public TEntity GetSingle(string property, object value)
{
var expression = Lambda.Equal <TEntity>(property, value);
var find = GetSingle(expression);
return(find);
}
public TEntity GetSingle(string property, object value)
{
// var dynamicWhere = LinqHelper.GetExpression<TEntity, bool>($"entity.{property} == MongoDB.Bson.ObjectId.Parse(\"{value}\")", "entity");
var expression = Lambda.Equal <TEntity>(property, value);
var find = GetSingle(expression);
return(find);
}
public void TestEqual()
{
Expression <Func <Sample, bool> > expected = t => t.IntValue == 1;
Assert.Equal(expected.ToString(), Lambda.Equal <Sample>("IntValue", 1).ToString());
Expression <Func <Sample, bool> > expected2 = t => t.Test2.IntValue == 1;
Assert.Equal(expected2.ToString(), Lambda.Equal <Sample>("Test2.IntValue", 1).ToString());
}
public void TestEqual()
{
//一级属性
Expression <Func <Test1, bool> > expected = t => t.Age == 1;
Assert.AreEqual(expected.ToString(), Lambda.Equal <Test1>("Age", 1).ToString());
//二级属性
Expression <Func <Test1, bool> > expected2 = t => t.A.Integer == 1;
Assert.AreEqual(expected2.ToString(), Lambda.Equal <Test1>("A.Integer", 1).ToString());
}
/// <summary>
/// 查询表达式,ID的查询
/// </summary>
protected virtual Expression <Func <TEntity, bool> > IdPredicate(object id)
{
return(Lambda.Equal <TEntity>("Id", id));
}
public TEntity GetSingleByIdNoTracking(TKey id)
{
var expression = Lambda.Equal <TEntity>("Id", id);
return(FindAsNoTracking().Where(expression).FirstOrDefault());
}
/// <summary>
/// 构建表达式树
/// 调用：GenerateExpression(new string[]{"username"},new object[]{"zzl"},new string[]{"="});
/// </summary>
/// <typeparam name="T">表类型</typeparam>
/// <param name="keys">字段名</param>
/// <param name="values">字段值</param>
/// <param name="operation">操作符</param>
/// <returns></returns>
public static Expression <Func <T, bool> > GenerateExpression <T>(List <FieldValueParam> listParam)
{
Expression <Func <T, bool> > expression_return = t => true;
try
{
if (listParam.Count > 0)
{
foreach (var item in listParam)
{
switch (item.operation)
{
// 等于
case "=":
expression_return = expression_return.And(Lambda.Equal <T>(item.name, item.value));
break;
// 大于
case ">":
expression_return = expression_return.And(Lambda.Greater <T>(item.name, item.value));
break;
// 大于等于
case ">=":
expression_return = expression_return.And(Lambda.GreaterEqual <T>(item.name, item.value));
break;
// 小于
case "<":
expression_return = expression_return.And(Lambda.Less <T>(item.name, item.value));
break;
// 小于等于
case "<=":
expression_return = expression_return.And(Lambda.LessEqual <T>(item.name, item.value));
break;
// 包含
case "%":
expression_return = expression_return.And(Lambda.Contains <T>(item.name, item.value));
break;
// 包含于
case "in":
string[] arrStr = item.value.ToString().Split(',');
Expression <Func <T, bool> > or_return = t => false;
if (arrStr.Length > 0)
{
foreach (var arr in arrStr)
{
or_return = or_return.Or(Lambda.Contains <T>(item.name, arr));
}
}
expression_return = expression_return.And(or_return);
break;
// 不等于
case "!=":
expression_return = expression_return.And(Lambda.NotEqual <T>(item.name, item.value));
break;
default:
throw new ArgumentException("无效的操作符，目前只支持=,%,>,<,>=,<=,in");
}
}
}
}
catch (Exception ex)
{
throw ex;
}
return(expression_return);
}
