MySQLi Articles

Page 259 of 341

MySQL case-insensitive DISTINCT?

George John
George John
Updated on 30-Jul-2019 5K+ Views

If you want case-insensitive distinct, you need to use UPPER() or LOWER().Case 1: Using UPPER().The syntax is as follows:SELECT DISTINCT UPPER(yourColumnName) FROM yourTableName;Case 2: Using LOWER().The syntax is as follows:SELECT DISTINCT LOWER(yourColumnName) FROM yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table CaseInsensitiveDistinctDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserEmailId varchar(30), -> UserPassword varchar(10), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.64 sec)Now you ...

Read More

Is there a built-in function for week of the month in MySQL?

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jul-2019 937 Views

There is no standard function to get week of month in MySQL. You need to use the following syntax −SELECT WEEK(yourDateColumnName, 5) - WEEK(DATE_SUB(yourDateColumnName, INTERVAL DAYOFMONTH(yourDateColumnName) - 1 DAY), 5) + 1 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 FirstWeekOfMonth -> ( -> Id int NOT NULL AUTO_INCREMENT primary key, -> yourdate date -> ); Query OK, 0 rows affected (2.50 sec)Now you can insert some records in the table ...

Read More

How to add the JDBC MySQL driver to an Eclipse project?

Arjun Thakur
Arjun Thakur
Updated on 30-Jul-2019 12K+ Views

To add the JDBC MySQL driver to an Eclipse project, you need to follow the below steps.The first step is as follows:Step1: Create a dynamic web project with some name in Eclipse.Step2: After pressing the Dynamic Web Project, a new window will open. Now give the project name. The screenshot is as follows:After clicking the Finish button, you will get a project structure. The screenshot is as follows:Therefore, I have a project name JDBCJarFiles and in WEB-INF, there is a lib folder. You can add JDBC jar files in lib folder. Now, paste the jar files here. The screenshot is as ...

Read More

Extracting filenames from a path in MySQL?

Samual Sam
Samual Sam
Updated on 30-Jul-2019 787 Views

To extract filenames from a path MySQL, you can use SUBSTRING_INDEX(). The syntax is as follows −SELECT SUBSTRING_INDEX(ypurColumnName, '', -1) 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 ExtractFileNameDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> AllProgrammingFilePath varchar(100) -> ); Query OK, 0 rows affected (0.50 sec)Now you can insert some records in the table using insert command. The query is as follows −mysql> insert into ExtractFileNameDemo(AllProgrammingFilePath) ...

Read More

Reset MySQL field to default value?

George John
George John
Updated on 30-Jul-2019 2K+ Views

In MySQL, there are two approaches by which you can reset the MySQL field to default value. One is default keyword and another is default() function.Case 1: Using default keyword. The syntax is as follows:UPDATE yourTableName SET yourColumnName=default where yourCondition;Case 2: Using default() function. The syntax is as follows:UPDATE yourTableName SET yourColumnName=default(yourColumnName) where yourCondition;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table Default_Demo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(20),    -> Age int,    -> Salary float,    -> PRIMARY ...

Read More

Change max_heap_table_size value in MySQL?

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jul-2019 2K+ Views

The max_heap_table_size is a system variable that has both read/write property.Initially, max_heap_table_size has size 16 MB. First, check the value of max_heap_table_size, which is in bytes.The query is as follows −mysql> select @@max_heap_table_size;The following is the output −+-----------------------+ | @@max_heap_table_size | +-----------------------+ | 16777216 | +-----------------------+ 1 row in set (0.00 sec)Now let us how the value 16777216 byte = 16 MB −1 MB = 1024KB 1KB = 1024 Bytes 1MB = 1024*1024 bytes. To convert 16777216 byte to MB you need to divide 1024*1024. =16777216/(1024*1024) =16777216/1048576 ...

Read More

Format date in MySQL SELECT * query uisng FORMATDATE() method?

Samual Sam
Samual Sam
Updated on 30-Jul-2019 168 Views

Use the DATE_FORMAT(), not FORMATDATE() in MySQL to format date. The correct syntax is as follows −SE LECT *, DATE_FORMAT(yourDateCoumnName, ’yourFormat’) as anyAliasName FROM yourTableNameTo understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table DateFormatDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> UserName varchar(10),    -> UserLoginDate date    -> ); Query OK, 0 rows affected (0.94 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into DateFormatDemo(UserName, UserLoginDate) values('Mike', curdate()); Query OK, 1 ...

Read More

Sort certain values to the top in MySQL?

Samual Sam
Samual Sam
Updated on 30-Jul-2019 313 Views

You need to use ORDER BY clause to sort. The syntax is as follows −SELECT *FROM yourTableName ORDER BY yourColumnName='yourValue' DESC, yourIdColumnName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table SortCertainValues    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(20),    -> CountryName varchar(10),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (1.36 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into SortCertainValues(Name, CountryName) values('Adam', 'US'); Query OK, 1 row ...

Read More

Insert default into not null column if value is null in MySQL?

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jul-2019 2K+ Views

You can use IFNULL() property or simple IF() with IS NULL property. The syntax is as follows −INSERT INTO yourTableName(yourColumnName1, yourColumnName2) VALUES('yourValue’', IF(yourColumnName1 IS NULL, DEFAULT(yourColumnName2), 'yourMessage'));To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table Post -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> UserName varchar(10), -> UserPostMessage varchar(50) NOT NULL DEFAULT 'Hi Good Morning !!!' -> ); Query OK, 0 rows affected (0.67 sec)Now you can ...

Read More

MySQL Order By date column and integer column, but specify ordering rules of integer column? Is it possible?

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jul-2019 251 Views

You can achieve this with the help of ORDER BY CASE statement. The syntax is as follows −SELECT *FROM yourTableName ORDER BY CASE yourIntegerColumnName1 WHEN 2 THEN 1 ELSE 0 END DESC ,yourDateColumnName ASC;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table OrderByCaseDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> GroupId int,    -> ArrivalDate date,    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (1.57 sec)Insert some records in the table using insert command. The query is as ...

Read More
Showing 2581–2590 of 3,404 articles
« Prev 1 257 258 259 260 261 341 Next »
Advertisements