/// <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6
string format = "yyyy-MM-dd HH:mm:ss.ffffff";
if (NpgUtils.IsDateTimeOffset(dbType))
{
string s = string.Empty;
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 6 ? 6 : 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("'{0}{1}'::TIMESTAMPTZ ", myDateTime, myOffset);
return(result);
// Npgsql 的显示都是以本地时区显示的？###
}
/// <summary>
/// 获取 DatetTime 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 GetSqlValueOfDateTime(object value, object dbType, int?scale)
{
// 默认精度6
string format = "yyyy-MM-dd HH:mm:ss.ffffff";
if (NpgUtils.IsDate(dbType))
{
format = "yyyy-MM-dd";
}
else if (NpgUtils.IsDateTime(dbType) || NpgUtils.IsDateTime2(dbType))
{
string s = string.Empty;
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 6 ? 6 : scale.Value, 'f');
}
if (!string.IsNullOrEmpty(s))
{
format = string.Format("yyyy-MM-dd HH:mm:ss.{0}", s);
}
}
string date = ((DateTime)value).ToString(format);
string result = string.Format("'{0}'::TIMESTAMP", date);
return(result);
}
/// <summary>
/// 访问 EndWidth 方法
/// </summary>
/// <param name="m">方法表达式</param>
protected override Expression VisitEndsWith(MethodCallExpression m)
{
if (m != null)
{
_visitor.Visit(m.Object);
if (this.NotOperands != null && this.NotOperands.Contains(m))
{
_builder.Append(" NOT");
}
_builder.Append(" LIKE ");
if (m.Arguments[0].CanEvaluate())
{
ColumnAttribute column = null;
bool isUnicode = NpgUtils.IsUnicode(_visitedMark.Current, out column);
string value = _constor.GetSqlValue(m.Arguments[0].Evaluate().Value, _builder.TranslateContext, column);
if (!_builder.Parameterized && value != null)
{
value = value.TrimStart('N').Trim('\'');
}
if (_builder.Parameterized)
{
_builder.Append("('%' || ");
_builder.Append(value);
_builder.Append(")");
}
else
{
if (isUnicode)
{
_builder.Append('N');
}
_builder.Append("'%");
_builder.Append(value);
_builder.Append("'");
}
}
else
{
_builder.Append("('%' || ");
_visitor.Visit(m.Arguments[0]);
_builder.Append(")");
}
}
return(m);
}
/// <summary>
/// 设置命令参数对象的 DbType属性
/// </summary>
/// <param name="parameter">命令参数对象</param>
/// <param name="dbType">DbType属性</param>
public static void DbType(this NpgsqlParameter parameter, object dbType)
{
if (dbType != null)
{
if (dbType is DbType)
{
parameter.DbType = (DbType)dbType;
}
else if (dbType is NpgsqlDbType)
{
parameter.NpgsqlDbType = (NpgsqlDbType)dbType;
}
else
{
NpgUtils.ThrowException(dbType);
}
}
}
/// <summary>
/// 是否日期+时间类型
/// </summary>
/// <param name="dbType">DbType属性</param>
public static bool IsDateTime(object dbType)
{
if (dbType == null)
{
return(false);
}
else if (dbType is DbType)
{
return(((DbType)dbType) == System.Data.DbType.DateTime);
}
else if (dbType is NpgsqlDbType)
{
return(((NpgsqlDbType)dbType) == NpgsqlDbType.Timestamp);
}
else
{
return(NpgUtils.ThrowException(dbType));
}
}
/// <summary>
/// 是否日期+时间+精度+时区类型
/// </summary>
/// <param name="dbType">DbType属性</param>
public static bool IsDateTimeOffset(object dbType)
{
#if netcore
if (dbType == null)
{
return(false);
}
else if (dbType is DbType)
{
return(((DbType)dbType) == System.Data.DbType.DateTimeOffset);
}
else if (dbType is NpgsqlDbType)
{
return(((NpgsqlDbType)dbType) == NpgsqlDbType.TimestampTz);
}
else
{
