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Database Programming
Databases are collections of tables that maintain and display information, often collaboratively; this information can be used for interaction with an application or gaining general knowledge. Questions about database engines and modifying or using them belong in this category.
8,803 Questions
What are the advantages and disadvantages of drainage system?
Advantages of Drainage
There is no doubt that a drainage system will improve your crop yield. The implementation of a corrugated polyethylene pipe drainage system gives you more control over the moisture content of the soil than was ever thought possible. With Global Positioning Systems (GPS) not only can you check the overall condition of the soil, you can see how yielding patterns improve when moisture content is altered with a drainage system. Installing a drainage system has a number of impressive benefits. Control over the moisture content of the soil:
- Reduces the effect of droughts and excessive water from heavy rains or snow.
- Increases the temperature of the soil which loses its heat to excessive surface water.
- Improves aeration and the nitrogen content of the soil which results in earlier germination and better root development.
- Eliminates planting delays resulting in a longer growing season
- Removes toxic material and disease organisms
- Reduces soil erosion by creating better root systems
Greater Profitability
If you're looking for better productivity and a faster return on your investment, installing a tile drainage system comes out ahead of new machinery, land acquisition and new buildings. And it does it, convincingly. The profitability begins right from your first crop after installing drains.
Greater Productivity
According to Ontario's Crop Insurance Program, tile-drained farms increase yields from 22% to 42% compared to untiled land.
Improved Conditions for Earlier Planting and Extended Harvest Season
Abruce Tile drainage system will ensure you can be on the field for planting at the earliest possible date. Those wet fall days should not stop you from getting your crops off the fields.
Better Soil Moisture Conditions
With better soil moisture conditions, you can plant your whole field earlier and extend your harvest season. Why? Tile drainage reduces excess moisture where plants take root, encouraging deeper rooting.
Reduced Compaction
Improved soil conditions reduce compacting from fieldwork or harvest operations. A better air/moisture balance in the soil also contributes to better root growth and micro-organic health.
Drought Resistance
And with a properly drained field, your crops are more resistant to drought, because deeper roots are able to find and utilize moisture more efficiently.
Better Use of Inputs
Fertilizer is used more effectively on drained soils. A seedbed that has consistent and ideal moisture speeds germination and emergence. Herbicides applied to the soil adhere better to soil particles.
Energy Saver
Well-drained fields will also take less of your time and energy. You won't have to return to wet areas after they've dried out because you'll have uniform moisture across all of your tiled land.
Increased Land Value
One additional and compelling benefit of a tile drainage system? It's an assured way of increasing the value of your land whether you work the farm yourself or decide to sell.
ddl stands for Data Definaton Language.Eg:- Create ,Alter .Drop.Truncate
Why we have called it as DDL means.... we are defining or acting at structure level. Say, when ever you create a table we are dealing at strucutre level. Hence its is DDL
A char is a time, a turn or an occasion, an odd job, or a woman employed to do housework.
Yes, there would be thousands of databases in both North Korea and South Korea.
compromises that include denormalization
Which computing technology sse1 sse2 sse3 or sse4 better supports data-mining applications?
Which computing technology (SSE1 SSE2 SEE3 or SSE4) better supports data-mining applications
A view of an object (actual or imagined) as it would be seen by an observer who looks at the object either in a chosen direction or from a selected point of view. Pictorial sketches often are more readily made and more clearly understood than are front, top, and side views of an object. Pictorial drawings, either sketched http://www.answers.com/topic/freehand or made with drawing instruments, are frequently used by engineers and architects to convey ideas to their assistants and clients. See alsohttp://www.answers.com/topic/geometry; http://www.answers.com/topic/engineering-drawing. In making a pictorial drawing, the viewing direction that shows the object and its details to the best advantage is chosen. The resultant drawing is http://www.answers.com/topic/orthographic if the viewing rays are considered as parallel, or perspective if the rays are considered as meeting at the eye of the observer. Perspective drawings provide the most realistic, and usually the most pleasing, likeness when compared with other types of pictorial views. Several types of nonperspective pictorial views can be sketched, or drawn with instruments. In the http://www.answers.com/topic/isometric pictorial, the direction of its axes and all measurements along these axes are made with one scale (Fig. 1). Oblique pictorial drawings, while not true orthographic views, offer a convenient method for drawing circles and other curves in their true shape (Fig. 2).
