internal override SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
c.Expression = this.VisitExpression(c.Expression);
for (int i = 0, n = c.Whens.Count; i < n; i++)
{
// Don't walk down the match side. This can't be a column.
c.Whens[i].Value = this.VisitExpression(c.Whens[i].Value);
}
return(c);
}
internal virtual SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
c.Expression = this.VisitExpression(c.Expression);
for (int i = 0, n = c.Whens.Count; i < n; i++)
{
SqlWhen when = c.Whens[i];
when.Match = this.VisitExpression(when.Match);
when.Value = this.VisitExpression(when.Value);
}
return(c);
}
internal bool AreCaseWhenValuesConstant(SqlSimpleCase sc)
{
foreach (SqlWhen when in sc.Whens)
{
if (when.Value.NodeType != SqlNodeType.Value)
{
return(false);
}
}
return(true);
}
internal override SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
SqlExpression expr = this.VisitExpression(c.Expression);
SqlWhen[] whens = new SqlWhen[c.Whens.Count];
for (int i = 0, n = whens.Length; i < n; i++)
{
SqlWhen when = c.Whens[i];
whens[i] = new SqlWhen(this.VisitExpression(when.Match), this.VisitExpression(when.Value));
}
return(new SqlSimpleCase(c.ClrType, expr, whens, c.SourceExpression));
}
internal override SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
bool saveCanJoin = this.canJoin;
this.canJoin = false;
try {
return(base.VisitSimpleCase(c));
}
finally {
this.canJoin = saveCanJoin;
}
}
internal override SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
SqlExpression expr = VisitExpression(c.Expression);
var array = new SqlWhen[c.Whens.Count];
var i = 0;
for (var num = array.Length; i < num; i++)
{
var sqlWhen = c.Whens[i];
array[i] = new SqlWhen(VisitExpression(sqlWhen.Match), VisitExpression(sqlWhen.Value));
}
return(new SqlSimpleCase(c.ClrType, expr, array, c.SourceExpression));
}
private static SqlExpression UnwrapTrivialCaseExpression(SqlSimpleCase sc)
{
if (sc.Whens.Count != 1)
{
return(sc);
}
if (!SqlComparer.AreEqual(sc.Expression, sc.Whens[0].Match))
{
return(sc);
}
SqlExpression result = sc.Whens[0].Value;
if (result.NodeType == SqlNodeType.SimpleCase)
{
return(UnwrapTrivialCaseExpression((SqlSimpleCase)result));
}
return(result);
}
/// <summary>
/// Helper for VisitBinaryOperator. Builds the new case with distributed valueds.
/// </summary>
private SqlExpression DistributeOperatorIntoCase(SqlNodeType nt, SqlSimpleCase sc, SqlExpression expr)
{
if (nt != SqlNodeType.EQ && nt != SqlNodeType.NE && nt != SqlNodeType.EQ2V && nt != SqlNodeType.NE2V)
{
throw Error.ArgumentOutOfRange("nt");
}
object val = Eval(expr);
List <SqlExpression> values = new List <SqlExpression>();
List <SqlExpression> matches = new List <SqlExpression>();
foreach (SqlWhen when in sc.Whens)
{
matches.Add(when.Match);
object whenVal = Eval(when.Value);
bool eq = when.Value.SqlType.AreValuesEqual(whenVal, val);
values.Add(sql.ValueFromObject((nt == SqlNodeType.EQ || nt == SqlNodeType.EQ2V) == eq, false, sc.SourceExpression));
}
return(this.VisitExpression(sql.Case(typeof(bool), sc.Expression, matches, values, sc.SourceExpression)));
}
internal override SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
base.VisitSimpleCase(c);
// determine the best common type for all the when values
ProviderType type = c.Whens[0].Value.SqlType;
for (int i = 1; i < c.Whens.Count; i++)
{
ProviderType whenType = c.Whens[i].Value.SqlType;
type = typeProvider.GetBestType(type, whenType);
}
// coerce each one
foreach (SqlWhen when in c.Whens.Where(w => w.Value.SqlType != type && !w.Value.SqlType.IsRuntimeOnlyType))
{
when.Value = sql.UnaryConvert(when.Value.ClrType, type, when.Value, when.Value.SourceExpression);
}
return(c);
}
internal static bool?CanBeNull(SqlExpression expr)
{
switch (expr.NodeType)
{
case SqlNodeType.ExprSet:
SqlExprSet exprSet = (SqlExprSet)expr;
return(CanBeNull(exprSet.Expressions));
case SqlNodeType.SimpleCase:
SqlSimpleCase sc = (SqlSimpleCase)expr;
return(CanBeNull(sc.Whens.Select(w => w.Value)));
case SqlNodeType.Column:
SqlColumn col = (SqlColumn)expr;
if (col.MetaMember != null)
{
return(col.MetaMember.CanBeNull);
}
else if (col.Expression != null)
{
return(CanBeNull(col.Expression));
}
return(null); // Don't know.
