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We can check whether a string of specified pattern is not present within another string by using NOT LIKE operator along with wildcard characters.SyntaxNOT LIKE specific_patternSpecific_pattern is the pattern of string we do not want to find out within another string.ExampleSuppose we have a table named ‘student’ having names of the students and we want to get the details of all those students which are not having a pattern of string ‘av’ within their names. It can be done with the help of following MySQL query:mysql> Select * from Student WHERE name NOT LIKE '%av%'; +------+---------+---------+----------+--------------------+ | Id ... Read More
By using mysql dump client program we can take the backup of a particular table from the databases into a file having the extension ‘.sql’. It can be understood with the help of the following example −ExampleIn this example, with the help of mysql dump client program, we are taking the backup of a table named ‘student_info’ from ‘query’ database in a file named ‘student_info.sql’. The following command will do this:C:\mysql\bin>mysqldump -u root query student_info > student_info.sqlThe above command will create a file named student_info.sql which has the dump information of a file named ‘student_info’ from database named ‘query’.Read More
MySQL ORD() function returns the code for the leftmost character if that character is a multi-byte i.e. sequence of one or more bytes, with the help of the following formula(1st bytecode) + (2nd bytecode * 256) + (3rd bytecode * 256^2)On the other hand, ASCII() function returns the ASCII value of the leftmost character of a given string.The difference between them lies on the point that whether the leftmost character is a multi-byte character or not. If it is not a multi-byte character then both ORD() and ASCII() functions return similar results. Following example will demonstrate it.mysql> Select ORD('Tutorialspoint'); +-----------------------+ ... Read More
We need to pass the column name as the argument of OCTET_LENGTH() function to count the number of characters stored in a data column. It displays the number of characters when referenced in SELECT clause. It can also be used as comparison value to decide whether or not the row should returned by using it in WHERE clause. The contents of ‘Student’ table are used to demonstrate it −mysql> Select Name, OCTET_LENGTH(Name)As 'Str_Length' from Student; +---------+------------+ | Name | Str_Length | +---------+------------+ | Gaurav | 6 | | Aarav | 5 ... Read More
By using mysql dump client program we can take the backup of all the databases into a file having the extension ‘.sql’. It can be understood with the help of the following example −ExampleIn this example, with the help of mysql dump client program, we are taking the backup all the databases in a file named ‘alldatabases.sql’. The following command will do this −C:\mysql\bin>mysqldump -u root --all-databases > alldatabases.sqlThe above command will create a file named alldatabases.sql which has the dump information of all the databases.
Suppose if we have dumped the whole database and now want to restore it then we can do it with the following example −C:\mysql\bin>mysql -u root query < tutorials.sqlWith the help of above query, we are restoring the dumped database named ‘tutorials’, in the file tutorials.sql, into other database named ‘query’. It means that the tables of database ‘tutorials’ would be restored in a database named ‘query’.
No, we cannot extend an enum in Java. Java enums can extend java.lang.Enum class implicitly, so enum types cannot extend another class.Syntaxpublic abstract class Enum> implements Comparable, Serializable { // some statements }EnumAn Enum type is a special data type which is added in Java 1.5 version.An Enum is used to define a collection of constants, when we need a predefined list of values which do not represent some kind of numeric or textual data, we can use an enum.Enums are constants and by default, they are static and final. so the names of an enum type fields are in uppercase letters.Public or protected modifiers can only ... Read More
By default MySQL will assume the argument BOTH if the 1st argument is not specified in TRIM() function. Following example will demonstrate it.Examplemysql> SELECT TRIM('A' FROM 'ABCDAEFGAA'); +-----------------------------+ | TRIM('A' FROM 'ABCDAEFGAA') | +-----------------------------+ | BCDAEFG | +-----------------------------+ 1 row in set (0.00 sec)The above result set shows that when we did not specify 1st argument then MySQL returns the output by assuming BOTH as the 1st argument of TRIM() function.
MySQL SUBSTRING() function can be used to extract a substring from a string. Basically SUBSTRING() returns a substring with a given length from a string starting at a specific position. It has various forms as follows −SUBSTRING(str, pos)SUBSTRING(str FROM pos)SUBSTRING(str, pos, len)SUBSTRING(str FROM pos FOR len)The forms without a len argument return a substring from string str starting at position pos. The forms with a len argument return a substring len characters long from string str, starting at position pos. The forms that use FROM are the standard MySQL syntax. It is also possible to use a negative value for ... Read More
We can apply any of the functions like SUBSTRING(), MID() or SUBSTR() to extract a substring from the value of a column. In this case, we must have to provide the name of the column as the first argument of the function i.e. at the place of string we have to give the name of the column. Following example will demonstrate it.ExampleSuppose we want to extract a substring from the ‘Name’ column of ‘Student’ table then it can be done by using the different functions as follows −mysql> Select name, SUBSTR(name, 2, 4) from student; +---------+------------------+ | name | ... Read More