public virtual SqlExpression Translate(SqlExpression instance, MemberInfo member, Type returnType)
{
Check.NotNull(member, nameof(member));
Check.NotNull(returnType, nameof(returnType));
if (member.DeclaringType == typeof(DateTime))
{
var memberName = member.Name;
if (_datePartMapping.TryGetValue(memberName, out var datePart))
{
return(_sqlExpressionFactory.Convert(
SqliteExpression.Strftime(
_sqlExpressionFactory,
typeof(string),
datePart,
instance),
returnType));
}
if (string.Equals(memberName, nameof(DateTime.Ticks)))
{
return(_sqlExpressionFactory.Convert(
_sqlExpressionFactory.Multiply(
_sqlExpressionFactory.Subtract(
_sqlExpressionFactory.Function(
"julianday",
new[] { instance },
nullable: true,
argumentsPropagateNullability: new[] { true },
typeof(double)),
_sqlExpressionFactory.Constant(1721425.5)), // NB: Result of julianday('0001-01-01 00:00:00')
_sqlExpressionFactory.Constant(TimeSpan.TicksPerDay)),
typeof(long)));
}
if (string.Equals(memberName, nameof(DateTime.Millisecond)))
{
return(_sqlExpressionFactory.Modulo(
_sqlExpressionFactory.Multiply(
_sqlExpressionFactory.Convert(
SqliteExpression.Strftime(
_sqlExpressionFactory,
typeof(string),
"%f",
instance),
typeof(double)),
_sqlExpressionFactory.Constant(1000)),
_sqlExpressionFactory.Constant(1000)));
}
var format = "%Y-%m-%d %H:%M:%f";
SqlExpression timestring;
var modifiers = new List <SqlExpression>();
switch (memberName)
{
case nameof(DateTime.Now):
timestring = _sqlExpressionFactory.Constant("now");
modifiers.Add(_sqlExpressionFactory.Constant("localtime"));
break;
case nameof(DateTime.UtcNow):
timestring = _sqlExpressionFactory.Constant("now");
break;
case nameof(DateTime.Date):
timestring = instance;
modifiers.Add(_sqlExpressionFactory.Constant("start of day"));
break;
case nameof(DateTime.Today):
timestring = _sqlExpressionFactory.Constant("now");
modifiers.Add(_sqlExpressionFactory.Constant("localtime"));
modifiers.Add(_sqlExpressionFactory.Constant("start of day"));
break;
case nameof(DateTime.TimeOfDay):
format = "%H:%M:%f";
timestring = instance;
break;
default:
return(null);
}
Check.DebugAssert(timestring != null, "timestring is null");
return(_sqlExpressionFactory.Function(
"rtrim",
new SqlExpression[]
{
_sqlExpressionFactory.Function(
"rtrim",
new SqlExpression[]
{
SqliteExpression.Strftime(
_sqlExpressionFactory,
returnType,
format,
timestring,
modifiers),
_sqlExpressionFactory.Constant("0")
},
nullable: true,
argumentsPropagateNullability: new[] { true, false },
returnType),
_sqlExpressionFactory.Constant(".")
},
nullable: true,
argumentsPropagateNullability: new[] { true, false },
returnType));
}
return(null);
}