case SqlNodeType.ColumnRef:
SqlColumnRef cref = (SqlColumnRef)expr;
return(CanBeNull(cref.Column));
case SqlNodeType.Value:
return(((SqlValue)expr).Value == null);
case SqlNodeType.New:
case SqlNodeType.Multiset:
case SqlNodeType.Grouping:
case SqlNodeType.DiscriminatedType:
case SqlNodeType.IsNotNull: // IsNull\IsNotNull always return true or false and can never return NULL.
case SqlNodeType.IsNull:
case SqlNodeType.Exists:
return(false);
case SqlNodeType.Add:
case SqlNodeType.Sub:
case SqlNodeType.Mul:
case SqlNodeType.Div:
case SqlNodeType.Mod:
case SqlNodeType.BitAnd:
case SqlNodeType.BitOr:
case SqlNodeType.BitXor:
case SqlNodeType.Concat: {
SqlBinary bop = (SqlBinary)expr;
bool? left = CanBeNull(bop.Left);
bool? right = CanBeNull(bop.Right);
return((left != false) || (right != false));
}
case SqlNodeType.Negate:
case SqlNodeType.BitNot: {
SqlUnary uop = (SqlUnary)expr;
return(CanBeNull(uop.Operand));
}
case SqlNodeType.Lift: {
SqlLift lift = (SqlLift)expr;
return(CanBeNull(lift.Expression));
}
case SqlNodeType.OuterJoinedValue:
return(true);
default:
return(null); // Don't know.
}
}
internal override SqlExpression VisitSimpleCase(SqlSimpleCase c)
{
c.Expression = this.VisitExpression(c.Expression);
int compareWhen = 0;
// Find the ELSE if it exists.
for (int i = 0, n = c.Whens.Count; i < n; i++)
{
if (c.Whens[i].Match == null)
{
compareWhen = i;
break;
}
}
c.Whens[compareWhen].Match = VisitExpression(c.Whens[compareWhen].Match);
c.Whens[compareWhen].Value = VisitExpression(c.Whens[compareWhen].Value);
// Compare each other when value to the compare when
List <SqlWhen> newWhens = new List <SqlWhen>();
bool allValuesLiteral = true;
for (int i = 0, n = c.Whens.Count; i < n; i++)
{
if (compareWhen != i)
{
SqlWhen when = c.Whens[i];
when.Match = this.VisitExpression(when.Match);
when.Value = this.VisitExpression(when.Value);
if (!SqlComparer.AreEqual(c.Whens[compareWhen].Value, when.Value))
{
newWhens.Add(when);
}
allValuesLiteral = allValuesLiteral && when.Value.NodeType == SqlNodeType.Value;
}
}
newWhens.Add(c.Whens[compareWhen]);
// Did everything reduce to a single CASE?
