IRelationalCommand.ExecuteScalarAsync 方法
定义
重要
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重载
ExecuteScalarAsync(RelationalCommandParameterObject, CancellationToken)
使用单个标量结果异步执行命令。
public System.Threading.Tasks.Task<object> ExecuteScalarAsync (Microsoft.EntityFrameworkCore.Storage.RelationalCommandParameterObject parameterObject, System.Threading.CancellationToken cancellationToken = default);public System.Threading.Tasks.Task<object?> ExecuteScalarAsync (Microsoft.EntityFrameworkCore.Storage.RelationalCommandParameterObject parameterObject, System.Threading.CancellationToken cancellationToken = default);abstract member ExecuteScalarAsync : Microsoft.EntityFrameworkCore.Storage.RelationalCommandParameterObject * System.Threading.CancellationToken -> System.Threading.Tasks.Task<obj>Public Function ExecuteScalarAsync (parameterObject As RelationalCommandParameterObject, Optional cancellationToken As CancellationToken = Nothing) As Task(Of Object)参数
- parameterObject
- RelationalCommandParameterObject
此方法的参数。
- cancellationToken
- CancellationToken
等待 CancellationToken 任务完成时要观察的 。
返回
表示异步操作的任务。 任务结果包含命令的结果。
例外
适用于
ExecuteScalarAsync(IRelationalConnection, IReadOnlyDictionary<String,Object>, CancellationToken)
使用单个标量结果异步执行命令。
public System.Threading.Tasks.Task<object> ExecuteScalarAsync (Microsoft.EntityFrameworkCore.Storage.IRelationalConnection connection, System.Collections.Generic.IReadOnlyDictionary<string,object> parameterValues, System.Threading.CancellationToken cancellationToken = default);abstract member ExecuteScalarAsync : Microsoft.EntityFrameworkCore.Storage.IRelationalConnection * System.Collections.Generic.IReadOnlyDictionary<string, obj> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<obj>Public Function ExecuteScalarAsync (connection As IRelationalConnection, parameterValues As IReadOnlyDictionary(Of String, Object), Optional cancellationToken As CancellationToken = Nothing) As Task(Of Object)参数
- connection
- IRelationalConnection
要对其执行的连接。
- parameterValues
- IReadOnlyDictionary<String,Object>
参数的值。
- cancellationToken
- CancellationToken
等待 CancellationToken 任务完成时要观察的 。
返回
表示异步操作的任务。 任务结果包含命令的结果。
适用于
ExecuteScalarAsync(IRelationalConnection, IReadOnlyDictionary<String,Object>, Boolean, CancellationToken)
注意
Use overload without 'manageConnection' parameter
使用单个标量结果异步执行命令。
public System.Threading.Tasks.Task<object> ExecuteScalarAsync (Microsoft.EntityFrameworkCore.Storage.IRelationalConnection connection, System.Collections.Generic.IReadOnlyDictionary<string,object> parameterValues = default, bool manageConnection = true, System.Threading.CancellationToken cancellationToken = default);[System.Obsolete("Use overload without 'manageConnection' parameter")]
public System.Threading.Tasks.Task<object> ExecuteScalarAsync (Microsoft.EntityFrameworkCore.Storage.IRelationalConnection connection, System.Collections.Generic.IReadOnlyDictionary<string,object> parameterValues, bool manageConnection, System.Threading.CancellationToken cancellationToken = default);abstract member ExecuteScalarAsync : Microsoft.EntityFrameworkCore.Storage.IRelationalConnection * System.Collections.Generic.IReadOnlyDictionary<string, obj> * bool * System.Threading.CancellationToken -> System.Threading.Tasks.Task<obj>[<System.Obsolete("Use overload without 'manageConnection' parameter")>]
abstract member ExecuteScalarAsync : Microsoft.EntityFrameworkCore.Storage.IRelationalConnection * System.Collections.Generic.IReadOnlyDictionary<string, obj> * bool * System.Threading.CancellationToken -> System.Threading.Tasks.Task<obj>Public Function ExecuteScalarAsync (connection As IRelationalConnection, Optional parameterValues As IReadOnlyDictionary(Of String, Object) = Nothing, Optional manageConnection As Boolean = true, Optional cancellationToken As CancellationToken = Nothing) As Task(Of Object)Public Function ExecuteScalarAsync (connection As IRelationalConnection, parameterValues As IReadOnlyDictionary(Of String, Object), manageConnection As Boolean, Optional cancellationToken As CancellationToken = Nothing) As Task(Of Object)参数
- connection
- IRelationalConnection
要对其执行的连接。
- parameterValues
- IReadOnlyDictionary<String,Object>
参数的值。
- manageConnection
- Boolean
一个 值，该值指示是否根据需要打开和关闭连接。
- cancellationToken
- CancellationToken
等待 CancellationToken 任务完成时要观察的 。
返回
表示异步操作的任务。 任务结果包含命令的结果。
- 属性