Isometric drawing; measurements along each axis are made with the same scale.
Oblique pictorial drawing. In order to reduce the http://www.answers.com/topic/distortion in an http://www.answers.com/topic/oblique drawing, measurements along the receding axis may be foreshortened. When they are halved, the method is called cabinet drawing.
What are the roles of statistics in management?
Statistics is a useful tool for the leadership ( Managers, Vice Presidents, CEO , Owner of any business etc ) to make decisions.
Example
Organizations made a bar chart to see on what weekdays their employees take maximum leaves. They found that most the employees took these unscheduled leaves on a Friday or Monday or both.
This is a simple statistical study. Lets say if you have 20,000 people working with you. Doing this study manually without statistics would take a very long time and possibility of error will also be very high. With statistics it takes only a few second to make a bar chart on Microsoft Excel.
Just one glance at the chart and you see the bar on Friday or Monday or both three times higher than other weekdays. Like they say a picture is worth a thousand words.
This information can help the management to take proper measures to reduce the number of unscheduled leaves on Fridays and Mondays.
Different between single task and multitasking?
In a 'single tasking' environment, only one task is given to the processor at a time & the processor takes millisecond to execute that task. For example, a student is writing a program which takes say, 10 minutes. During this time, the processor is sitting idle. When the program is given to the processor, it finishes its execution in a millisecond. This way, processor is wasting a lot of time which is a dawback in 'single tasking'.
In a 'Multi tasking' environment, processor time is divided equally. For example, there are 4 tasks to execute. This is divided into 1/4 millisecond time for each job. This small part is called 'time slice'. Within this time slice, it will try to execute each job. If it can't, intermediate result will be stored in temporary memory. Once executing the fourth task, it will come back to the first task, in a circular manner. This is called 'round robin' method.
The main difference is that, in single tasking, the processor time is wasted, but in multitasking, we can utilize the processor time in an optimum way.
What does it mean when there is a decimal right after echo no space on a batch file?
A period right after the "echo" command would echo an empty line.
What are row level and statement level triggers?
The FOR EACH ROW option determines whether the trigger is a row trigger or a statement trigger. If you specify FOR EACH ROW, then the trigger fires once for each row of the table that is affected by the triggering statement. The absence of the FOR EACH ROW option indicates that the trigger fires only once for each applicable statement, but not separately for each row affected by the statement.
How can you populate a Dropdown with an Array from a Database using PHP?
This can be done with any Database system as the clever part is within the PHP.
There are two ways of doing this. The first method is having each record as a new selection. The second is having one field of the selection.
I'm going to use 'DATABASE {' and '} DATABASE' in order to show you where to put your 'Database {' and your closing '}' for the query.
Each Record
Assuming that you have at least two fields. One called value one called text then the following would work. (If your value is always the same as the Text shown to the user then you can change the set of text to value)
Echo '<select name="myselect">';
#DATABASE {
$current_value = $DATABASE['value'];
$current_text = $DATABASE['text'];
$myarray[] = '<option value="' . $current_value . '">' . $current_text . '</option>'; #A*
} DATABASE
Foreach($myarray as $key => $value){
Echo $value;
}
Echo '</select>';
Of course in this method you do not require an array as such. Due to the fact that on line A* could echo the value there and then.
One Field
This would be used more in the cases in which the table is built for forms and works like a Content Management System (CMS).