SqlExpression rewrite = TryToConsolidateAllValueExpressions(newWhens.Count, c.Whens[compareWhen].Value);
if (rewrite != null)
{
return(rewrite);
}
// Can it be a conjuction (or disjunction) of clauses?
rewrite = TryToWriteAsSimpleBooleanExpression(c.ClrType, c.Expression, newWhens, allValuesLiteral);
if (rewrite != null)
{
return(rewrite);
}
// Can any WHEN clauses be reduced to fall into the ELSE clause?
rewrite = TryToWriteAsReducedCase(c.ClrType, c.Expression, newWhens, c.Whens[compareWhen].Match, c.Whens.Count);
if (rewrite != null)
{
return(rewrite);
}
return(c);
}
internal static bool AreEqual(SqlNode node1, SqlNode node2)
{
if (node1 == node2)
{
return(true);
}
if (node1 == null || node2 == null)
{
return(false);
}
if (node1.NodeType == SqlNodeType.SimpleCase)
{
node1 = UnwrapTrivialCaseExpression((SqlSimpleCase)node1);
}
if (node2.NodeType == SqlNodeType.SimpleCase)
{
node2 = UnwrapTrivialCaseExpression((SqlSimpleCase)node2);
}
if (node1.NodeType != node2.NodeType)
{
// allow expression sets to compare against single expressions
if (node1.NodeType == SqlNodeType.ExprSet)
{
SqlExprSet eset = (SqlExprSet)node1;
for (int i = 0, n = eset.Expressions.Count; i < n; i++)
{
if (AreEqual(eset.Expressions[i], node2))
{
return(true);
}
}
}
else if (node2.NodeType == SqlNodeType.ExprSet)
{
SqlExprSet eset = (SqlExprSet)node2;
for (int i = 0, n = eset.Expressions.Count; i < n; i++)
{
if (AreEqual(node1, eset.Expressions[i]))
{
return(true);
}
}
}
return(false);
}
if (node1.Equals(node2))
{
return(true);
}
switch (node1.NodeType)
{
case SqlNodeType.Not:
case SqlNodeType.Not2V:
case SqlNodeType.Negate:
case SqlNodeType.BitNot:
case SqlNodeType.IsNull:
case SqlNodeType.IsNotNull:
case SqlNodeType.Count:
case SqlNodeType.Max:
case SqlNodeType.Min:
case SqlNodeType.Sum:
case SqlNodeType.Avg:
case SqlNodeType.Stddev:
case SqlNodeType.ValueOf:
case SqlNodeType.OuterJoinedValue:
case SqlNodeType.ClrLength:
return(AreEqual(((SqlUnary)node1).Operand, ((SqlUnary)node2).Operand));
case SqlNodeType.Add:
case SqlNodeType.Sub:
case SqlNodeType.Mul:
case SqlNodeType.Div:
case SqlNodeType.Mod:
case SqlNodeType.BitAnd:
case SqlNodeType.BitOr:
case SqlNodeType.BitXor:
case SqlNodeType.And:
case SqlNodeType.Or:
case SqlNodeType.GE:
case SqlNodeType.GT:
case SqlNodeType.LE:
case SqlNodeType.LT:
case SqlNodeType.EQ:
case SqlNodeType.NE:
case SqlNodeType.EQ2V:
case SqlNodeType.NE2V:
case SqlNodeType.Concat:
SqlBinary firstNode = (SqlBinary)node1;
SqlBinary secondNode = (SqlBinary)node2;
return(AreEqual(firstNode.Left, secondNode.Left) &&
AreEqual(firstNode.Right, secondNode.Right));
case SqlNodeType.Convert:
case SqlNodeType.Treat: {
SqlUnary sun1 = (SqlUnary)node1;
SqlUnary sun2 = (SqlUnary)node2;
return(sun1.ClrType == sun2.ClrType && sun1.SqlType == sun2.SqlType && AreEqual(sun1.Operand, sun2.Operand));
}
case SqlNodeType.Between: {
SqlBetween b1 = (SqlBetween)node1;
SqlBetween b2 = (SqlBetween)node1;
return(AreEqual(b1.Expression, b2.Expression) &&
AreEqual(b1.Start, b2.Start) &&
AreEqual(b1.End, b2.End));
}
