Updating the database

For more information and an example, see Retrieving Identity or Autonumber Values. In many circumstances, the order in which changes made through the DataSet are sent to the data source is important.

For example, if a primary key value for an existing row is updated, and a new row has been added with the new primary key value as a foreign key, it is important to process the update before the insert. You can then pass the returned DataRow array to the Update method of the DataAdapter to process the modified rows.

By specifying a subset of rows to be updated, you can control the order in which inserts, updates, and deletes are processed. For example, the following code ensures that the deleted rows of the table are processed first, then the updated rows, and then the inserted rows. The sample uses DataAdapter. AcceptChangesDuringFill to clone the data in the database. If the property is set as false, AcceptChanges is not called when filling the table, and the newly added rows are treated as inserted rows.

So, the sample uses these rows to insert the new rows into the database. The samples uses DataAdapter. TableMappings to define the mapping between the source table and DataTable. When you create a DataTable, you can only write the data from database to the current version or the original version by setting the property as the LoadOption. Upsert or the LoadOption. The sample will also update the table by using DbDataAdapter. UpdateBatchSize to perform batch operations. Skip to main content.

This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Is this page helpful? Please rate your experience Yes No. Databases can be relational and non-relational, depending on the type of information the user wants to store. Relational databases are those in which data is stored in the form of rows and columns in a table, whereas non-relational databases do not use tabular format to store the data; instead, the data is stored either in graphical, document, columnar or key-value form.

SQL is a relational database and hence stores the values in rows and columns format. Every column in SQL is called a field that is designed to store specific information about a record. Columns have a vertical structure in SQL, and rows have a horizontal. Before storing and accessing any information in a database, the first step is to create a database.

It is necessary that the user must have admin privileges to create a new database. It will create a new database in SQL with the name employees. We can also check the above-created DB using the command given below:.

Dropping a database means deleting an existing database from SQL Server. It is a good practice to delete the database that is not in use as it saves memory. Users must have admin privileges to drop the database. It is crucial for datasets in database systems to stay up-to-date with the ever-changing, real-world data, and the UPDATE command in SQL enables users to do exactly that.

You never have to worry about an outdated dataset. This command is a simple, yet powerful tool available to us. This is an essential step to moving forward in your journey to becoming an SQL expert.

This comprehensive program covers SQL in-depth, and earning your certification in this field can help to jumpstart your career. Do you have any questions for us? Data Science vs.