Method ExecuteReader

ExecuteReader(String, IDictionary, Boolean, Int32)

Performs search on the Cache based on the query specified. Also you can specify the chunkSize and flag for specifying if you want data with keys.

Declaration
public virtual ICacheReader ExecuteReader(string query, IDictionary values, bool getData, int chunkSize)
Parameters
Type Name Description
System.String query

simple SQL like query syntax to query objects from cache
System.Collections.IDictionary values

The IDictionary of attribute names and values.
System.Boolean getData

Flag to receive the values/data along with keys
System.Int32 chunkSize

Size of data/keys packets received after search, default value is 512 * 1024 kb's
Returns
Type Description
ICacheReader

Returns a cache data reader

Examples

These operators are supported by NCache Queries.

  1. Comparison Operators = , == , != , <> , < , > , <=, >=, IN
  2. Logical Operators AND , OR , NOT
  3. Miscellaneous () , DateTime.Now , DateTime("any date time compatible string")
Cache _cache= NCache.InitializeCache("myCache");

Hashtable values = new Hashtable();
values.Add("ProductName", "Chai");
values.Add("UnitsInStock", 250);

// Instead of Product, specify fully qualified name of your custom class.
string query = "SELECT Product where this.ProductName = ?";

try
 {
    ICacheReader reader = cache.ExecuteReader(query, values, true, 50);
    if (reader.FieldCount > 0)
      {
          while (reader.Read())
          {
             object category = reader.GetValue(0);
              //perform operations
          }
      }
    else
      {
         //perform operations
      }
     reader.Close();
 }

catch
 {
 //handle exception
 }

ExecuteReader(String, IDictionary)

Performs search on the Cache based on the query specified.

Declaration
public virtual ICacheReader ExecuteReader(string query, IDictionary values)
Parameters
Type Name Description
System.String query

simple SQL like query syntax to query objects from cache
System.Collections.IDictionary values

The IDictionary of attribute names and values.
Returns
Type Description
ICacheReader

Returns a cache data reader

Examples

These operators are supported by NCache Queries.

  1. Comparison Operators = , == , != , <> , < , > , <=, >=, IN
  2. Logical Operators AND , OR , NOT
  3. Miscellaneous () , DateTime.Now , DateTime("any date time compatible string")
Cache _cache = NCache.InitializeCache("myCache");

Hashtable values = new Hashtable();
values.Add("Name", "Paul Jones");
string query="select Test.Application.Employee where this.Name = ?";
ICacheReader reader=_cache.ExecuteReader(query,values);

values.Clear();
values.Add("Salary", 2000);
query="select Test.Application.Employee where this.Salary > ?";
result=_cache.ExecuteReader(query,values);

values.Clear();
values.Add("Name", "Paul jones");
values.Add("Salary", 2000);
query="select Test.Application.Employee where this.Name = ? and this.Salary > ?";
result=_cache.ExecuteReader(query,values);

values.Clear();
values.Add("Name", "Paul Jones");
values.Add("Salary", 2000);
query="select Test.Application.Employee where Not(this.Name = 'Paul Jones' and this.Salary > 2000)";
reader=_cache.ExecuteReader(query,values);
if (reader.FieldCount > 0)
    {
     while (reader.Read())
        {
          object category = reader.GetValue(0);
          //perform operations
        }
    }
else
   {
      //perform operations
   }
reader.Close();

ExecuteReader(String, IDictionary, Boolean)

Performs search on the Cache based on the query specified. Also getData flag can be set that specifies if you want to receive values with keys.

Declaration
public virtual ICacheReader ExecuteReader(string query, IDictionary values, bool getData)
Parameters
Type Name Description
System.String query

simple SQL like query syntax to query objects from cache
System.Collections.IDictionary values

The IDictionary of attribute names and values.
System.Boolean getData

Flag to receive the values/data along with keys
Returns
Type Description
ICacheReader

Returns a cache data reader

Examples

These operators are supported by NCache Queries.

  1. Comparison Operators = , == , != , <> , < , > , <=, >=, IN
  2. Logical Operators AND , OR , NOT
  3. Miscellaneous () , DateTime.Now , DateTime("any date time compatible string")
Cache _cache= NCache.InitializeCache("myCache");

product1 = new Product(3, "Tunnbr?d", "", 4, 2);
product2 = new Product(4, "Tunnbr?d", "", 5, 9);

_cache.Add("2202", product1);
_cache.Add("2203", product2);

string query="SELECT Product  WHERE this.ProductName = ? and this.UnitsInStock > ?";
Hashtable values = new Hashtable();
values.Add("ProductName", "Chai");
values.Add("UnitsInStock", 250);
try
 {
    ICacheReader reader = cache.ExecuteReader(query, values, true);
    if (reader.FieldCount > 0)
      {
          while (reader.Read())
          {
             object category = reader.GetValue(0);
              //perform operations
          }
      }
    else
      {
         //perform operations
      }
     reader.Close();
 }
catch
 {
 //handle exception
 }