- DataReaders provide multiple asynchronous methods that can be employed. ...
- The Fill method of DataAdapter objects enables us to populate only DataSets and DataTables. ...
- The Fill method of the DataAdapter completes only when all the data has been retrieved and added to the DataSet or DataTable. ...
What is the difference between DataReader and DataAdapter in Java?
DataAdapter object is used to read the data from database and populates that data to DataSet whereas DataReader simply reads the data using the Read () method.
What is a DataAdapter?
A DataAdapter is an object that contains four DbCommand objects: one each for SELECT, INSERT, DELETE and UPDATE commands. It mediates between these commands and a DataSet though the Fill and Update methods.
What is the difference between DataTable and DataAdapter?
DataTable is mainly used to fetch and hold the records of one single table into memory. A DataAdapter is used to populate DataTable from records returned from an SQL statement and also a DataTable can be created in memory and data can be added to it.
What is the difference between a dataset and a DataReader?
DataSet is an in-memory datastore, whereas datareader is just a medium to retrieve the data. On a lighter note, you can run Linq queries on DataSet, but not on a datareader. – Partha Choudhury Nov 4 '09 at 21:45
Which is better DataReader or DataAdapter?
Using a DataReader produces faster results than using a DataAdapter to return the same data. Because the DataAdapter actually uses a DataReader to retrieve data, this should not surprise us.
When should I use DataReader and DataAdapter?
DataReader requires an open connection in order to execute the SQL statement. Example would be fetching Name City for all records in the Person Table using DataReader. DataAdapter is used to execute SQL statements and is used to populate the results of SQL Query into a DataSet or DataTable.
What is the difference between DataReader and DataSet object?
Dataset or DataReader? The DataSet class in ADO.Net operates in an entirely disconnected nature, while DataReader is a connection oriented service. DataSet is an in-memory representation of a collection of Database objects including related tables, constraints, and relationships among the tables.
What is DataAdapter used for?
A DataAdapter is used to retrieve data from a data source and populate tables within a DataSet. The DataAdapter also resolves changes made to the DataSet back to the data source. The DataAdapter uses the Connection object of the .
Is DataReader faster than DataTable?
It was generally agreed that a DataReader is faster, but we wanted to see how much faster. The results surprised us. The DataTable was consistently faster than the DataReader. Approaching twice as fast sometimes.
Which is faster DataSet or DataReader?
A great plus about DataSet is that it can be filled using multiple data sources. The DataSet represents a complete set of data among the tables that include related tables, constraints, and relationships. However, this greater functionality comes with performance overhead; therefore, DataSet is slower than DataReader.
What is the difference between ExecuteScalar ExecuteReader and ExecuteNonQuery?
Solution 1. ExecuteScalar() only returns the value from the first column of the first row of your query. ExecuteReader() returns an object that can iterate over the entire result set. ExecuteNonQuery() does not return data at all: only the number of rows affected by an insert, update, or delete.
What is difference between DataTable and DataSet?
A DataTable object represents tabular data as an in-memory, tabular cache of rows, columns, and constraints. The DataSet consists of a collection of DataTable objects that you can relate to each other with DataRelation objects.
What is the difference between SqlDataReader and SqlDataAdapter?
A SqlDataAdapter is typically used to fill a DataSet or DataTable and so you will have access to the data after your connection has been closed (disconnected access). The SqlDataReader is a fast forward-only and connected cursor which tends to be generally quicker than filling a DataSet/DataTable.
What is DataReader object?
In ADO.NET, a DataReader is a broad category of objects used to sequentially read data from a data source. DataReaders provide a very efficient way to access data, and can be thought of as a Firehose cursor from ASP Classic, except that no server-side cursor is used.
What is a DataAdapter class?
DataAdapter is a class that represents a set of SQL commands and a database connection. It can be used to fill the DataSet and update the data source.
Which one is a DataAdapter object?
DataAdapter is a part of the ADO.NET Data Provider. DataAdapter provides the communication between the Dataset and the Datasource. We can use the DataAdapter in combination with the DataSet Object. That is these two objects combine to enable both data access and data manipulation capabilities.
What is the difference between a DataReader and a DataAdapter?
DataAdapter is an intermediate layer/ middleware which acts a bridge between the DataSet and a Database where as DataReader provides forward-only, read-only access to data using a server-side cursor (simply put it is ued to read the data).
Is DataReader read only?
DataReader is a stream which is readonly and forward only. DataReader releasese the records as query executes and do not wait for the entire query to execute. Therefore it is very fast as compare to the dataset. It releases only when read method is called.
What is a data set?
DataSet is a disconnected orient architecture that means there is no need of active connections during work with datasets and it is a collection of DataTables and relations between tables. It is used to hold multiple tables with data. You can select data form tables, create views based on table and ask child rows over relations. Also DataSet provides you with rich features like saving data as XML and loading XML data.
What is datareader used for?
DataReader is used to read the data from database and it is a read and forward only connection oriented architecture during fetch the data from database. DataReader will fetch the data very fast when compared with dataset. Generally we will use ExecuteReader object to bind data to datareader.
What is a data table?
DataTable represents a single table in the database. It has rows and columns. There is no much difference between dataset and datatable, dataset is simply the collection of datatables.
How many times can you iterate over a record?
You can iterate over it as many times as you need , or even look up a specific record by index
How does ADO.NET DataReader work?
