/// <summary>
/// Translates the given method call expression.
/// </summary>
/// <param name="methodCallExpression">The method call expression.</param>
/// <param name="logger"> The logger. </param>
/// <returns>
/// A SQL expression representing the translated MethodCallExpression.
/// </returns>
public virtual Expression Translate(
MethodCallExpression methodCallExpression,
IDiagnosticsLogger <DbLoggerCategory.Query> logger)
{
var method = methodCallExpression.Method;
Expression modifier = null;
if (Equals(method, _addMilliseconds))
{
modifier = Expression.Add(
new ExplicitCastExpression(
Expression.Divide(
methodCallExpression.Arguments[0],
Expression.Convert(
Expression.Constant(1000),
typeof(double))),
typeof(string)),
Expression.Constant(" seconds"),
_concat);
}
else if (Equals(method, _addTicks))
{
modifier = Expression.Add(
new ExplicitCastExpression(
Expression.Divide(
Expression.Convert(
methodCallExpression.Arguments[0],
typeof(double)),
Expression.Constant((double)TimeSpan.TicksPerSecond)),
typeof(string)),
Expression.Constant(" seconds"),
_concat);
}
else if (_methodInfoToUnitSuffix.TryGetValue(method, out var unitSuffix))
{
modifier = Expression.Add(
new ExplicitCastExpression(
methodCallExpression.Arguments[0],
typeof(string)),
Expression.Constant(unitSuffix),
_concat);
}
else
{
return(null);
}
Debug.Assert(modifier != null);
return(new SqlFunctionExpression(
"rtrim",
typeof(DateTime),
new Expression[]
{
new SqlFunctionExpression(
"rtrim",
typeof(DateTime),
new Expression[]
{
SqliteExpression.Strftime(
typeof(DateTime),
"%Y-%m-%d %H:%M:%f",
methodCallExpression.Object,
new[] { modifier }),
Expression.Constant("0")
}),
Expression.Constant(".")
}));
}
/// <summary>
/// This API supports the Entity Framework Core infrastructure and is not intended to be used
/// directly from your code. This API may change or be removed in future releases.
/// </summary>
public virtual Expression Translate(MemberExpression memberExpression)
{
if (memberExpression.Member.DeclaringType != typeof(DateTime))
{
return(null);
}
var memberName = memberExpression.Member.Name;
if (memberName == nameof(DateTime.Millisecond))
{
return(Expression.Modulo(
Expression.Convert(
Expression.Multiply(
new ExplicitCastExpression(
SqliteExpression.Strftime(
typeof(string),
"%f",
memberExpression.Expression),
typeof(double)),
Expression.Convert(
Expression.Constant(1000),
typeof(double))),
typeof(int)),
Expression.Constant(1000)));
}
if (memberName == nameof(DateTime.Ticks))
{
return(new ExplicitCastExpression(
Expression.Multiply(
Expression.Subtract(
new SqlFunctionExpression(
"julianday",
typeof(double),
new[] { memberExpression.Expression }),
Expression.Constant(1721425.5)), // NB: Result of julianday('0001-01-01 00:00:00')
Expression.Convert(
Expression.Constant(TimeSpan.TicksPerDay),
typeof(double))),
typeof(long)));
}
if (_datePartMapping.TryGetValue(memberName, out var datePart))
{
return(new ExplicitCastExpression(
SqliteExpression.Strftime(
typeof(string),
datePart,
memberExpression.Expression),
memberExpression.Type));
}
string format = null;
Expression timestring = null;
var modifiers = new List <Expression>();
var datetimeFormat = "%Y-%m-%d %H:%M:%f";
switch (memberName)
{
case nameof(DateTime.Now):
format = datetimeFormat;
timestring = Expression.Constant("now");
modifiers.Add(Expression.Constant("localtime"));
break;
case nameof(DateTime.UtcNow):
format = datetimeFormat;
timestring = Expression.Constant("now");
break;
case nameof(DateTime.Date):
format = datetimeFormat;
timestring = memberExpression.Expression;
modifiers.Add(Expression.Constant("start of day"));
break;
case nameof(DateTime.Today):
format = datetimeFormat;
timestring = Expression.Constant("now");
modifiers.Add(Expression.Constant("localtime"));
modifiers.Add(Expression.Constant("start of day"));
break;
case nameof(DateTime.TimeOfDay):
format = "%H:%M:%f";
timestring = memberExpression.Expression;
break;
default:
return(null);
}
Debug.Assert(format != null);
Debug.Assert(timestring != null);
return(new SqlFunctionExpression(
"rtrim",
memberExpression.Type,
new Expression[]
{
new SqlFunctionExpression(
"rtrim",
memberExpression.Type,
new Expression[]
{
SqliteExpression.Strftime(
memberExpression.Type,
format,
timestring,
modifiers),
Expression.Constant("0")
}),
Expression.Constant(".")
}));
}