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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to use special characters in column names with MySQL?
Using backticks around the column name will allow you to use special characters. Let us first create a table −mysql> create table DemoTable -> ( -> `Student-Id` int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> `Student-Name` varchar(100), -> `Student-Age` int -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Chris', 21); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Mike', 19); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable(`Student-Name`, `Student-Age`) values('Bob', 18); Query OK, ...
Read MoreFetch middle part of a string surrounded by slash in MySQL
Let us first create a table −mysql> create table DemoTable -> ( -> Code varchar(100) -> ); Query OK, 0 rows affected (1.07 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('/101/102/106'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('/110/111/101'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('/111/114/201'); Query OK, 1 row affected (0.47 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+--------------+ | Code | +--------------+ | ...
Read MoreCan we use semicolon as a MySQL DEMILITER?
No, we cannot. If you still did it, then stored procedure won’t get created. Therefore, first you need to change your DELIMITER from semicolon(;) to others like (// ,??..etc). Following is the syntax −DELIMITER // CREATE PROCEDURE yourProcedureName() BEGIN yourStatement1, . . . . N END // DELIMITER ;Let us implement the above syntax in order to create a stored procedure −mysql> DELIMITER // mysql> CREATE PROCEDURE get_Message() -> BEGIN -> SELECT CONCAT("HELLO", " ", "MYSQL USERS"); -> END -> // Query OK, 0 rows affected (0.23 sec) mysql> DELIMITER ;Now you can call the stored ...
Read MoreCan we use PRIMARY KEY( column1, column2) in MySQL to make pairs?
Yes, you can use below syntax. Following is the syntax −PRIMARY KEY(yourColumnName1, yourColumnName2);Let us first create a table −mysql> create table DemoTable -> ( -> StudentFirstName varchar(100), -> StudentLastName varchar(100), -> StudentAge int, -> StudentCountryName varchar(100), -> PRIMARY KEY(StudentFirstName, StudentLastName) -> ); Query OK, 0 rows affected (0.74 sec)Let us check the description of the table −mysql> desc DemoTable;OutputThis will produce the following output −+--------------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------------------+--------------+------+-----+---------+-------+ | StudentFirstName | ...
Read MoreImplement multiple COUNT() in a single MySQL query
For this, use CASE statement. Let us first create a table −mysql> create table DemoTable -> ( -> LastName varchar(100) -> ); Query OK, 0 rows affected (0.60 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Brown'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Brown'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Smith'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Taylor'); Query OK, 1 ...
Read MoreHow to exclude a specific row from a table in MySQL?
Use i.e. not equal in MySQL to exclude a specific row from a table. Let us first create a table −mysql> create table DemoTable -> ( -> Id int, -> FirstName varchar(100) -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(1, 'John'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(2, 'Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(3, 'Robert'); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable ...
Read MoreHow to add multiple intervals to DATE_ADD() in MySQL?
The current date and time is as follows −mysql> select now();OutputThis will produce the following output −+---------------------+ | now() | +---------------------+ | 2019-06-15 12:24:06 | +---------------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable ->( -> ArrivalDate datetime -> ); Query OK, 0 rows affected (1.15 sec)Insert some records in the table using insert command. Here, we are adding multiple intervals to the DATE_ADD() method −mysql> insert into DemoTable values(DATE_ADD(DATE_ADD(NOW(), INTERVAL 6 MONTH), INTERVAL 1 YEAR)); Query OK, 1 row affected (0.13 sec) ...
Read MoreWhat are the drinks that help recover from morning hangover?
Water is a miraculous drink, not only to recover from the morning hangover but otherwise also. Drink loads of water. It will flush out all the toxins and keep you fresh.Coconut Water − Why to go for artificial flavored foods and drinks? Coconut water is a boon for many, especially to recover from a hangover.Tomato Juice − A glass of tomato juice packs enough simple sugars to get your levels up, and its inflammation-fighting lycopene and serious hydrating factor are beneficial too.Ginger Tea − This is the easiest to fetch and probably the most liked by all. Ginger has many ...
Read MoreWhat are the difference ways to replace nulls values in MySQL using SELECT statement?
There are lots of options available to replace NULL values using select statement. You can use CASE statement or IFNULL() or COALESCE()Case 1 − Using IFNULL()The syntax of IFNULL() is as follows −SELECT IFNULL(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 2 − Using COALESCE()The syntax of COALESCE() is as follows −SELECT COALESCE(yourColumnName, ’yourValue’) AS anyVariableName from yourTableName;Case 3 − Using CASE statementThe syntax of CASE statement.SELECT CASE WHEN yourColumnName IS NULL THEN ‘yourValue’ ELSE yourColumnName END AS anyVariableName FROM yourTableNameTo understand what we discussed above, let us create a table. The query to create a table is as follows −mysql> create ...
Read MoreUpdate an entire row in MySQL?
To update an entire row in MySQL, use UPDATE command. You need to know the primary key column. The syntax is as follows to update an entire row.UPDATE yourTableName SET yourColumnName1 = ’yourValue1’ ,yourColumnName2 = ’yourValue2’ , yourColumnName3 = ’yourValue3’ ,.......................N WHERE yourPrimaryKeyColumnName = yourValue;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table UpdateEntireRowDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Name varchar(20), -> Age int, -> Marks int, -> PRIMARY KEY(Id) -> ); Query OK, ...
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