共用方式為

RelationalQueryableMethodTranslatingExpressionVisitor.TranslateFirstOrDefault 方法

  • 參考

定義

命名空間:
Microsoft.EntityFrameworkCore.Query
組件:
Microsoft.EntityFrameworkCore.Relational.dll
套件:
Microsoft.EntityFrameworkCore.Relational v3.0.0
套件:
Microsoft.EntityFrameworkCore.Relational v3.1.0
套件:
Microsoft.EntityFrameworkCore.Relational v5.0.0
套件:
Microsoft.EntityFrameworkCore.Relational v6.0.0
套件:
Microsoft.EntityFrameworkCore.Relational v7.0.0
套件:
Microsoft.EntityFrameworkCore.Relational v8.0.0

First<TSource>(IQueryable<TSource>)在指定的來源上轉譯方法或其 FirstOrDefault<TSource>(IQueryable<TSource>) 其他多載。

protected override Microsoft.EntityFrameworkCore.Query.ShapedQueryExpression TranslateFirstOrDefault (Microsoft.EntityFrameworkCore.Query.ShapedQueryExpression source, System.Linq.Expressions.LambdaExpression predicate, Type returnType, bool returnDefault);
protected override Microsoft.EntityFrameworkCore.Query.ShapedQueryExpression? TranslateFirstOrDefault (Microsoft.EntityFrameworkCore.Query.ShapedQueryExpression source, System.Linq.Expressions.LambdaExpression? predicate, Type returnType, bool returnDefault);
override this.TranslateFirstOrDefault : Microsoft.EntityFrameworkCore.Query.ShapedQueryExpression * System.Linq.Expressions.LambdaExpression * Type * bool -> Microsoft.EntityFrameworkCore.Query.ShapedQueryExpression
Protected Overrides Function TranslateFirstOrDefault (source As ShapedQueryExpression, predicate As LambdaExpression, returnType As Type, returnDefault As Boolean) As ShapedQueryExpression

參數

source
ShapedQueryExpression

套用運算子的成形查詢。

predicate
LambdaExpression

呼叫中提供的述詞。

returnType
Type

結果的傳回型別。

returnDefault
Boolean

值，指出是否應該傳回或擲回預設值。

傳回

ShapedQueryExpression

翻譯後的成形查詢。

適用於