SQL IN Operator: Syntax and Usage

Note

This feature is only available in NCache Enterprise Edition.

In order to search the cache using SQL like query format with IN operator, you can specify multiple attribute values after the IN keyword. It means that ExecuteReader will search the cache for all the attributes provided after the IN keyword.

Prerequisites

Install the following NuGet package in your application:
- Enterprise: Alachisoft.NCache.SDK
Searchable objects and their attributes must be indexed by either configuring indexes or defining indexes programmatically.
Include the following namespaces in your application:
The cache must be running.
The application must be connected to cache before performing the operation.
For API details, refer to: ICache, ICacheReader, ExecuteReader, SearchService, QueryCommand.
Make sure that the data being added is serializable.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Add the following Maven dependency in your pom.xml file:

<dependency>
    <groupId>com.alachisoft.ncache</groupId>
    <artifactId>ncache-client</artifactId>
    <version>x.x.x</version>
</dependency>

Searchable objects and their attributes must be indexed by either configuring indexes or defining indexes programmatically.
Import the following packages in your application:
- import com.alachisoft.ncache.client.*;
- import com.alachisoft.ncache.runtime.caching.*;
- import com.alachisoft.ncache.runtime.exceptions.*;
The cache must be running.
The application must be connected to cache before performing the operation.
For API details, refer to: Cache, CacheReader, executeReader, getSearchService, QueryCommand.
Make sure that the data being added is serializable.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Indexing for searchable objects and their attributes need to be configured first as explained in Configuring Query Indexes in Administrator's Guide.
Install and include the following module in your application:
- Enterprise: const ncache = require('ncache-client')
Cache must be running.
The application must be connected to cache before performing the operation.
For API details, refer to: Cache, CacheReader, executeReader, getSearchService, QueryCommand.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Install the NCache Python client by executing the following command:

# Enterprise Client
pip install ncache-client

Indexing for searchable objects and their attributes need to be configured first as explained in Configuring Query Indexes in Administrator's Guide.
Import the NCache module in your application.
The cache must be running.
For API details, refer to: Cache, CacheReader, executeReader, getSearchService, QueryCommand
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Add the following Maven dependencies in your pom.xml file:

<dependency>
    <groupId>com.alachisoft.ncache</groupId>
    <artifactId>ncache-scala-client</artifactId>
    <version>x.x.x</version>
</dependency>

Indexing for searchable objects and their attributes need to be configured first as explained in Configuring Query Indexes in Administrator's Guide.
Import the following packages in your application:
- import com.alachisoft.ncache.scala.client.*;
- import com.alachisoft.ncache.scala.runtime.caching.*;
The cache must be running.
The application must be connected to cache before performing the operation.
For API details, refer to: Cache, CacheReader, SearchService, QueryCommand
Make sure that the data being added is serializable.
To ensure the operation is fail safe, it is recommended to handle any potential exceptions within your application, as explained in Handling Failures.
To handle any unseen exceptions, refer to the Troubleshooting section.

Syntax

Here's an example that retrieves ProductName and UnitsAvailable from the cache having either 10,15,20 or 25 UnitsAvailable using ExecuteReader.

try
{
    // Pre-condition: Cache is already connected
    // Items are already present in the cache
    // Write the query with the specified criteria
    // Use the Fully Qualified Name (FQN) of your own custom class
    string query = "SELECT ProductName, UnitsInStock From FQN.Product WHERE UnitsInStock IN (?, ?, ?, ?)";

    // Use QueryCommand for query execution
    var queryCommand = new QueryCommand(query);
    ArrayList parameters = new ArrayList();
    parameters.Add(10);
    parameters.Add(15);
    parameters.Add(20);
    parameters.Add(25);

    queryCommand.Parameters.Add("UnitsInStock", parameters);

    // Executing QueryCommand through ICacheReader
    ICacheReader reader = _cache.SearchService.ExecuteReader(queryCommand);

    // Check if result set is not empty
    if (reader.FieldCount > 0)
    {
      while (reader.Read())
      {
        // Get the value of the result set
        string ProductName = reader.GetValue<string>(1);
        int UnitsAvailable = reader.GetValue<int>(2);

      }
    }
    else
    {
      // Null query result set retrieved
    }
}
catch (OperationFailedException ex)
{
    if (ex.ErrorCode == NCacheErrorCodes.INCORRECT_FORMAT)
    {
        // Make sure that the query format is correct
    }
    else
    {
        // Exception can occur due to:
        // Connection Failures
        // Operation Timeout
        // Operation performed during state transfer
    }
}
catch (Exception ex)
{
  // Any generic exception like ArgumentException, ArgumentNullException
}

try
{
    // Pre-condition: Cache is already connected
    // Items are already present in the cache
    // Specify the query with the specified criteria
    // Use the Fully Qualified Name (FQN) of your own custom class
    String query = "SELECT productName, UnitsInStock From FQN.Product WHERE UnitsInStock IN (?,?,?,?)";

