/// <summary>
/// 获取该类型的默认值
/// </summary>
/// <param name="objType"></param>
/// <returns></returns>
public static TypeItem GetDefaultValue(Type objType)
{
string typeName = objType.FullName;
TypeItem item = null;
_dicDefaultValues.TryGetValue(typeName, out item);
return(item);
}
/// <summary>
/// 把C#类型转换成SQL类型
/// </summary>
/// <param name="valueType"></param>
/// <returns></returns>
public static DbType ToDbType(Type valueType)
{
TypeItem item = GetDefaultValue(valueType);
if (item != null)
{
return(item.DbType);
}
return(DbType.Object);
}
/// <summary>
/// 获取C#类型
/// </summary>
/// <param name="type"></param>
/// <returns></returns>
public static Type GetCSharpVariableType(DbType type)
{
int index = (int)type;
if (index >= 0 && index < dbTypeMapping.Length)
{
TypeItem item = dbTypeMapping[index];
if (item != null)
{
return(item.ItemType);
}
}
return(null);
}
/// <summary>
/// 判断是否默认值
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
public static bool IsDefaultValue(object value)
{
if (value == null)
{
return(true);
}
string typeName = value.GetType().FullName;
TypeItem item = null;
if (_dicDefaultValues.TryGetValue(typeName, out item))
{
return(value.Equals(item.DefaultValue));
}
return(false);
}
private static Dictionary <string, TypeItem> InitDefauleValues()
{
Dictionary <string, TypeItem> ret = new Dictionary <string, TypeItem>();
dbTypeMapping = new TypeItem[28];
TypeItem item;
item = new TypeItem(typeof(DateTime), DefaultValue.DefaultDateTime, DbType.DateTime);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
dbTypeMapping[(int)DbType.Date] = item;
dbTypeMapping[(int)DbType.Time] = item;
dbTypeMapping[26] = item; //DateTime2
dbTypeMapping[27] = item; //DateTimeOffset
item = new TypeItem(typeof(byte[]), null, DbType.Binary);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(System.DBNull), System.DBNull.Value, DbType.Object);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(Guid), DefaultValue.DefaultGuid, DbType.Guid);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(int), DefaultValue.DefaultInt, DbType.Int32);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(double), DefaultValue.DefaultDouble, DbType.Double);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(float), DefaultValue.DefaultFloat, DbType.Single);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(decimal), DefaultValue.DefaultDecimal, DbType.Decimal);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
dbTypeMapping[(int)DbType.Currency] = item;
dbTypeMapping[(int)DbType.VarNumeric] = item;
item = new TypeItem(typeof(sbyte), DefaultValue.DefaultSbyte, DbType.SByte);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(byte), DefaultValue.DefaultSbyte, DbType.Byte);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(short), DefaultValue.DefaultShort, DbType.Int16);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(long), DefaultValue.DefaultLong, DbType.Int64);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
item = new TypeItem(typeof(string), null, DbType.String);
ret.Add(item.ItemType.FullName, item);
dbTypeMapping[(int)item.DbType] = item;
dbTypeMapping[(int)DbType.StringFixedLength] = item;
dbTypeMapping[(int)DbType.AnsiString] = item;
dbTypeMapping[(int)DbType.AnsiStringFixedLength] = item;
return(ret);
}