Found 6702 Articles for Database

How to set sql_mode permanently in MySQL?

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

801 Views

If you are using Windows Operating System, check your directory my.cnf or my.ini file.mysql> select @@datadir;The following is the output+---------------------------------------------+ | @@datadir | +---------------------------------------------+ | C:\ProgramData\MySQL\MySQL Server 8.0\Data\ | +---------------------------------------------+ 1 row in set (0.00 sec)Reach the above location ‘C:\ProgramData\MySQL\MySQL Server 8.0\Data\”. The screenshot is as follows for my.cnf fileOpen the my.cnf file and write the sql_mode="TRADITIONAL". The syntax is as followssql_mode="TRADITIONAL".After that start your server once again.

Create a procedure in MySQL with parameters?

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

4K+ Views

You can create a parameter using IN and OUT. IN is used to take input parameter and OUT can be used for output.The syntax is as followsDELIMITER // CREATE PROCEDURE yourProcedureName(IN yourParameterName dataType, OUT yourParameterName dataType ) BEGIN yourStatement1; yourStatement2; . . N END; // DELIMITER ;First, we will create a table. The query to create a table is as followsmysql> create table SumOfAll -> ( -> Amount int -> ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command. The query ... Read More

Solve ERROR 1396 (HY000): Operation DROP USER failed for 'user'@'localhost' in MySql?

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

2K+ Views

This error occurs when you drop a user with localhost while you have created a user with ‘%’.Let us create a user with ‘%’ and drop the user as a localhost. The syntax is as followsCREATE USER 'yourUserName'@'%' IDENTIFIED BY 'yourPassword';Let us create a user using the above syntax. The query to create a user is as followsmysql> CREATE USER 'Jack'@'%' IDENTIFIED BY '1234'; Query OK, 0 rows affected (0.26 sec)Check user is created successfully or notmysql> select user, host from MySQL.user;The following is the output+------------------+-----------+ | user             | host      | +------------------+-----------+ ... Read More

Limit length of longtext field in MySQL SELECT results?

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

981 Views

You can use SUBSTRING() from MySQL to limit length of strings. The syntax is as followsSELECT SUBSTRING(yourColumnName, 1, yourIntegerValueToGetTheCharacters) as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table limitLengthOfLongTextDemo -> ( -> sentence LONGTEXT -> ); Query OK, 0 rows affected (0.74 sec)Insert some records in the table using insert command. The query is as followsmysql> insert into limitLengthOfLongTextDemo values('This is the introduction to MySQL'); Query OK, 1 row affected (0.17 sec) mysql> insert into ... Read More

How can a query multiply 2 cells for each row in MySQL?

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

158 Views

You can use multiplication operator (*) between two cells. The syntax is as followsSELECT yourColumnName1, yourColumnName2, yourColumnName1*yourColumnName2 as ‘anyVariableName’ from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table MultiplicationDemo    -> (    -> FirstPrice int,    -> SecondPrice int    -> ); Query OK, 0 rows affected (0.63 sec)Now you can display all records from the table using insert command. The query is as followsmysql> insert into MultiplicationDemo values(10, 2); Query OK, 1 row affected (0.17 sec) mysql> insert into MultiplicationDemo values(4, 2); Query OK, ... Read More

Select last 20 records ordered in ascending order in MySQL?

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

481 Views

To select last 20 records in ascending order, you can use subquery LIMIT clause. The syntax is as followsSELECT *FROM (    SELECT *FROM yourTableName ORDER BY yourColumnName desc limit 20 ) anyVariableName order by anyVariableName.yourColumnName;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table ProductInformation    -> (    -> ProductId int,    -> ProductName varchar(100),    -> ProductPrice int    -> ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert command. The query is as followsmysql> insert into ProductInformation values(101, 'Product-1', ... Read More

How to add a NOT NULL column in MySQL?

Arjun Thakur
Updated on 29-Jun-2020 13:01:56

3K+ Views

You can add a not null column at the time of table creation or you can use it for an existing table.Case 1 − Add a not null column at the time of creating a table. The syntax is as followsCREATE TABLE yourTableName (    yourColumnName1 dataType NOT NULL,    yourColumnName2 dataType    .      .    .    N );The query to create a table is as followsmysql> create table NotNullAtCreationOfTable    -> (    -> Id int not null,    -> Name varchar(100)    -> ); Query OK, 0 rows affected (0.60 sec)In the above table, we ... Read More

Combine INSERT, VALUES, and SELECT in MySQL

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

1K+ Views

You can combine the insert, values and select statement using below syntaxinsert into yourFirstTableName(yourColumnName1, yourColumnName2, .......N) select yourColumnName1, yourColumnName2, .......N from yourSecondTableName where yourCondition;To understand the above syntax, let us create two tables in which first table will get the record from the second table.Let us create the first table without any records. The query to create a table is as followsmysql> create table CombiningInsertValuesSelect    -> (    -> EmployeeId varchar(10),    -> EmployeeName varchar(100),    -> EmployeeAge int    -> ); Query OK, 0 rows affected (6.95 sec)Now you can create the second table with some records. The ... Read More

How to insert DECIMAL into MySQL database?

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

7K+ Views

To insert decimal into MySQL, you can use DECIMAL() function from MySQL. The syntax is as followsyourColumnName DECIMAL(TotalDigit, DigitAfterDecimalPoint);To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table DecimalInsert    -> (    -> Id int,    -> Name varchar(100),    -> Amount DECIMAL(4, 2)    -> ); Query OK, 0 rows affected (0.65 sec)Insert the decimal value using insert command. The query is as followsmysql> insert into DecimalInsert values(1, 'John', 12.4); Query OK, 1 row affected (0.15 sec) mysql> insert into DecimalInsert values(2, 'Carol', 12.34); Query OK, ... Read More

How to declare a variable in MySQL for a normal query?

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

3K+ Views

You can declare a variable using @anyVariablename which is a session variable. To create a session variable, you need to use SET command.The syntax is as followsSET @anyVariableName:=anyValue;You can declare a local variable using DECLARE command. The syntax is as followsDECLARE yourVariableName datatypeYou can set the default value at the time of creating a variable. The syntax is as followsDECLARE yourVariableName datatype default ‘yourValue’Here is the demo of session variable. To understand it, let us create a table.The query to create a table is as followsmysql> create table SessionVariableDemo    -> (    -> EmployeeId varchar(10),    -> EmployeeName varchar(30), ... Read More

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