Found 4219 Articles for MySQLi

Set auto increment initial value for MySQL table using ALTER command

Chandu yadav
Updated on 30-Jul-2019 22:30:25

557 Views

To set auto increment initial value for MySQL table, use ALTER command. The first step would bealter table yourTableName modify yourColumnName int NOT NULL AUTO_INCREMENT PRIMARY KEY, add index(yourColumnName);The second step is as followsalter table yourTableName AUTO_INCREMENT=yourStartingValue;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table setAutoIncrementDemo    -> (    -> UserId int,    -> UserName varchar(20)    -> ); Query OK, 0 rows affected (0.75 sec)Now implement the above two steps to set auto increment initial value for MySQL table.Step 1 -The query is as followsmysql> alter ... Read More

How to add +1 to existing MySQL values?

Arjun Thakur
Updated on 30-Jul-2019 22:30:25

581 Views

Let us see an example and create a table first.mysql> create table Add1ToExistingValue    -> (    -> Value int    -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into Add1ToExistingValue values(10); Query OK,  1 row affected (0.12 sec) mysql> insert into Add1ToExistingValue values(13); Query OK,  1 row affected (0.15 sec) mysql> insert into Add1ToExistingValue values(15); Query OK,  1 row affected (0.13 sec) mysql> insert into Add1ToExistingValue values(16); Query OK,  1 row affected (0.14 sec) mysql> insert into Add1ToExistingValue values(20); Query OK,  1 row affected (0.16 sec) mysql> insert into Add1ToExistingValue values(40); Query OK,  1 row affected (0.15 sec) mysql> insert into Add1ToExistingValue values(50); Query OK,  1 row affected (0.11 sec) mysql> insert into Add1ToExistingValue values(55); Query OK,  1 row affected (0.17 sec) mysql> insert into Add1ToExistingValue values(56); Query OK,  1 row affected (0.17 sec)Display all records from the table using select statement.The query is as followsmysql> select *from Add1ToExistingValue;The following is the output+-------+ | Value | +-------+ | 10   ... Read More

Resolve the error Column count doesn’t match value count in MySQL?

Ankith Reddy
Updated on 30-Jul-2019 22:30:25

640 Views

This type of error occurs when number of columns does not match whenever you are inserting records in the destination table. For a demo example, let us create a tablemysql> create table errorDemo    -> (    -> User_Id int NOT NULL AUTO_INCREMENT,    -> User_Name varchar(20),    -> PRIMARY KEY(User_Id)    -> ); Query OK, 0 rows affected (0.47 sec)The error is as followsmysql> insert into errorDemo values('John'); ERROR 1136 (21S01): Column count doesn't match value count at row 1To avoid this type of error, you need to use the following syntaxinsert into yourTableName(yourColumnName1, yourColumnName2, ...N)values(yourValue1, yourValue2, ....N);Insert some ... Read More

How to revert rows to default column value in MySQL?

George John
Updated on 30-Jul-2019 22:30:25

149 Views

To revert rows to default column value, let us first create a demo tablemysql> create table defaultDemo    -> (    -> Id int    -> ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into defaultDemo values(10); Query OK, 1 row affected (0.25 sec) mysql> insert into defaultDemo values(20); Query OK, 1 row affected (0.13 sec) mysql> insert into defaultDemo values(30); Query OK, 1 row affected (0.14 sec) mysql> insert into defaultDemo values(40); Query OK, 1 row affected (0.11 sec) mysql> insert into defaultDemo values(80); Query OK, ... Read More

How to convert positive value to negative while inserting in MySQL?

Chandu yadav
Updated on 30-Jul-2019 22:30:25

1K+ Views

Let us first create a tablemysql> create table recordsDemo    -> (    -> UserId int,    -> Value int    -> ); Query OK, 0 rows affected (0.52 sec)Now insert some records in the table using insert command.The query is as followsmysql> insert into recordsDemo values(1, 10); Query OK, 1 row affected (0.17 sec) mysql> insert into recordsDemo values(3, 598); Query OK, 1 row affected (0.18 sec) mysql> insert into recordsDemo values(5, 786); Query OK, 1 row affected (0.25 sec) mysql> insert into recordsDemo values(7, 189); Query OK, 1 row affected (0.16 sec) mysql> insert into recordsDemo values(9, 345); ... Read More

How to loop thrugh a stored procedure in MySQL?

Arjun Thakur
Updated on 30-Jul-2019 22:30:25

178 Views

Let us see how to loop through a stored procedure in MySQLmysql> DELIMITER // mysql> CREATE PROCEDURE do_WhileDemo(LastValue INT)    -> BEGIN       -> SET @loop = 0;       -> REPEAT          -> SET @loop= @loop+ 1;          -> select @loop;          -> UNTIL @loop >LastValue       -> END REPEAT;    -> END // Query OK, 0 rows affected (0.17 sec) mysql> DELIMITER ;Now call the stored procedure with the help of CALL command.The query is as followsmysql> call do_WhileDemo(10);The following is the output+-------+ | ... Read More

Selecting Random Result from MySQL?

Chandu yadav
Updated on 30-Jul-2019 22:30:25

100 Views

You need to use rand() function to select random result from MySQL.The syntax is as followsselect *from yourTableName order by rand() limit 1;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table selectRandomRecord    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(20)    -> ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into selectRandomRecord(StudentName) values('John'); Query OK, 1 row affected (0.17 sec) mysql> insert into selectRandomRecord(StudentName) values('Carol'); Query OK, ... Read More

Stored procedure using variable in LIMIT expression?

George John
Updated on 30-Jul-2019 22:30:25

83 Views

Let us firs create a tablemysql> create table LimitWithStoredProcedure    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(10)    -> ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into LimitWithStoredProcedure(Name) values('John'); Query OK, 1 row affected (0.15 sec) mysql> insert into LimitWithStoredProcedure(Name) values('Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into LimitWithStoredProcedure(Name) values('Maxwell'); Query OK, 1 row affected (0.28 sec) mysql> insert into LimitWithStoredProcedure(Name) values('Bob'); Query OK, 1 row affected (0.24 sec) mysql> insert into LimitWithStoredProcedure(Name) values('David'); Query ... Read More

MySQL UPDATE query where id is highest AND field is equal to variable?

Chandu yadav
Updated on 30-Jul-2019 22:30:25

464 Views

The syntax is as followsupdate yourTableName set yourColumnName1=yourValue where yourColumnName2=yourValue order by yourIdColumnName DESC LIMIT 1;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table UpdateWithHighestDemo    -> (    -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> UserStatus tinyint,    -> UserRank int    -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into UpdateWithHighestDemo(UserStatus, UserRank) values(1, 78); Query OK, 1 row affected (0.12 sec) mysql> insert into UpdateWithHighestDemo(UserStatus, UserRank) values(0, 118); Query ... Read More

How to format number with “.” as thousand separators, and “,” as decimal separator?

Arjun Thakur
Updated on 30-Jul-2019 22:30:25

975 Views

You can use format() function for the separators. It will work in MySQL version greater than or equal to 5.5. We are using the version 8.0.12mysql> select version(); +-----------+ | version() | +-----------+ | 8.0.12 | +-----------+ 1 row in set (0.00 sec)The syntax is as followsSELECT FORMAT(yourColumnName, valueAfterDecimalPoint, 'de_DE') AS anyAliasNamefrom yourTableName;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table formatNumberDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Number DECIMAL(19, 1) ... Read More

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