How does ExecuteNonQuery differ from the Remove method?

ExecuteNonQuery removes data in bulk based on criteria (SQL WHERE clauses) matching indexed attributes, in contrast to the usual `Remove` function, which requires particular keys to delete items.

What does ExecuteNonQuery return?

The `ExecuteNonQuery` method returns an integer value indicating the amount of rows (cache items) impacted or removed by the query.

Do I need to configure indexes to use ExecuteNonQuery?

Any property used in the criteria must be indexed in NCache before the query may execute since `ExecuteNonQuery` depends on SQL-like queries with WHERE clauses.

Delete Data with ExecuteNonQuery

ExecuteNonQuery is an API in NCache that uses a SQL-like DELETE statement to remove data on the basis of specified criteria (indexed attributes). ExecuteNonQuery efficiently deletes all items that meet a query clause (e.g., DELETE FROM Product WHERE UnitsInStock = 0) and returns the number of impacted rows, in contrast to the conventional Remove function, which requires specified keys.

Important

The Delete statement can only be executed through ExecuteNonQuery.

Prerequisites

To learn about the standard prerequisites required to work with all NCache client-side features, please refer to the given page on Client-Side API Prerequisites.
Searchable objects and their attributes must be indexed by either configuring indexes or defining indexes programmatically.
For API details, refer to: ICache, ICacheReader, ExecuteReader, SearchService, QueryCommand, ExecuteNonQuery.

Create a new Console Application.
Install either of the following NuGet packages in your .NET client application:
- Enterprise: Install-Package Alachisoft.NCache.SDK -Version 4.9.1.0
- Professional: Install-Package Alachisoft.NCache.Professional.SDK -Version 4.9.1.0
Make sure that the data being added is serializable.
Add NCache References by locating %NCHOME%\NCache\bin\assembly\4.0 and adding Alachisoft.NCache.Web and Alachisoft.NCache.Runtime as appropriate.
Include the Alachisoft.NCache.Web.Caching namespace in your application.
To learn more about the NCache Legacy API, please download the NCache 4.9 documents available as a .zip file on the Alachisoft Website.

The following example deletes all products from the cache where UnitsInStock is equal to 0, using ExecuteNonQuery:

// Precondition: Cache is already connected
// Items are already present in the cache
// Provide Fully Qualified Name (FQN) of your custom class
string query = "DELETE FROM FQN.Product WHERE UnitsInStock = ?";

// Use QueryCommand for query execution
var queryCommand = new QueryCommand(query);
queryCommand.Parameters.Add("UnitsInStock", 0);

// Execute query
_cache.SearchService.ExecuteNonQuery(queryCommand);

// Precondition: Cache is already connected
// Items are already present in the cache
// Provide Fully Qualified Name (FQN) of your custom class
String query = "DELETE FROM FQN.Product WHERE UnitsInStock = ?";

// Use QueryCommand for query execution
QueryCommand queryCommand = new QueryCommand(query);
queryCommand.getParameters().put("UnitsInStock", 0);

// Execute query
int affectedRows = cache.getSearchService().executeNonQuery(queryCommand);

# Precondition: Cache is already connected
# Items are already present in the cache
# Provide Fully Qualified Name(FQN) of your custom class
query = "DELETE FROM FQN.Product WHERE units_in_stock = ?"

# Use QueryCommand for query execution
query_command = QueryCommand(query)
query_command.set_parameters({"units_in_stock": 0})

# Execute query
rows_affected = cache.get_search_service().execute_non_query(query_command)

// This is an async method
// Precondition: Cache is already connected
// Items are already present in the cache
// Provide Fully Qualified Name (FQN) of your custom class
var query = "DELETE FROM FQN.Product WHERE UnitsInStock = ?";

// Use QueryCommand for query execution
var queryCommand = new QueryCommand(query);

// Providing parameters for query
let parameter = new Map();
parameters.set("UnitsInStock", 0);
queryCommand.setParameters(parameters);

// Execute query
const searchService = await cache.getSearchService();
let rowsAffected = await searchService.executeNonQuery(queryCommand);

// Using NCache Enterprise 4.9.1
// Precondition: Cache is already connected
// Items are already present in the cache
// Provide Fully Qualified Name (FQN) of your custom class
string query = "DELETE Alachisoft.NCache.Sample.Data.Product WHERE this.UnitsInStock = ?";

// Set parameters
Hashtable parameters = new Hashtable();
parameters.Add("UnitsInStock", 0);

// Execute query
int affectedRows = cache.ExecuteNonQuery(query, parameters);

Note

To ensure the operation is fail-safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.

Additional Resources

NCache provides a sample application for SQL Queries on GitHub.

Delete Data with ExecuteNonQuery

Important

Prerequisites

Note

Additional Resources

See Also

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