Found 4218 Articles for MySQLi

Populating a table from query results in MySQL?

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

541 Views

To populate a table from query results, use the following syntax:INSERT yourTableName(yourColumnName1, yourColumnName2, yourColumnName3, ..........N) SELECT yourColumnName1, yourColumnName2, yourColumnName3, ..........N FROM yourAnotherTableName;To understand the above syntax, let us create a table. The first table is as follows with some records. The query to create a table is as follows:mysql> create table PopulateTableDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(20),    -> Amount int,    -> ArrivalDateTime datetime,    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.68 sec)Now you can insert some records in the table using insert command. The ... Read More

How to log in as a different user on MySQL?

George John
Updated on 30-Jun-2020 13:10:49

18K+ Views

If you want to login as a different user on MySQL, you need to use “mysql -u -p command”. The syntax is as follows to login as a different user.>mysql -u yourUsername -p After pressing enter key Enter password −To understand the above syntax, let us create a user in MySQL. The syntax is as follows −CREATE USER 'yourUserName'@'localhost' IDENTIFIED BY 'yourPassword';Now I am going to create a user with name ‘John’ and password is ‘john123456’. The query is as follows −mysql> CREATE USER 'John'@'localhost' IDENTIFIED BY 'john123456'; Query OK, 0 rows affected (0.15 sec)Now check the user has been ... Read More

How to delete last record (on condition) from a table in MySQL?

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

9K+ Views

To delete last record (on condition) from a table, you need to use ORDER BY DESC with LIMIT 1. The syntax is as follows:DELETE FROM yourTableName WHERE yourColumnName1=yourValue ORDER BY yourColumnName2 DESC LIMIT 1;The above syntax will delete last record (on condition) from a table. It sorts the column in descending order and choose the first element to delete.To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table UserLoginTable    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> UserId int,    -> UserLoginDateTime datetime,    -> PRIMARY ... Read More

ORDER BY alphabet first then follow by number in MySQL?

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

971 Views

You need to use regular expression with ORDER BY clause. The syntax is as follows:SELECT *FROM yourTableName ORDER BY IF(yourColumnName RLIKE '^[a-z]', 1, 2), yourColumnName;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table AlphabetFirstThenNumberDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(20),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.95 sec)Insert some records in the table using insert command. The query is as follows:mysql> insert into AlphabetFirstThenNumberDemo(Name) values('John'); Query OK, 1 row affected (0.37 sec) mysql> insert ... Read More

Select multiple sums with MySQL query and display them in separate columns?

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

1K+ Views

To select multiple sum columns with MySQL query and display them in separate columns, you need to use CASE statement. The syntax is as follows:SELECT SUM( CASE WHEN yourColumnName1=’yourValue1’ THEN yourColumnName2 END ) AS yourSeparateColumnName1, SUM( CASE WHEN yourColumnName1=’yourValue2’ THEN yourColumnName2 END ) AS yourSeparateColumnName2, SUM( CASE WHEN yourColumnName1=’yourValue3’ THEN yourColumnName2 END ) AS yourSeparateColumnName3, . . . N FROM yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table selectMultipleSumDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> PlayerName varchar(20),    -> PlayerScore int, ... Read More

How to select max of mixed string/int column in MySQL?

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

291 Views

To select max of mixed string/int column, you need to use substring() function. The syntax is as follows:SELECT MAX(CAST(SUBSTRING(yourColumnName, 4, length(yourColumnName)-3) AS UNSIGNED)) 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 StringIntMixHighestDemo    -> (    -> InvoiceId int NOT NULL AUTO_INCREMENT,    -> InvoiceNumber varchar(20),    -> PRIMARY KEY(InvoiceId)    -> ); Query OK, 0 rows affected (0.65 sec)Now you can insert some records in the table using insert command. The query is as follows:mysql> insert into StringIntMixHighestDemo(InvoiceNumber) values('INV129'); Query OK, 1 row ... Read More

Using single quotes around database and table name isn’t working in MySQL?

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

661 Views

You need to use backticks around table name as well as database name. The syntax is as follows:UPDATE `yourDatabaseName`.`yourTableName` SET yourColumnName1=yourColumnName1+1 WHERE yourColumnName2=’yourValue’;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> use test; Database changed mysql> create table Add1Demo    -> (    -> Id varchar(10),    -> Value int    -> ); Query OK, 0 rows affected (1.19 sec)Insert some records in the table using insert command. The query is as follows:mysql> insert into Add1Demo values('1', 780); Query OK, 1 row affected (0.17 sec) mysql> insert into Add1Demo values('2', ... Read More

How to convert wrongly encoded data to UTF-8 in MySQL?

Samual Sam
Updated on 30-Jul-2019 22:30:24

3K+ Views

You need to use CONVERT() function along with binary keyword. The syntax is as follows −SELECT CONVERT(binary CONVERT(yourColumnName using latin1) USING UTF8) as anyAliasName FROM yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table UtfDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(15),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using INSERT command. The query is as follows −mysql> insert into UtfDemo(Name) values('Obama’s'); Query OK, 1 row affected (0.28 ... Read More

MySQL select distinct rows into a comma delimited list column?

karthikeya Boyini
Updated on 30-Jul-2019 22:30:24

1K+ Views

You can achieve it with the help of GROUP_CONCAT() function. The syntax is as follows −SELECT yourColumnName1, yourColumnName2, yourColumnName3, ..N, GROUP_CONCAT(yourColumnName4) as anyAliasName FROM yourTableName group by yourColumnName3, yourColumnName1, yourColumnName2;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table CommaDelimitedList    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(10),    -> GroupId int,    -> CompanyName varchar(15),    -> RefId int,    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using INSERT command. ... Read More

Using “WHERE binary” in SQL?

karthikeya Boyini
Updated on 30-Jul-2019 22:30:24

3K+ Views

The binary keyword can be used after WHERE clause to compare a value with exact case sensitive match.The following is an example −Case 1 − Case insensitive matchThe query is as follows −mysql> select 'joHN'='JOHN' as Result;The following is the output −+--------+ | Result | +--------+ | 1 | +--------+ 1 row in set (0.00 sec)In the above sample output, the result is true while we know joHN and JOHN are two different words. This is not a case sensitive match.Case 2 − If you want case sensitive match, use the binary keyword.The query is ... Read More

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