public virtual Expression Translate(MethodCallExpression methodCallExpression)
{
if (Equals(methodCallExpression.Method, _methodInfo))
{
var patternExpression = methodCallExpression.Arguments[0];
var endsWithExpression = new NullCompensatedExpression(
Expression.Equal(
new SqlFunctionExpression(
"SUBSTR",
// ReSharper disable once PossibleNullReferenceException
methodCallExpression.Object.Type,
new[]
{
methodCallExpression.Object,
Expression.Negate(
new SqlFunctionExpression("LENGTH", typeof(int), new[] { patternExpression }))
}),
patternExpression));
return(patternExpression is ConstantExpression patternConstantExpression
? (string)patternConstantExpression.Value == string.Empty
? (Expression)Expression.Constant(true)
: endsWithExpression
: Expression.OrElse(
endsWithExpression,
Expression.Equal(patternExpression, Expression.Constant(string.Empty))));
}
return(null);
}
/// <summary>
/// 转换
/// </summary>
/// <param name="methodCallExpression">方法调用表达式</param>
/// <returns></returns>
public virtual Expression Translate(MethodCallExpression methodCallExpression)
{
if (object.Equals(methodCallExpression.Method, _methodInfo))
{
Expression expression = methodCallExpression.Arguments[0];
NullCompensatedExpression nullCompensatedExpression = new NullCompensatedExpression(Expression.Equal(new SqlFunctionExpression("SUBSTR", methodCallExpression.Object.Type, new Expression[2]
{
methodCallExpression.Object,
Expression.Negate(new SqlFunctionExpression("LENGTH", typeof(int), new Expression[1]
{
expression
}))
}), expression));
ConstantExpression constantExpression;
if ((constantExpression = (expression as ConstantExpression)) == null)
{
return(Expression.OrElse(nullCompensatedExpression, Expression.Equal(expression, Expression.Constant(string.Empty))));
}
string obj = (string)constantExpression.Value;
if (obj == null || obj.Length != 0)
{
return(nullCompensatedExpression);
}
return(Expression.Constant(true));
}
return(null);
}
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
public virtual Expression Translate(
MethodCallExpression methodCallExpression,
IDiagnosticsLogger <DbLoggerCategory.Query> logger)
{
if (Equals(methodCallExpression.Method, _methodInfo))
{
var patternExpression = methodCallExpression.Arguments[0];
var endsWithExpression = new NullCompensatedExpression(
Expression.Equal(
new SqlFunctionExpression(
"RIGHT",
// ReSharper disable once PossibleNullReferenceException
methodCallExpression.Object.Type,
new[] { methodCallExpression.Object, new SqlFunctionExpression("LEN", typeof(int), new[] { patternExpression }) }),
patternExpression));
return(patternExpression is ConstantExpression patternConstantExpression
? ((string)patternConstantExpression.Value)?.Length == 0
? (Expression)Expression.Constant(true)
: endsWithExpression
: Expression.OrElse(
endsWithExpression,
Expression.Equal(patternExpression, Expression.Constant(string.Empty))));
}
return(null);
}
/// <summary>
/// This is an internal API that supports the Entity Framework Core infrastructure and not subject to
/// the same compatibility standards as public APIs. It may be changed or removed without notice in
/// any release. You should only use it directly in your code with extreme caution and knowing that
/// doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
protected override Expression VisitExtension(Expression expression)
{
var selectExpression = expression as SelectExpression;
if (selectExpression?.Predicate != null)
{
var predicate = new EqualityPredicateInExpressionOptimizer().Visit(selectExpression.Predicate);
var predicateNegationExpressionOptimizer = new PredicateNegationExpressionOptimizer();
predicate = predicateNegationExpressionOptimizer.Visit(predicate);
predicate = new PredicateReductionExpressionOptimizer().Visit(predicate);
predicate = new EqualityPredicateExpandingVisitor().Visit(predicate);
predicate = predicateNegationExpressionOptimizer.Visit(predicate);
if (_useRelationalNulls)
{
predicate = new NullCompensatedExpression(predicate);
}
selectExpression.Predicate = predicate;
}
else if (expression is PredicateJoinExpressionBase joinExpression)
{
joinExpression.Predicate = new DiscriminatorPredicateOptimizingVisitor().Visit(joinExpression.Predicate);
joinExpression.Predicate = new EqualityPredicateInExpressionOptimizer().Visit(joinExpression.Predicate);
}
return(base.VisitExtension(expression));
}
public virtual Expression Translate(MethodCallExpression methodCallExpression)
{
if (Equals(methodCallExpression.Method, _methodInfo))
{
var patternExpression = methodCallExpression.Arguments[0];
var patternConstantExpression = patternExpression as ConstantExpression;
var endsWithExpression = new NullCompensatedExpression(
Expression.Equal(
new SqlFunctionExpression(
"RIGHT",
methodCallExpression.Object.Type,
new[]
{
methodCallExpression.Object,
new SqlFunctionExpression("CHARACTER_LENGTH", typeof(int), new[] { patternExpression })
}),
patternExpression));
return(patternConstantExpression != null
? (string)patternConstantExpression.Value == string.Empty
? (Expression)Expression.Constant(true)
: endsWithExpression
: Expression.OrElse(
endsWithExpression,
Expression.Equal(patternExpression, Expression.Constant(string.Empty))));
}
return(null);
}
private static Expression MakeEndsWithExpressionImpl(
[NotNull] Expression target,
[NotNull] Expression suffix,
[NotNull] Expression originalSuffix)
{
var endsWithExpression =
new NullCompensatedExpression(Expression.Equal(
new SqlFunctionExpression(
"RIGHT",
target.Type,
new[]
{
target,
CharLength(suffix)
}),
suffix));
if (originalSuffix is ConstantExpression constantSuffix)
{
return((string)constantSuffix.Value == string.Empty
? (Expression)Expression.Constant(true)
: endsWithExpression);
}
else
{
return(Expression.OrElse(
endsWithExpression,
Expression.Equal(originalSuffix, Expression.Constant(string.Empty))));
}
}
