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MySQLi Articles
Page 329 of 341
Can we use IFNULL along with MySQL ORDER BY?
You can use IFNULL along with ORDER BY clause. The syntax is as follows −SELECT *FROM yourTableName ORDER BY IFNULL(yourColumnName1, yourColumnName2);To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table IfNullDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> ProductName varchar(10), -> ProductWholePrice float, -> ProductRetailPrice float, -> PRIMARY KEY(Id) -> ); 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 IfNullDemo(ProductName, ProductWholePrice, ProductRetailPrice) values('Product-1', 99.50, ...
Read MoreMySQL query to group data in the form of user login time per hour and get the records of the users logged in the recent hour?
You can use a subquery with JOIN condition for this. The syntax is as follows −SELECT yourTablevariableName.* FROM ( SELECT MAX(UNIX_TIMESTAMP(yourDateTimeColumnName)) AS anyAliasName FROM getLatestHour GROUP BY HOUR(UserLoginDateTime) ) yourOuterVariableName JOIN yourTableName yourTablevariableName ON UNIX_TIMESTAMP(yourDateTimeColumnName) = yourOuterVariableName.yourAliasName WHERE DATE(yourDateTimeColumnName) = 'yourDateValue';To understand the above syntax and the result to be achieved, let us create a table. The query to create a table is as follows −mysql> create table getLatestHour -> ( -> UserId int, -> UserName varchar(20), -> UserLoginDateTime ...
Read MoreMySQL GROUP BY with WHERE clause and condition count greater than 1?
To understand the group by with where clause, let us create a table. The query to create a table is as follows −mysql> create table GroupByWithWhereClause -> ( -> Id int NOT NULL AUTO_INCREMENT, -> IsDeleted tinyint(1), -> MoneyStatus varchar(20), -> UserId int, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.57 sec)Now you can insert some records in the table using insert command. The query is as follows −mysql> insert into GroupByWithWhereClause(IsDeleted, MoneyStatus, UserId) values(0, 'Undone', 101); Query OK, 1 row affected (0.17 sec) mysql> insert into GroupByWithWhereClause(IsDeleted, MoneyStatus, UserId) ...
Read MoreConvert one base number system to another base system in MySQL
The CONV() function can be used to convert one base number system to another base system.For Example, The 16 is one base system and 10 is another base system. The 16 base system is hexadecimal and 10 is a decimal.The syntax is as follows −SELECT CAST(CONV('yourColumnName', 16, 10) AS UNSIGNED INTEGER) 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 castTypeToBigIntDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Value varchar(100), -> PRIMARY KEY(Id) -> ); Query OK, ...
Read MoreUsing “WHERE binary” in SQL?
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 MoreUsing single quotes around database and table name isn’t working in MySQL?
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 MoreHow to select max of mixed string/int column in MySQL?
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 MoreSelect multiple sums with MySQL query and display them in separate columns?
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 MoreORDER BY alphabet first then follow by number in MySQL?
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 MoreHow to delete last record (on condition) from a table in MySQL?
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 ...
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