What Can The Sqldataadapter Update () Method Do?
What is the use of SqlDataAdapter in C#? The DataAdapter uses the Connection object of the . NET data provider to connect to a data source, and Command objects to retrieve data from and resolve changes to the data source. The SelectCommand property of the DataAdapter is a Command object that retrieves data from the data source.
Which method of DataSet updates the original data source? The Update method of the DataAdapter is called to resolve changes from a DataSet back to the data source. The Update method, like the Fill method, takes as arguments an instance of a DataSet , and an optional DataTable object or DataTable name.
Which method is called for a DataSet to accept all the changes made to the DataSet? Calling the AcceptChanges method or AcceptChanges method will commit all changes in the DataSet or DataTable.
What Can The Sqldataadapter Update () Method Do? – Related Questions
Which is better DataReader or DataAdapter?
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. A DataAdapter is used to retrieve data from a data source and populate tables within a DataSet.
Which is faster DataSet or DataTable?
DataTables should be quicker as they are more lightweight. If you’re only pulling a single resultset, its your best choice between the two.
Which is faster SqlDataAdapter and SqlDataReader?
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 ExecuteReader in C#?
The ExecuteReader() in C# SqlCommand Object sends the SQL statements to the Connection Object and populate a SqlDataReader Object based on the SQL statement. When the ExecuteReader method in SqlCommand Object execute , it will instantiate a SqlClient.
What is ExecuteScalar in C#?
ExecuteScalar method is used to execute SQL Commands or storeprocedure, after executing return a single value from the database. It also returns the first column of the first row in the result set from a database.
What property is used on the DataTable to indicate conflicts after update method is called?
What property is used on the datatable to indicate conflicts after update method is called? There is no such property called ‘HasErrorConflict’ in . net. The correct answer is ‘HasError’.
What is concurrency violation?
The concurrency violation occurs when I run the project, add a record and save it, make a change to the same record and then save it. The full error message reads: Concurrency violation: the UpdateCommand affected 0 of the expected 1 records. Include logic in your application to handle concurrency violations.
What are the three main objects of DataSet?
ANSWER: DataTable, DataColumn, and DataRelation.
How do you fill a dataset?
The Fill method of the DataAdapter is used to populate a DataSet with the results of the SelectCommand of the DataAdapter . Fill takes as its arguments a DataSet to be populated, and a DataTable object, or the name of the DataTable to be filled with the rows returned from the SelectCommand .
Is ADO.NET still used?
So yes: there’s definitely still room for “classic” ADO.NET to “fill the gaps” where EF/L2S or other technologies don’t really offer anything useful.
How do you describe a data set?
A data set (or dataset) is a collection of data. In the case of tabular data, a data set corresponds to one or more database tables, where every column of a table represents a particular variable, and each row corresponds to a given record of the data set in question.
Is DataReader faster than DataTable?
We ended up writing some benchmarks to test the speed differences. 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.
Is it necessary to manually close and dispose of SqlDataReader?
You must ensure the Close method is called when you are through using the SqlDataReader before using the associated SqlConnection for any other purpose. Do not call Close or Dispose on a Connection, a DataReader, or any other managed object in the Finalize method of your class.
What is the difference between ExecuteNonQuery () and ExecuteScalar ()?
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.
Why do we use DataSet?
The purpose of DataSets is to avoid directly communicating with the database using simple SQL statements. The purpose of a DataSet is to act as a cheap local copy of the data you care about so that you do not have to keep on making expensive high-latency calls to the database.
What is difference between DataTable and DataSet?
1) A DataTable is an in-memory representation of a single database table which has collection of rows and columns whereas a DataSet is an in-memory representation of a database-like structure which has collection of DataTables. A dataset is an in-memory representation of a database-like structure.
Why constraints are used in SQL?
SQL constraints are used to specify rules for the data in a table. Constraints are used to limit the type of data that can go into a table. This ensures the accuracy and reliability of the data in the table. If there is any violation between the constraint and the data action, the action is aborted.
What is the difference between connected and disconnected environments?
A connected environment requires a constant connection to transfer data between the client application and the data source. However, a disconnected environment retrieves data and performs modification without a constant connection to the network.
What is SQL adapter in C#?
The ADO.NET SqlDataAdapter in C# works as a bridge between a DataSet and a data source (SQL Server Database) to retrieve data. The SqlDataAdapter 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.
What is the use of execute scalar?
Use the ExecuteScalar method to retrieve a single value (for example, an aggregate value) from a database. This requires less code than using the ExecuteReader method, and then performing the operations that you need to generate the single value using the data returned by a SqlDataReader.
What is difference between ExecuteNonQuery and executeQuery?
Moreover the executeQuery() is not used in . net but it is used in JAVA. ExecuteNonQuery: Executes Insert, Update, and Delete statements (DML statements) and returns the number of rows affected.