RelationalStorageExtensions.ReadAsync Method
Definition
Important
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Overloads
ReadAsync<TResult>(IRelationalStorage, String, CancellationToken)
public static System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<TResult>> ReadAsync<TResult> (this Orleans.SqlUtils.IRelationalStorage storage, string query, System.Threading.CancellationToken cancellationToken = default);static member ReadAsync : Orleans.SqlUtils.IRelationalStorage * string * System.Threading.CancellationToken -> System.Threading.Tasks.Task<seq<'Result>><Extension()>
Public Function ReadAsync(Of TResult) (storage As IRelationalStorage, query As String, Optional cancellationToken As CancellationToken = Nothing) As Task(Of IEnumerable(Of TResult))Type Parameters
- TResult
The type of the result.
Parameters
- storage
- IRelationalStorage
The storage to use.
- query
- String
Executes a given statement. Especially intended to use with SELECT statement, but works with other queries too.
- cancellationToken
- CancellationToken
The cancellation token. Defaults to None.
Returns
Task<IEnumerable<TResult>>
A list of objects as a result of the .
Applies to
ReadAsync<TResult>(IRelationalStorage, String, Func<IDataRecord,TResult>, Action<IDbCommand>)
public static System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<TResult>> ReadAsync<TResult> (this Orleans.SqlUtils.IRelationalStorage storage, string query, Func<System.Data.IDataRecord,TResult> selector, Action<System.Data.IDbCommand> parameterProvider);static member ReadAsync : Orleans.SqlUtils.IRelationalStorage * string * Func<System.Data.IDataRecord, 'Result> * Action<System.Data.IDbCommand> -> System.Threading.Tasks.Task<seq<'Result>><Extension()>
Public Function ReadAsync(Of TResult) (storage As IRelationalStorage, query As String, selector As Func(Of IDataRecord, TResult), parameterProvider As Action(Of IDbCommand)) As Task(Of IEnumerable(Of TResult))Type Parameters
- TResult
Parameters
- storage
- IRelationalStorage
- query
- String
- selector
- Func<IDataRecord,TResult>
- parameterProvider
- Action<IDbCommand>
Returns
Task<IEnumerable<TResult>>
Applies to
ReadAsync<TResult>(IRelationalStorage, String, Object, CancellationToken)
public static System.Threading.Tasks.Task<System.Collections.Generic.IEnumerable<TResult>> ReadAsync<TResult> (this Orleans.SqlUtils.IRelationalStorage storage, string query, object parameters, System.Threading.CancellationToken cancellationToken = default);static member ReadAsync : Orleans.SqlUtils.IRelationalStorage * string * obj * System.Threading.CancellationToken -> System.Threading.Tasks.Task<seq<'Result>><Extension()>
Public Function ReadAsync(Of TResult) (storage As IRelationalStorage, query As String, parameters As Object, Optional cancellationToken As CancellationToken = Nothing) As Task(Of IEnumerable(Of TResult))Type Parameters
- TResult
The type of the result.
Parameters
- storage
- IRelationalStorage
The storage to use.
- query
- String
Executes a given statement. Especially intended to use with SELECT statement, but works with other queries too.
- parameters
- Object
Adds parameters to the query. Parameter names must match those defined in the query.
- cancellationToken
- CancellationToken
The cancellation token. Defaults to None.
Returns
Task<IEnumerable<TResult>>
A list of objects as a result of the .
Examples
This uses reflection to read results and match the parameters.
//This struct holds the return value in this example.
public struct Information
{
public string TABLE_CATALOG { get; set; }
public string TABLE_NAME { get; set; }
}
//Here reflection (<seealso cref="M:Orleans.SqlUtils.DbExtensions.ReflectionParameterProvider``1(System.Data.IDbCommand,``0,System.Collections.Generic.IReadOnlyDictionary{System.String,System.String})"></seealso>)
is used to match parameter names as well as to read back the results (<seealso cref="M:Orleans.SqlUtils.DbExtensions.ReflectionSelector``1(System.Data.IDataRecord)"></seealso>).
var query = "SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @tname;";
IEnumerable<Information> informationData = await db.ReadAsync<Information>(query, new { tname = 200000 });