Java get data from database example download

This tutorial helps you write Java code to export data from a table in database to an Excel file — a very common task of a software program.

Java get data from database example download

The following code is for a simple Java program that connects to a MySQL database, reads all rows from the Review table and writes the data to an Excel file:.

Note that the writeHeaderLine method writes the column names of the table to the first line in the Excel file. The column names are known beforehand and fixed. The first column ID is omitted. The writeDataLines method iterates over all rows in the result set returned from the database, and writes data to the Excel file.

Run this program, you will see the Reviews-export. Open this file by Microsoft Excel application and you will see:. Following is the full code:. In this program, the name of the Excel file is generated based on table name followed by the current datetime — as you can see in the getFileName method.

Note that this program excludes the first column of the table, which is supposed to be the ID column. Notify me of follow-up comments. Java code example to export data from database to Excel file. He started programming with Java in the time of Java 1. Make friend with him on Facebook and watch his Java videos you YouTube. This Code is very useful to me Thank you. Refresh comments list.The format is: String id, String name, Double rate example: "1", "Alabama".

Some of your past answers have not been well-received, and you're in danger of being blocked from answering. Java getting data from a database with an SQL statement 1. My question: How do I properly get a list of names from a table? MykhailoMoskura I added it in. It is now working fine or you are having different error? Nicholas Nov 20 at Sign up or log in StackExchange.

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Sign up using Google. This page is only for reference, If you need detailed information, please check here. Popular posts from this blog TypeORM how to seed database. Coming from Entity Framework, it was very easy to seed the db with a few lines such as Database. Is there a similar approach to seed the database in TypeOrm? If not, what is the recommended way of doing it?

Read more. But I'm trying to access the data without typecasting it to a particular class and I'm getting null value. But I'm trying to access the data without typecasting it to a particular class and I'm getting nul…. Net Web Api that is capable of sending emails. I managed in sending the email but only with a simple template stored in a variable, locally. Create config ; if File. RunCompile filePath, null, email ; mail.Once a connection is made, you can begin working with the database in the IDE, allowing you to create tables, populate them with data, run SQL statements and queries, and more.

Therefore, you can skip ahead to Starting the Server and Creating a Database. Run the self-extracting file. A folder named 'javadb' will be created in the same location as the file.

On your system, create a new directory to be used as a home directory for the individual instances of the database server. The bin subdirectory contains the scripts for executing utilities and setting up the environment.

Example to retrieve file from Oracle database:

The javadoc subdirectory contains the API documentation that was generated from source code comments. This contextual menu items allow you to start and stop the database server, create a new database instance, as well as register database servers in the IDE as demonstrated in the previous step.

To start the database server:. Note the following output in the Output window, indicating that the server has started:. After you create the database, if you expand the Databases node in the Services window you can see that the IDE created a database connection and that the database was added to the list under the Java DB node.

So far, you have successfully started the the database server and created a database instance named contact in the IDE. In the Services window of the IDE you can perform the following common tasks on database structures. In order to begin working with the contact database, you need to create a connection to it.

To connect to the contact database perform the following steps. Expand the Databases node in the Services window and locate the new database and the database connection nodes. The database connection node is displayed under the Databases node. The name of the database is displayed under the Java DB node. The connection node icon appears wholesignifying that the connection was successful. The contact database that you just created is currently empty. It does not yet contain any tables or data.

You can explore both methods:. Expand the Contact DB connection node and note that there are several schema subnodes. The app schema is the only schema that applies to this tutorial. For Column Name, enter id. Under Constraints, select the Primary Key checkbox to specify that this column is the primary key for your table. All tables found in relational databases must contain a primary key.

Note that when you select the Primary Key check box, the Index and Unique check boxes are also automatically selected and the Null check box is deselected. This is because primary keys are used to identify a unique row in the database, and by default are used as the table index.In those examples I showed how to connect to two different databases so you could see how little the code changes when you switch from one database to another.

As you can see, the Customers table contains these four sample records. The hardest part of the process is defining the query you want to run, and then writing the code to read and manipulate the results of your SELECT query. This statement returns each Lname last name record from the Customers database, where Snum salesperson id-number equals In plain English, you might say "give me the last name of every customer where the salesperson id-number is ".

Now that we know the information we want to retrieve, how do we put this SQL statement into a Java program?

Java get data from database example download

It's actually very simple. In the first step, I create a Java Statement objection from the Connection object. That's really just an intermediate step that lets us do what we want to do in the next step: Execute our query, and get a ResultSet object.

The ResultSet object rs now contains the results from the database query. Now we can work with those results. Well, JDBC makes this pretty easy also. In many cases, you can just use the next method of the ResultSet object. After the previous two lines, you might add a loop like this to read the results:. This loop reads the last name returned in each record, and prints it to the screen using the normal System. In the case of our sample database, the printed results look like this:.

Notice that in this example all we're doing is printing our results. In many JDBC applications, you'll probably want to do something else with the results, such as displaying them in a table or grid in a GUI applet or application.

The source code for the Query1. If you're interested, you can download the Java source code for our Query1. Just 1 create a ResultSet object, 2 execute the query, and then 3 read the results. By Alvin Alexander.

Last updated: November 21, Springfield MacBeal Ms. Boston Flinstone Mr. Bedrock Cramden Mr. New York As you can see, the Customers table contains these four sample records. Drilling in my head again. My favorite part of doing lower-body yoga work.Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.

The following method, CoffeesTable. A ResultSet object is a table of data representing a database result set, which is usually generated by executing a statement that queries the database. For example, the CoffeeTables. You access the data in a ResultSet object through a cursor.

