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Articles on Trending Technologies
Technical articles with clear explanations and examples
Total number of fields in all tables in database?
To get total number of fields in all tables in database, you can use information_schema.columns along with aggregate function count(*).We are using ‘sample’ database which consists of a lot of tables with fields. Following is the query to get total number of fields in all tables in database:mysql> SELECT COUNT(*) AS TOTAL_NUMBER_OF_FIELDS -> FROM INFORMATION_SCHEMA.COLUMNS -> WHERE TABLE_SCHEMA = 'sample';This will produce the following output+------------------------+ | TOTAL_NUMBER_OF_FIELDS | +------------------------+ | 796 | +------------------------+ 1 row in set (0.04 sec)Now, let us check another database ‘test’. Following is the query ...
Read MoreHow do I discover the Quarter of a given Date in Java?
Let us first get the current date −LocalDate currentDate = LocalDate.now();Now, use the Calendar class and set the locale −Calendar cal = Calendar.getInstance(Locale.US);Now, get the month −int month = cal.get(Calendar.MONTH);Find the Quarter −int quarter = (month / 3) + 1;Exampleimport java.time.LocalDate; import java.util.Calendar; import java.util.Locale; public class Demo { public static void main(String[] args) { LocalDate currentDate = LocalDate.now(); System.out.println("Current Date = "+currentDate); Calendar cal = Calendar.getInstance(Locale.US); int month = cal.get(Calendar.MONTH); int quarter = (month / 3) + 1; System.out.println("Quarter = "+quarter); } }OutputCurrent Date = 2019-04-12 Quarter = 2
Read MoreChange max_heap_table_size value in MySQL?
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 MoreGeneration of triangular wave using DAC interface
We write an 8085 assembly language program for the generation of triangular waveform using the Digital to Analog Converter (DAC) interface. The display of the waveform is seen on the CRO.Let us consider a problem solution in this domain. The problem states that: To get unipolar output, J1 is shorted to J2 on the interface. To display the waveform on a CRO, connect pin 1 of connector P1 to CRO signal pin, and pin 2 of connector P1 to CRO ground pin.Program; FILE NAME DAC_TO_TRIANG.ASM ORG C100H X DW 00FFH ; the fall of rise and time I proportional directly to ...
Read MoreHow to add header item for Listview in Android?
This example demonstrates How to add header item for Listview in Android.Step 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 the name and record number as Edit text, when the user clicks on the save button it will store the data into ArrayList. Click on ...
Read MoreDoes SELECT TOP command exist in MySQL to select limited number of records?
There is no concept of TOP in MySQL. The alternate way to write your query is using LIMIT i.e to select 2 records, you need to use TOP 2. Let us see the syntax for the same in MySQLSELECT *FROM yourTableName ORDER BY yourColumnName DESC LIMIT 2;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table Top2Demo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > Name varchar(20), - > Age int - > ); Query OK, 0 rows ...
Read MoreHow to parse json string in android?
This example demonstrates How to parse JSON string in android.Step 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 the json element name.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.app.KeyguardManager; import android.app.admin.DevicePolicyManager; import android.content.Context; import android.net.ConnectivityManager; import android.net.Network; import android.net.NetworkInfo; import android.os.Build; import android.os.Bundle; import android.os.Environment; import android.support.annotation.RequiresApi; import android.support.v7.app.AppCompatActivity; import android.view.KeyEvent; import android.widget.TextView; import ...
Read MoreHow to change a primary key in MySQL to auto_increment?
To change a primary key to auto_increment, you can use MODIFY command. Let us first create a table.mysql> create table changePrimaryKeyInAutoIncrement -> ( -> StudentId int not null primary key, -> StudentName varchar(100), -> StudentAge int, -> StudentAddress varchar(100) -> ); Query OK, 0 rows affected (0.63 sec)Let us now check the description of table using desc command:mysql> desc changePrimaryKeyInAutoIncrement;This will produce the following output+----------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------------+--------------+------+-----+---------+-------+ | StudentId | int(11) ...
Read MoreHow to get number of quarters between two dates in Java
Let’s say we have the following two dates −LocalDate.of(2019, 3, 20); LocalDate.of(2019, 10, 25);To get the number of quarters between the above two dates, use the QUARTER_YEARS −IsoFields.QUARTER_YEARS.between(LocalDate.of(2019, 3, 20),LocalDate.of(2019, 10, 25));Exampleimport java.time.LocalDate; import java.time.temporal.IsoFields; public class Demo { public static void main(String[] args) { long quarters = IsoFields.QUARTER_YEARS.between(LocalDate.of(2019, 3, 20), LocalDate.of(2019, 10, 25)); System.out.println("Quarters between the two dates = " + quarters); } }OutputQuarters between the two dates = 2
Read MoreWhat reasons could make your training a flop?
You have attended a great training session, which was very interactive and all the participants enjoyed the session. Even the trainer was very good, but still, there was not a great outcome from it. What could be the reason?It may be because Service / Customer Satisfaction Scores Are Poor. In other words, you might not have scheduled enough employees to handle responsibilities, like the lunchtime rush, or the cashier stations, or parking during a busy holiday week. There could be many other reasons too:Irrelevant Topics Discussed: We need to evaluate the training properly. Maybe the topic of the training was not ...
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