/// <summary>
/// 获取 DateTimeOffset 类型的 SQL 片断
/// </summary>
/// <param name="value">值</param>
/// <param name="dbType">数据类型</param>
/// <param name="scale">小数位</param>
/// <returns></returns>
protected override string GetSqlValueOfDateTimeOffset(object value, object dbType, int?scale)
{
// 默认精度为6
string format = "yyyy-MM-dd HH:mm:ss.ffffff";
if (OracleUtils.IsDateTimeOffset(dbType))
{
string s = string.Empty;
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 7 ? 7 : scale.Value, 'f');
}
if (!string.IsNullOrEmpty(s))
{
format = string.Format("yyyy-MM-dd HH:mm:ss.{0}", s);
}
}
string myDateTime = ((DateTimeOffset)value).DateTime.ToString(format);
string myOffset = ((DateTimeOffset)value).Offset.ToString(@"hh\:mm");
myOffset = string.Format("{0}{1}", ((DateTimeOffset)value).Offset < TimeSpan.Zero ? '-' : '+', myOffset);
string result = string.Format("TO_TIMESTAMP_TZ('{0} {1}','yyyy-mm-dd hh24:mi:ss.ff tzh:tzm')", myDateTime, myOffset);
return(result);
}
/// <summary>
/// 访问 ToString 方法
/// </summary>
/// <param name="node">即将访问的表达式</param>
protected override Expression VisitToStringImpl(Expression node)
{
// => a.ID.ToString()
// 字符串不进行转换
if (node == null || node.Type == typeof(string))
{
return(_visitor.Visit(node));
}
ColumnAttribute column = null;
bool isUnicode = OracleUtils.IsUnicode(_visitedMark.Current, out column);
bool isBytes = node.Type == typeof(byte[]);
bool isDate = node.Type == typeof(DateTime) ||
node.Type == typeof(DateTime?) ||
node.Type == typeof(TimeSpan) ||
node.Type == typeof(TimeSpan?) ||
node.Type == typeof(DateTimeOffset) ||
node.Type == typeof(DateTimeOffset?);
if (!isBytes)
{
if (isUnicode)
{
_builder.Append("TO_NCHAR(");
}
else
{
_builder.Append("TO_CHAR(");
}
}
// 其它类型转字符串
if (isDate)
{
_visitor.Visit(node);
string format = string.Empty;
ColumnAttribute c = _visitedMark.Current != null?TypeUtils.GetColumnAttribute(_visitedMark.Current.Member, _visitedMark.Current.ReflectedType) : null;
if (c != null && OracleUtils.IsDate(c.DbType))
{
format = "yyyy-mm-dd";
}
else if (c != null && (OracleUtils.IsDateTime(c.DbType) || OracleUtils.IsDateTime2(c.DbType)))
{
format = "yyyy-mm-dd hh24:mi:ss.ff";
}
else if (c != null && OracleUtils.IsDateTimeOffset(c.DbType))
{
format = "yyyy-mm-dd hh24:mi:ss.ff tzh:tzm";
}
// 没有显式指定数据类型，则根据表达式的类型来判断
if (string.IsNullOrEmpty(format))
{
if (node.Type == typeof(DateTime) || node.Type == typeof(DateTime?))
{
format = "yyyy-mm-dd hh24:mi:ss.ff";
}
else if (node.Type == typeof(DateTimeOffset) || node.Type == typeof(DateTimeOffset?))
{
format = "yyyy-mm-dd hh24:mi:ss.ff tzh:tzm";
}
}
if (!string.IsNullOrEmpty(format))
{
_builder.Append(",'");
_builder.Append(format);
_builder.Append("'");
}
}
else if (isBytes)
{
_builder.Append("RTRIM(DBMS_LOB.SUBSTR(");
_visitor.Visit(node);
_builder.Append(')');
}
else if (node.Type == typeof(Guid))
{
_builder.Append("REGEXP_REPLACE(REGEXP_REPLACE(");
_visitor.Visit(node);
_builder.Append(@",'(.{8})(.{4})(.{4})(.{4})(.{12})', '\1-\2-\3-\4-\5'),'(.{2})(.{2})(.{2})(.{2}).(.{2})(.{2}).(.{2})(.{2})(.{18})','\4\3\2\1-\6\5-\8\7\9')");
}
else
{
_visitor.Visit(node);
}
_builder.Append(')');
return(node);
}