Note that this cursor is not a database cursor. This cursor is a pointer that points to one row of data in the ResultSet. Initially, the cursor is positioned before the first row. The method ResultSet. This method returns false if the cursor is positioned after the last row. This method repeatedly calls the ResultSet. The ResultSet interface provides methods for retrieving and manipulating the results of executed queries, and ResultSet objects can have different functionality and characteristics.

These characteristics are type, concurrency, and cursor holdability. The type of a ResultSet object determines the level of its functionality in two areas: the ways in which the cursor can be manipulated, and how concurrent changes made to the underlying data source are reflected by the ResultSet object. The sensitivity of a ResultSet object is determined by one of three different ResultSet types:.

The method DatabaseMetaData. The concurrency of a ResultSet object determines what level of update functionality is supported. The method CoffeesTable. Calling the method Connection. In some cases, however, this may not be the desired behavior.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I've connected to a MySQL database, which contains four fields the first of which being an ID, the latter ones each containing varchar strings. I am trying to get the last row of the database and retrieve the contents of the fields so that I can set them to variables an int and three strings and use them later.

So far, I have the bare minimum to make the connection, where do I go from here? As you can see I have tried to write a SQL statement to get the last row but it's all gone wrong from there and I don't know how to split it into the separate fields. In rs. Moves the cursor froward one row from its current position. A ResultSet cursor is initially positioned before the first row; the first call to the method next makes the first row the current row; the second call makes the second row the current row, and so on.

When a call to the next method returns false, the cursor is positioned after the last row. If an input stream is open for the current row, a call to the method next will implicitly close it. A ResultSet object's warning chain is cleared when a new row is read. Returns: true if the new current row is valid; false if there are no more rows Throws: SQLException - if a database access error occurs or this method is called on a closed result set.

As for your use of Class. Driver" as its not necessary to initiate it yourself. Learn more. Asked 7 years, 10 months ago.

Uploading and downloading files from Database using Java Servlet

Active 6 years, 8 months ago. Viewed 98k times. Active Oldest Votes. Here you go : Class. Returns: true if the new current row is valid; false if there are no more rows Throws: SQLException - if a database access error occurs or this method is called on a closed result set reference.

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David Kroukamp David Kroukamp This should work, I think Why does results. It moves to the next row available initially it's before the first rowif there's none it returns false, so it fails; otherwise it returns true and it continues. Simran Sharma Simran Sharma 19 2 2 bronze badges. Sign up or log in Sign up using Google.

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Sign up using Email and Password.They are so inconsistent and I am trying to work out what they are due - a loss, I think - sorry Gunners fans. This early spell is when Sam Allardyce usually has a big effect on results, but I think Liverpool might alter that statistic on this occasion.

Media playback is not supported on this deviceBecause of their Europa League tie on Thursday, Allardyce will not have had much time to train with his squad, Everton ship a lot of goals and boy do Liverpool like scoring them at the moment. The Reds record in front of goal is just staggering, as is the amount of chances they are creating at the moment too,It will not be one-way traffic - it is a derby, and I know what kind of games they are - but even if it is a lot tighter, I cannot see Liverpool making lots of chances without taking a couple of them.

Richard's prediction: I think this will be a cracking game - they always seem to be - and I think there will be a few goals. I am backing Liverpool to win it, because they are at home. I just think United have hit a run of form, and their win at Arsenal last week was very comfortable and impressive.

If Kompany is missing, that will give United more opportunities from set-pieces and, although City will create plenty of chances themselves, David de Gea is obviously in such fine form in goal for Jose Mourinho's side. The key will be what Mourinho tries tactically. You know he will have a plan, and he will have had a team in mind for the past three or four matches too.

So Pogba's suspension is a blow for him as far as that is concerned, but I just have a feeling United will go and beat City, in not a particularly good game. Richard's prediction: City look absolutely unstoppable - what a pleasure it has been watching them this season. If anyone can stop them, it's Jose Mourinho, but I don't think that he can.

Java get data from database example download

He beat comedian Nish Kumar who got six correct results, but with no perfect scores, giving him 60 points. Bodyline, a "heart-stopping" win and Mitchell Johnson's pace assault - what is the most memorable moment from England's Ashes tours. Stifling Smith and scoring centuries - what lessons can England learn from defeats in the first two Ashes Tests. Get latest scores and headlines sent straight to your phone, sign-up to our newsletter and learn where to find us on online.

The latest rumours and stories from around the world of football. Enjoy the best debate, analysis and interviews with 5 live and World Service football plus our commentary listings. How to get into football - the most popular sport in the world, with clubs and facilities throughout the UK. The BBC is not responsible for the content of external sites. Read about our approach to external linking. Check out our full list of predictions for today's and tonight's games (Sunday December 10th, 2017) below.

Java servlet to download file from database

Click on a date to view predictions for tomorrow and this weekend, or click on a past date to view historical predictions and our success rates. BTTS reflects to whether both teams will score in the match (Yes or No). Each team's last 5 games record is displayed from left to right, with the most recent result (Won, Drawn or Lost) on the right.

how to fetch data in table format using servlet with ecllipse ide

Click any selections below for upcoming or in play games to add your bets straight to your bet slip. Click here to see how you can contact us)LLWLDSouthampton v ArsenalLWWWL3. Merse was about par for the course in last weekend, with six correct results and one correct scoreline.

Live on These aren't the games that matter for West Ham. Watford are really good away from home and Burnley haven't been as good at home, so you'd expect an away win, but I think Burnley will sneak this one. Burnley are just solid. They have had some really good results, so they are so hard to bet against. They are going to get it right at home soon.

They are right in it now, and a win here will really help them out. Brighton 1-5 Liverpool Brighton 1-5 Liverpool Bournemouth won't be able to cope with Wilfried Zaha.

They can attack at will, but sometimes when quality players get at them, they really can struggle. It will be a really good game, as both teams will have a go.


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