    // Use QueryCommand for query execution
    QueryCommand queryCommand = new QueryCommand(query);
    ArrayList parameters = new ArrayList();
    parameters.add(10);
    parameters.add(15);
    parameters.add(20);
    parameters.add(25);
    queryCommand.getParameters().put("UnitsInStock", parameters);

    // Executing QueryCommand through CacheReader
    CacheReader reader = cache.getSearchService().executeReader(queryCommand);

    // Check if result set is not empty
    if (reader.getFieldCount() > 0)
    {
        while (reader.read())
        {
            // Get the value of the result set
            String ProductName = reader.getValue(1, Product.class);
            int UnitsAvailable = reader.getValue(2, Integer.class);
        }
    }
    else
    {
        // Null query result set retrieved
    }
}
catch (OperationFailedException ex)
{
    if (ex.getErrorCode() == NCacheErrorCodes.INCORRECT_FORMAT) {
        // Make sure the query format is correct
    }
    else
    {
        // Exception can occur due to:
        // Connection Failures
        // Operation Timeout
        // Operation performed during state transfer
    }

}
catch (Exception ex)
{
    // Any generic exception like IllegalArgumentException or NullPointerException
}

// This is an async method
try
{
    // Pre-condition: Cache is already connected
    // Items are already present in the cache
    // Specify the query with the specified criteria
    // Use the Fully Qualified Name (FQN) of your own custom class
    var query = "SELECT productName, UnitsInStock From FQN.Product WHERE UnitsInStock IN (?,?,?,?)";

    // Use QueryCommand for query execution
    var queryCommand = new ncache.QueryCommand(query);
    //Adding Parameters
    let units = [10, 15, 20, 25];
    let parameter = new Map();
    parameter.set("UnitsInStock", units);
    queryCommand.setParameters(parameter);

    // Executing QueryCommand through CacheReader
    var searchService = await this.cache.getSearchService();
    var reader = await searchService.executeReader(queryCommand);

    // Check if result set is not empty
    if (reader.getFieldCount() > 0)
    {
        while (reader.read())
        {
            // Get the value of the result set
            var ProductName = reader.getValue(1, Number());
            var UnitsAvailable = reader.getValue(2, Number());
        }
    }
     else
     {
        // Null query result set retrieved
    }
}
catch (error)
{
    // Handle errors
}

try:
    # Pre-condition: Cache is already connected
    # Items are already present in the cache

    # Create a query which will be executed on the data set
    query = "SELECT product_name, units_in_stock From FQN.Product WHERE units_in_stock IN (10,15,20,25)"

    # Use QueryCommand for query execution
    query_command = ncache.QueryCommand(query)

    # Executing query command through CacheReader
    search_service = cache.get_search_service()
    reader = search_service.execute_reader(query_command)

    # Check if result set is not empty
    if reader.get_field_count() > 0:
        while reader.read():
            product_name = reader.get_value(str, 1)
            units_available = reader.get_value(int, 2)
            # Perform operations
            print("Name: " + str(product_name))
            print("Units: " + str(units_available))
    else:
        # None query results retrieved
        print("Query result is None")
except Exception as exp:
    # Handle errors

try {
    // Pre-condition: Cache is already connected// Pre-condition: Cache is already connected

    // Items are already present in the cache
    // Specify the query with the specified criteria
    // Use the Fully Qualified Name (FQN) of your own custom class
    val query = "SELECT productName, UnitsInStock From FQN.Product WHERE UnitsInStock IN (10,15,20,25)"

    // Use QueryCommand for query execution
    val queryCommand = new QueryCommand(query)

    // Executing QueryCommand through CacheReader
    val reader = cache.getSearchService.executeReader(queryCommand)

    // Check if result set is not empty
    if (reader.getFieldCount > 0) while (reader.read) {
      // Get the value of the result set
      val ProductName = reader.getValue(1, classOf[String])
      val UnitsAvailable = reader.getValue(2, classOf[Int])
    }
    else {
      // Null query result set retrieved
    }
}
catch {
    case exception: Exception => {
      // Handle any errors
    }
}

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 sample application for SQL Searching on GitHub.

SQL IN Operator: Syntax and Usage

Note

Prerequisites

Syntax

Note

Additional Resources

See Also