return(NpgUtils.ThrowException(dbType));
}
#endif
#if !netcore
if (dbType == null)
{
return(false);
}
else if (dbType is DbType)
{
return(((DbType)dbType) == System.Data.DbType.DateTimeOffset);
}
else if (dbType is NpgsqlDbType)
{
return(((NpgsqlDbType)dbType) == NpgsqlDbType.TimestampTZ);
}
else
{
return(NpgUtils.ThrowException(dbType));
}
#endif
}
/// <summary>
/// 获取 Time 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 GetSqlValueOfTime(object value, object dbType, int?scale)
{
// 默认精度6
string format = @"hh\:mm\:ss\.ffffff";
if (NpgUtils.IsTime(dbType))
{
string s = string.Empty;
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 6 ? 6 : scale.Value, 'f');
}
if (!string.IsNullOrEmpty(s))
{
format = string.Format(@"hh\:mm\:ss\.{0}", s);
}
}
string date = ((TimeSpan)value).ToString(format);
string result = string.Format("'{0}'::TIME", date);
return(result);
}
/// <summary>
/// 检查字段或属性成员声明的 DbType 是否为 Unicode 数据类型
/// </summary>
/// <param name="m">将要检查的字段或属性成员</param>
/// <param name="column">字段或属性成员显示声明的列特性</param>
/// <returns></returns>
public static bool IsUnicode(MemberVisitedStack.VisitedMember m, out ColumnAttribute column)
{
column = m != null?TypeUtils.GetColumnAttribute(m.Member, m.ReflectedType) : null;
return(NpgUtils.IsUnicode(column == null ? null : column.DbType));
}
/// <summary>
/// 检查字段或属性成员声明的 DbType 是否为 Unicode 数据类型
/// </summary>
/// <param name="m">将要检查的字段或属性成员</param>
/// <returns></returns>
public static bool IsUnicode(MemberVisitedStack.VisitedMember m)
{
ColumnAttribute column = null;
return(NpgUtils.IsUnicode(m, out column));
}
/// <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));
}
// 其它类型转字符串
bool isDate =
node.Type == typeof(TimeSpan) ||
node.Type == typeof(TimeSpan?) ||
node.Type == typeof(DateTime) ||
node.Type == typeof(DateTime?) ||
node.Type == typeof(DateTimeOffset) ||
node.Type == typeof(DateTimeOffset?);
if (isDate)
{
_builder.Append("TO_CHAR(");
_visitor.Visit(node);
string format = string.Empty;
ColumnAttribute c = _visitedMark.Current != null?TypeUtils.GetColumnAttribute(_visitedMark.Current.Member, _visitedMark.Current.ReflectedType) : null;
if (c != null && NpgUtils.IsTime(c.DbType))
{
format = "hh24:mi:ss.us";
}
else if (c != null && NpgUtils.IsDate(c.DbType))
{
format = "yyyy-mm-dd";
}
else if (c != null && (NpgUtils.IsDateTime(c.DbType) || NpgUtils.IsDateTime2(c.DbType)))
{
format = "yyyy-mm-dd hh24:mi:ss.us";
}
else if (c != null && NpgUtils.IsDateTimeOffset(c.DbType))
{
format = "yyyy-mm-dd hh24:mi:ss.us 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(TimeSpan) || node.Type == typeof(TimeSpan?))
{
format = "hh24:mi:ss.us";
}
else if (node.Type == typeof(DateTime) || node.Type == typeof(DateTime?))
{
format = "yyyy-mm-dd hh24:mi:ss.us";
}
else if (node.Type == typeof(DateTimeOffset) || node.Type == typeof(DateTimeOffset?))
{
format = "yyyy-mm-dd hh24:mi:ss.us TZH:TZM";
}
}
if (!string.IsNullOrEmpty(format))
{
_builder.Append(",'");
_builder.Append(format);
_builder.Append("'");
}
_builder.Append(')');
}
else if (node.Type == typeof(byte[]))
{
_builder.Append("ENCODE(");
_visitor.Visit(node);
_builder.Append(",'hex')");
}
else
{
_builder.Append("CAST(");
_visitor.Visit(node);
_builder.Append(" AS VARCHAR)");
}
return(node);
}