/// <summary>
/// 获取实体的列特性
/// </summary>
/// <returns></returns>
public static List <EntityPropColumnAttributes> GetEntityColumnAtrributes <TEntity>() where TEntity : new()
{
List <EntityPropColumnAttributes> list = new List <EntityPropColumnAttributes>();
TEntity model = new TEntity();
foreach (PropertyInfo prop in model.GetType().GetProperties())
{
EntityPropColumnAttributes entity = new EntityPropColumnAttributes();
entity.propName = prop.Name;
entity.fieldName = prop.Name;
entity.isPrimaryKey = false;
entity.isDbGenerated = false;
Type type = Nullable.GetUnderlyingType(prop.PropertyType) ?? prop.PropertyType;
entity.typeName = type.FullName;
object[] CustomAttributesArr = prop.GetCustomAttributes(typeof(ColumnAttribute), false);
if (CustomAttributesArr.Count() > 0)
{
foreach (var obj in CustomAttributesArr)
{
ColumnAttribute attr = obj as ColumnAttribute;
entity.fieldName = attr.Name == null ? prop.Name : attr.Name;
entity.isPrimaryKey = attr.IsPrimaryKey;
entity.isDbGenerated = attr.IsDbGenerated;
}
}
list.Add(entity);
}
return(list);
}
/// <summary>
/// 二元运算符表达式
/// </summary>
/// <param name="left"></param>
/// <param name="right"></param>
/// <param name="type"></param>
/// <returns></returns>
string BinarExpressionProvider(System.Linq.Expressions.Expression left, System.Linq.Expressions.Expression right, System.Linq.Expressions.ExpressionType type)
{
string where = "(";
//先处理左边
string leftStr = ExpressionRouter(left);
//获取实体列的特性
List <EntityPropColumnAttributes> columnAttrList = AttributeHelper.GetEntityColumnAtrributes <TEntity>();
var list = columnAttrList.Where(w => w.propName == leftStr);
if (list.Count() > 0)
{
EntityPropColumnAttributes columnAttribute = list.First();
leftStr = columnAttribute.fieldName;
}
//节点类型
string typeStr = ExpressionTypeCast(type);
//再处理右边
string rightStr = RightExpressionRouter(right).ToStr();
where += leftStr;
where += typeStr;
if (rightStr == "null")
{
if (where.EndsWith(" ="))
{
where = where.Substring(0, where.Length - 2) + " is null";
}
else if (where.EndsWith("<>"))
{
where = where.Substring(0, where.Length - 2) + " is not null";
}
}
else
{
//如果左侧包含（则代表左侧非字段
if (leftStr.Contains("("))
{
where += rightStr;
}
else
{
int num = random.Next(100, 999);
where += "@" + leftStr + num;
listPara.Add(new SqlParameter("@" + leftStr + num, rightStr));
}
}
return(where += ")");
}
string MethodExpression(System.Linq.Expressions.Expression exp)
{
System.Linq.Expressions.MethodCallExpression mce = (System.Linq.Expressions.MethodCallExpression)exp;
string key = ExpressionRouter(mce.Arguments[0]);
object obj = RightExpressionRouter(mce.Arguments[1]);
//对象属性
EntityPropColumnAttributes columnAttribute = columnAttrList.Where(w => w.propName == key).First();
key = columnAttribute.fieldName;
//参数名称
string paramName = "@" + key + random.Next(1000, 9999);
if (mce.Method.Name == "Like" || mce.Method.Name == "NotLike")
{
listPara.Add(new SqlParameter(paramName, "%" + obj.ToStr() + "%"));
}
string values = "";
#region 拼接参数值
if (mce.Method.Name == "In" || mce.Method.Name == "NotIn")
{
string json = JsonHelper.Serialize(obj);
List <object> list = JsonHelper.Deserialize <List <object> >(json);
if (list.Count == 0)
{
return(" (1=2) ");
}
int index = 0;
foreach (var value in list)
{
index++;
listPara.Add(new SqlParameter(paramName + index, value.ToStr()));
values += paramName + index + ",";
}
}
values = values.TrimEnd(',');
#endregion
if (mce.Method.Name == "Like")
{
return(string.Format("({0} like {1})", key, paramName));
}
else if (mce.Method.Name == "NotLike")
{
return(string.Format("({0} Not like {1})", key, paramName));
}
else if (mce.Method.Name == "In")
{
return(string.Format("{0} In ({1})", key, values));
}
else if (mce.Method.Name == "NotIn")
{
return(string.Format("{0} Not In ({1})", key, values));
}
return(" (1=2) ");
}