You can use the ADO.NET DataReader to retrieve a read-only, forward-only stream of data from a database. Results are returned as the query executes, and are stored in the network buffer on the client until you request them using the Read method of the DataRea der. Using the DataReader can increase application performance both by retrieving data as soon as it is available, and (by default) storing only one row at a time in memory, reducing system overhead.
What is a data adapter?
A DataAdapter is used to retrieve data from a data source and populate tables within a DataSet. The DataAdapter also resolves changes made to the DataSet back to the data source. The DataAdapter uses the Connection object of the .NET Framework data provider to connect to a data source, and it uses Command objects to retrieve data from and resolve changes to the data source.
What to do if you don't need to keep data in memory?
If you want to deal with your data in a disconnected fashion choose the DataAdapter to fill either a DataSet or DataTable.
What is the difference between SQLDataReader and SQLDataAdapter?
Essentially, the major difference for me that usually influences my decisions on which to use is that with a SQLDataReader, you are "stream ing" data from the database. With a SQLDataAdapter, you are extracting the data from the database into an object that can itself be queried further, as well as performing CRUD operations on.
What is a SQLDataReader?
The SqlDataReader is a fast forward-only and connected cursor which tends to be generally quicker than filling a DataSet/DataTable.
How many reputations do you need to answer a highly active question?
Highly active question. Earn 10 reputation (not counting the association bonus) in order to answer this question. The reputation requirement helps protect this question from spam and non-answer activity.
Does SQLDataReader have memory?
Furthermore, with a SqlDataReader, you deal with your data one record at a time, and don't hold any data in memory. Obviously with a DataTable or DataSet, you do have a memory allocation overhead. If you don't need to keep your data in memory, so for rendering stuff only, go for the SqlDataReader.
When to use SQLDataAdapter?
Use an SqlDataAdapter when wanting to populate an in-memory DataSet/DataTable from the database. You then have the flexibility to close/dispose off the connection, pass the datatable/set around in memory. You could then manipulate the data and persist it back into the DB using the data adapter, in conjunction with InsertCommand/UpdateCommand.
What is a dataset in SQL?
DataSet is mainly used to fetch and hold the records for one or more tables into memory. A DataAdapter is used to populate DataSet from records returned from an SQL statement and also a DataSet can be created in memory and tables and data can be added to it. DataSet can also be converted and saved as XML file.
How does a datareader work?
DataReader is ReadOnly and it fetches one row at a time in memory and hence it has less load on memory. The Read function of the DataReader reads one row at a time in memory and if a row is read then the function returns True else False. DataReader requires an open connection in order to execute the SQL statement.
What is a data reader?
DataReader as the name suggests reads data. DataReader is used for fetching records from the SQL Query or Stored Procedure i.e. SELECT Operation. DataReader is the fastest technique to fetch records from database and it works only in Forward direction meaning a row read once cannot be read again.
Is DataAdapter slower than DataReader?
DataAdapter gets all the rows of the executed SQL statement at once and populates into DataSet or DataTable in memory and hence DataAdapter is bit slower compared to DataReader.
Can a data set be converted to XML?
DataSet can also be converted and saved as XML file .
How does a datareader work?
One typical way to get a DataReader is by using the ExecuteReader () method of a DbCommand.
What is data reader?
DataReader is connection-oriented, that means whenever we bind data from the database it must require a connection and after that disconnected from the connection. It has read-only access, we can’t do any transaction on them. It supports forward-only scanning of data, in other words, you can’t go backward.
What is dataset oriented?
Dataset is connection-less oriented, that means whenever we bind data from the database it connects indirectly to the database and then disconnected. It has read/write access to data tables. It supports both forward and backward scanning of data.
How many datareaders are there in a data adapter?
The DataAdapter is an compound object, in the sense that it internally comprises of 4 DataReader objects. Each of the DataReader objects are meant to perform CRUD (Create Retrieve Update Delete) - the Insert, Update, Delete and Select statements one runs on any datasource. Inside each of these DataReader objects, a DataConnection object is encapsulated. Thus, you can define different datasources for each of these DataReader objects inside the DataAdapter object. The DataAdapter provides the bridge between the datasource (database, for example), and the DataSet.
What is a datareader?
The DataReader, as the name suggests, is an object that can be used to provide a Read-Only-Forward-Only model to extract data from the Database and use in your .NET application. It is the direct implementation of the RecordSet model that one uses in legacy languages like VB6 or VC++.
What is a data table?
DataTable represents a single table in the database. It has rows and columns. There is no much difference between dataset and datatable, dataset is simply the collection of datatables.
What is a data set?
The DataSet is an object that is used to create/define an in-memory representation of the different data tables - like a typical Database (the DBMS model). It is normally adopted in disconnected a
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Recordings, events, heatmaps, and funnels will give you a complete overview about your app's users.
Is embedded C standard C?
First off— Yes, there really IS something officially called “Embedded C”, which is different than standard C. It’s defined in “ISO/IEC TR 18037:2008” which you can look up. (see also the draft spec “ISO/IEC JTC1 SC22 WG14 N1169”) See link below.
Is C# a platform dependent app?
Platform dependent. Although Microsoft has been pouring a lot of effort into .NET core its still nowhere near the quality of the .NET framework for Windows. This means that if you want to get the best performance possible on a C# app you’ll have to run it on Windows. With 95% of all servers and more than 60% of all mobile devices running on Linux (Android included) this makes C# pretty isolated and a real nightmare to use outside the Microsoft ecosystem.
