/// <summary>
/// 查询数据是否存在
/// </summary>
/// <param name="mapping">数据映射表</param>
/// <param name="query">查询表达式</param>
/// <param name="level">安全级别</param>
/// <returns>结果</returns>
internal bool Exists(DataEntityMapping mapping, QueryExpression query, SafeLevel level)
{
bool exists = false;
//Region region = new Region(0, 1);
using (IDbCommand command = _dataBase.Factory.CreateExistsCommand(mapping, query))
{
PrimitiveDataDefine pm = PrimitiveDataDefine.Create(typeof(Int32), 0);
foreach (object obj in QueryDataReader(pm, command, null, level))
{
exists = true;
}
}
return(exists);
}
private static DataDefine TransferDataDefine(DataFieldMapping fieldMapping)
{
DataDefine define = null;
if (fieldMapping is PrimitiveFieldMapping)
{
if (fieldMapping.ObjectType == typeof(string))
{
define = PrimitiveDataDefine.CreateString(fieldMapping.IsNullable, fieldMapping.Name);
}
else
{
if (fieldMapping.IsNullable)
{
Type itemstype = System.Type.GetType("System.Nullable`1");
Type type = itemstype.MakeGenericType(fieldMapping.ObjectType);
define = PrimitiveDataDefine.Create(type, fieldMapping.Name);
}
else
{
define = PrimitiveDataDefine.Create(fieldMapping.ObjectType, fieldMapping.Name);
}
}
}
else
if (fieldMapping is EnumFieldMapping)
{
EnumFieldMapping em = fieldMapping as EnumFieldMapping;
if (fieldMapping.IsNullable)
{
Type itemstype = System.Type.GetType("System.Nullable`1");
Type type = itemstype.MakeGenericType(fieldMapping.ObjectType);
define = EnumDataDefine.Create(type, em.EnumType, fieldMapping.Name);
}
else
{
define = EnumDataDefine.Create(fieldMapping.ObjectType, em.EnumType, fieldMapping.Name);
}
}
else
{
throw new LightDataException(RE.OnlyPrimitiveFieldCanSelectSingle);
}
return(define);
}
private static DataDefine TransferDataDefine(Type dataType, string name, bool isNullable)
{
DataDefine define = null;
if (dataType == typeof(string))
{
define = PrimitiveDataDefine.CreateString(isNullable, name);
}
else
{
if (isNullable)
{
Type itemstype = System.Type.GetType("System.Nullable`1");
Type type = itemstype.MakeGenericType(dataType);
define = PrimitiveDataDefine.Create(type, name);
}
else
{
define = PrimitiveDataDefine.Create(dataType, name);
}
}
return(define);
}