Firstly set out your record contents as: (I'm assuming here that the field is called dropdown)
I am a value[nowtext]I am some text[nextopt]I am a second Value[nowtext]I am some more text
Now let me explain. If you split this up in to [nextopt] there are two options. If you then split each again by [nowtext] you'll find 2 in between the [nextopt].
In this case, the first item set is the value of the Dropdown. The second is then the text and is split using [nowtext].
There are two functions in PHP which will help us. The first is called explode(); and this works like myfeild.split(); in Javascript. The second is implode();. Explode() is making an array. Think of it as, Explode the information into smaller chunks. Implode is the opposite, this takes an Array and turns it in to a String. (I've added two links to W3schools for reference on these tags)
Fairly simple when you understand how they work. Here's an example:
Echo '<select name="myselect">';
#Database {
$current_dropdown = $DATABASE['dropdown'];
$dropdown_array_a = explode('[nextopt]',$current_dropdown); #Makes an array
Foreach($dropdown_array_a as $key => $value){ #Runs for each item in array and loads in the key and the value of the array.
$dropdown_array_b = explode('[nowtext]',$value
Echo '<option value="' . $dropdown_array_b[0] . '">' . $dropdown_array_b[1] . '</option>';
}
# } DATABASE
Echo '</select>';
That was two of the many ways to perform this task. A link to the reference of Explode, Implode, Arrays and Foreach has been added to the Question.
What are the three basic needs of primitive people are?
The three things you'll need are (1) Water for Drinking and Sanitation; (2) a Shelter from the elements; and (3) a viable food source.
Fire is a great invention as was the wheel, edged weapons, and guns. You can live without fire, a knife and a rifle/gun in the Outback or Desert, however, I wouldn't enjoy it. After Water, Food, and Shelter, comes a good Knife. (And if you're thinking you need fire to kill the germs in water, yeah, that's one way, so is iodine but you can use the Sun, a t-shirt, and let it drip through to a Canister to clean water for drinking and sanitation.)
To stay alive you have to drink water and eat and you need at least a basic kind of shelter to warm yourself and stay out of the elements, even in the snow you can dig a hole and live in the hole while a snowstorm rages overhead--you'll be warm, you can drink the snow, and even make and keep going a fire, however, fire in a snowstorm isn't going to be around for very long. The fourth thing, were there to be four, would be fire of course, it's a great way to make sure you're drinking water without getting sick, can make a meal a lot better than it would have been by cooking it, and within the shelter, a good heath makes the cold ground a lot warmer and comfortable. Also, you can clean a wound with fire and boiled wine for an infection from skin rot or to cauterize a wound taken from a battle or from a hunt for food.
Difference between rdbms and dbms?
dbms stands for data base management system whereas rdbms is relational data base management system.
A Database Management System (DBMS) is collection of software programs which enable large, structured sets of data to be stored, modified, extracted and manipulated in different ways. Whereas Relational Database Managemet System (RDBMS) is a data structured in database tables, fields and records. Each RDBMS tables consist of database table rows.
class in dbms is nothing but a collection of attributes....
class in java is defined as collection of objects....:D
Meaning of secondary key with examples?
An attribute or set of attributes that is basis for retrieval is known as secondary key
for example, address in student table can be used to display all students who are living in a particular city. in this case, address will be used as secondary key
What can trigger the knifelike pain of trigeminal nerualgia?
Stimulation of the face, lips, or gums, such as talking, eating, shaving, tooth-brushing, touch, or even a current of air, may trigger the severe knifelike or shocklike pain of trigeminal neuralgia.
Does Access designate the first field as the primary key field?
No. It does not designate any field you put in. That is something you have to do yourself. If you don't designate one, then it will ask you if you want to or if Access can put one in for you. If you allow Access to put one in, then it will insert a nwe field which will be an Autonumber field and this will be inserted at the top and so it will be the first field. It makes sense to have the first field as a key field, which is why it inserts it at the top, before the first field you put in. If you are setting your own, you should put that field in first, though you do not have to.
