/*====================================================*/
/// <summary>避免 SqlParameter 參數數量超過 2100 個，將查詢 IN 分次執行。</summary>
public static IEnumerable <TSource> WhereIn <TSource, T>(this IQueryable <TSource> source, Expression <Func <TSource, T> > selector, IEnumerable <T> values, int blockSize = 2000)
{
if (values == null || !values.Any())
{
return(Enumerable.Empty <TSource>());
}
MethodInfo containsMethod = LambdaUtils.GetMethod(() => values.Contains(default(T)));
IEnumerable <TSource> result = values
.BulkToList(blockSize)
.SelectMany(valueList =>
{
var containsExpr = Expression.Call(containsMethod, Expression.Constant(valueList), selector.Body);
return(source.Where(Expression.Lambda <Func <TSource, bool> >(containsExpr, selector.Parameters)));
});
return(result);
}
public void GetMethod_RunTest3()
{
MethodInfo method = LambdaUtils.GetMethod(() => new[] { 1 }.Contains(1));
Assert.NotNull(method);
}
public void GetMethod_RunTest2()
{
MethodInfo method = LambdaUtils.GetMethod <IEnumerable <int> >(x => x.Contains(1));
Assert.NotNull(method);
}
public void GetMethod_RunTest()
{
MethodInfo method = LambdaUtils.GetMethod <IEnumerable <int> >(x => x.Any(y => true));
Assert.NotNull(method);
}
/// <summary>尋找 Lambda Expression tree 中的 MethodInfo</summary>
public static MethodInfo GetMethod(this Expression expr)
{
return(LambdaUtils.GetMethod(expr));
}