MySQL query to select top 10 records?

Sharon Christine
Updated on 30-Jun-2020 14:54:57

11K+ Views

To select top 10 records, use LIMIT in MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> PageNumber text -> ); Query OK, 0 rows affected (2.50 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Page-1'); Query OK, 1 row affected (0.46 sec) mysql> insert into DemoTable values('Page-2'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('Page-3'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values('Page-4'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Page-5'); Query OK, ... Read More

How to use peek() in android ConcurrentLinkedDeque?

karthikeya Boyini
Updated on 30-Jun-2020 14:54:52

238 Views

Before getting into the example, we should know what ConcurrentLinkedDeque is, it is unbounded deque based on linked nodes. Multiple threads can access deque elements with safety.This example demonstrates about How to use peek() in android ConcurrentLinkedDequeStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a text view to show ConcurrentLinkedDeque elements.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.os.Build; import android.os.Bundle; ... Read More

Converting table from MyISAM to INNODB in MySQL?

Sharon Christine
Updated on 30-Jun-2020 14:53:21

261 Views

For this, use ALTER command. Let us first create a table. The default engine is set as“MYISAM” −mysql> create table DemoTable -> ( -> ClientId int NOT NULL AUTO_INCREMENT, -> ClientName varchar(100), -> ClientAge int, -> ClientCountryName varchar(100), -> isMarried boolean, -> PRIMARY KEY(ClientId) -> )ENGINE=MyISAM; Query OK, 0 rows affected (0.67 sec)Following is the query to convert table from MyISAM to INNODB −mysql> alter table DemoTable ENGINE=InnoDB; Query OK, 0 rows affected (1.97 sec) Records: 0 Duplicates: 0 Warnings: 0Let us now check the status of table −mysql> show create table DemoTable;OutputThis will produce the following output displaying the ... Read More

Advantage of multiple chip select lines

George John
Updated on 30-Jun-2020 14:53:07

327 Views

Let’s consider that the EPROMs we have are having the starting addresses as 4000H, 4400H, …, 5C00H. 4000H in binary is 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0. In such a case, the 74138 has to be selected for the condition A15 A14 A13 = 0 1 0. This can be achieved by the connection shown in below figure which uses two invert gates.The procedure of selecting the chip74138 is denoted by the addresses A15 A14 A13 = 0 1 0 which can be implemented by any gates. We have taken ... Read More

Can we get records “Jone Deo” or “Deo Jone” with a single MySQL query?

karthikeya Boyini
Updated on 30-Jun-2020 14:52:43

112 Views

For this, you can use the LIKE clause. Let us first create a table −mysql> create table DemoTable    -> (    -> ClientName varchar(100)    -> ); Query OK, 0 rows affected (0.85 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John Smith'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Smith John'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Jone Deo'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Deo Jone'); Query OK, 1 row affected (0.14 sec) mysql> ... Read More

How to add column and index in a single MySQL query?

karthikeya Boyini
Updated on 30-Jun-2020 14:51:51

4K+ Views

Use ALTER for this with ADD. Following is the syntax −alter table yourTableName add yourColumnName DATETIME DEFAULT NOW(), add index(yourColumnName);Let us first create a table −mysql> create table DemoTable    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(100),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.69 sec)Let us check the description of the table −mysql> desc DemoTable;OutputThis will produce the following output −+-------+--------------+------+-----+---------+----------------+ | Field | Type         | Null | Key | Default | Extra          | +-------+--------------+------+-----+---------+----------------+ | Id    | int(11) ... Read More

How to search on a MySQL varchar column using a number?

Sharon Christine
Updated on 30-Jun-2020 14:50:28

370 Views

Use INSERT() function from MySQL. It has the following parameters −ParameterDescriptionstrString to be modifiedpositionPosition where to insert str2numberNumber of characters to replacestr2String to insert into strLet us first create a table −mysql> create table DemoTable    -> (    -> Code varchar(100)    -> ); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('958575/98') ; Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('765432/99'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('983456/91'); Query OK, 1 row affected (0.15 sec)Display all ... Read More

Order by desc except a single value in MySQL

Sharon Christine
Updated on 30-Jun-2020 14:49:46

1K+ Views

Use ORDER BY and set DESC to order by desc. However, to get all the values except a single value, use the not equal operator.Let us first create a table −mysql> create table DemoTable    -> (    -> Name varchar(100)    -> ); Query OK, 0 rows affected (0.89 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Sam'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('John'); Query OK, 1 row affected (0.15 sec) mysql> insert ... Read More

How to use peak() in android LinkedBlockingDeque?

Samual Sam
Updated on 30-Jun-2020 14:46:05

166 Views

Before getting into the example, we should know what LinkedBlockingDeque is. It is implemented by Collection interface and the AbstractQueue class. It provides optional boundaries based on linked nodes. It going to pass memory size to a constructor and helps to provide memory wastage in android.This example demonstrates about How to use peak() in android LinkedBlockingDequeStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a ... Read More

MySQL query to first set negative value in descending order and then positive value in ascending order

karthikeya Boyini
Updated on 30-Jun-2020 14:45:28

558 Views

For this, you can use UNION. Let us first create a table −mysql> create table DemoTable -> ( -> Number int -> ); Query OK, 0 rows affected (1.17 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(-9); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(-190); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(190); Query OK, 1 row affected ... Read More

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