINYINT range is 255 The data type SMALLINT range is 32767 The data type UNSIGNED SMALLINT range is 65535 The data type MEDIUMINT range is 8388607 The data type UNSIGNED MEDIUMINT range is 16777215 The data type INT range is 2147483647 The data type UNSIGNED INT range is 4294967295 The data type BIGINT range is 9223372036854775807 The data type UNSIGNED BIGINT range is 18446744073709551615Let us take an example of TINYINT. If you will give beyond 127, then ... Read More

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