TableServiceExtensionMethods.AsTableServiceQuery Method
From Storage Client Library NET API
[This topic is part of the Microsoft Azure Storage Client Library 1.7, which has been deprecated. See Storage Client Library for the latest version.]
Converts a query of type DataServiceQuery to a CloudTableQuery object that handles continuation tokens and retries failed calls to the Table service.
Converts a query of type DataServiceQuery to a CloudTableQuery object that handles continuation tokens and retries failed calls to the Table service.
Namespace: Microsoft.WindowsAzure.StorageClient
Assembly: Microsoft.WindowsAzure.StorageClient (in Microsoft.WindowsAzure.StorageClient.dll)
Usage
| Visual Basic |
|---|
Dim query As IQueryable(Of TElement) Dim returnValue As CloudTableQuery(Of TElement) returnValue = TableServiceExtensionMethods.AsTableServiceQuery(query) |
Syntax
| Visual Basic |
|---|
<ExtensionAttribute> _ Public Shared Function AsTableServiceQuery(Of TElement) ( _ query As IQueryable(Of TElement) _ ) As CloudTableQuery(Of TElement) |
| C# |
|---|
[ExtensionAttribute] public static CloudTableQuery<TElement> AsTableServiceQuery<TElement> ( IQueryable<TElement> query ) |
| C++ |
|---|
[ExtensionAttribute] public: generic<typename TElement> static CloudTableQuery<TElement>^ AsTableServiceQuery ( IQueryable<TElement>^ query ) |
| J# |
|---|
| JScript |
|---|
GenericParameters
- TElement
The type of the element.
Parameters
- query
Type: System.Linq.IQueryable
A DataServiceQuery object.
Return Value
Type: Microsoft.WindowsAzure.StorageClient.CloudTableQuery
A CloudTableQuery object.
Example
The following code example queries entities using a simulated LIKE clause.
| C# | Copy Code |
|---|---|
// Get contacts filtered by prefix.
public static List<ContactEntity> GetContactsByPrefix(string prefix)
{
// Get data context.
TableServiceContext context = tableClient.GetDataServiceContext();
CloudTableQuery<ContactEntity> query;
// Query entities to return names beginning with the specified letter.
// Note that because wildcard queries are not supported, it's necessary to perform prefix
// matching by using string comparisons.
if (!String.IsNullOrEmpty(prefix) && Char.IsLetter(prefix[0]))
{
char prefixChar = prefix[0];
int nextCharValue = ((int)prefixChar) + 1;
char nextChar = (char)nextCharValue;
query = context.CreateQuery<ContactEntity>(tableName)
.Where(e => (e.FirstName.CompareTo(prefixChar.ToString().ToUpper()) >= 0
&& e.FirstName.CompareTo(nextChar.ToString().ToUpper()) < 0))
.AsTableServiceQuery<ContactEntity>();
}
else
{
query = context.CreateQuery<ContactEntity>(tableName).AsTableServiceQuery<ContactEntity>();
}
// Populate list of entities from query results.
List<ContactEntity> list = new List<ContactEntity>();
foreach (ContactEntity entity in query)
{
list.Add(entity);
}
return list;
}
// Class to represent the table schema
public class ContactEntity : TableServiceEntity
{
public ContactEntity()
{
}
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public string HomePhone { get; set; }
public string CellPhone { get; set; }
public string StreetAddress { get; set; }
public string City { get; set; }
public string State { get; set; }
public string ZipCode { get; set; }
} | |
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.