case SqlNodeType.Parameter:
return(node1 == node2);
case SqlNodeType.Alias:
return(AreEqual(((SqlAlias)node1).Node, ((SqlAlias)node2).Node));
case SqlNodeType.AliasRef:
return(AreEqual(((SqlAliasRef)node1).Alias, ((SqlAliasRef)node2).Alias));
case SqlNodeType.Column:
SqlColumn col1 = (SqlColumn)node1;
SqlColumn col2 = (SqlColumn)node2;
return(col1 == col2 || (col1.Expression != null && col2.Expression != null && AreEqual(col1.Expression, col2.Expression)));
case SqlNodeType.Table:
return(((SqlTable)node1).MetaTable == ((SqlTable)node2).MetaTable);
case SqlNodeType.Member:
return((((SqlMember)node1).Member == ((SqlMember)node2).Member) &&
AreEqual(((SqlMember)node1).Expression, ((SqlMember)node2).Expression));
case SqlNodeType.ColumnRef:
SqlColumnRef cref1 = (SqlColumnRef)node1;
SqlColumnRef cref2 = (SqlColumnRef)node2;
return(GetBaseColumn(cref1) == GetBaseColumn(cref2));
case SqlNodeType.Value:
return(Object.Equals(((SqlValue)node1).Value, ((SqlValue)node2).Value));
case SqlNodeType.TypeCase: {
SqlTypeCase c1 = (SqlTypeCase)node1;
SqlTypeCase c2 = (SqlTypeCase)node2;
if (!AreEqual(c1.Discriminator, c2.Discriminator))
{
return(false);
}
if (c1.Whens.Count != c2.Whens.Count)
{
return(false);
}
for (int i = 0, c = c1.Whens.Count; i < c; ++i)
{
if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match))
{
return(false);
}
if (!AreEqual(c1.Whens[i].TypeBinding, c2.Whens[i].TypeBinding))
{
return(false);
}
}
return(true);
}
case SqlNodeType.SearchedCase: {
SqlSearchedCase c1 = (SqlSearchedCase)node1;
SqlSearchedCase c2 = (SqlSearchedCase)node2;
if (c1.Whens.Count != c2.Whens.Count)
{
return(false);
}
for (int i = 0, n = c1.Whens.Count; i < n; i++)
{
if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match) ||
!AreEqual(c1.Whens[i].Value, c2.Whens[i].Value))
{
return(false);
}
}
return(AreEqual(c1.Else, c2.Else));
}
case SqlNodeType.ClientCase: {
SqlClientCase c1 = (SqlClientCase)node1;
SqlClientCase c2 = (SqlClientCase)node2;
if (c1.Whens.Count != c2.Whens.Count)
{
return(false);
}
for (int i = 0, n = c1.Whens.Count; i < n; i++)
{
if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match) ||
!AreEqual(c1.Whens[i].Value, c2.Whens[i].Value))
{
return(false);
}
}
return(true);
}
case SqlNodeType.DiscriminatedType: {
SqlDiscriminatedType dt1 = (SqlDiscriminatedType)node1;
SqlDiscriminatedType dt2 = (SqlDiscriminatedType)node2;
return(AreEqual(dt1.Discriminator, dt2.Discriminator));
}
case SqlNodeType.SimpleCase: {
SqlSimpleCase c1 = (SqlSimpleCase)node1;
SqlSimpleCase c2 = (SqlSimpleCase)node2;
if (c1.Whens.Count != c2.Whens.Count)
{
return(false);
}
for (int i = 0, n = c1.Whens.Count; i < n; i++)
{
if (!AreEqual(c1.Whens[i].Match, c2.Whens[i].Match) ||
!AreEqual(c1.Whens[i].Value, c2.Whens[i].Value))
{
return(false);
}
}
return(true);
}
case SqlNodeType.Like: {
SqlLike like1 = (SqlLike)node1;
SqlLike like2 = (SqlLike)node2;
return(AreEqual(like1.Expression, like2.Expression) &&
AreEqual(like1.Pattern, like2.Pattern) &&
AreEqual(like1.Escape, like2.Escape));
}
case SqlNodeType.Variable: {
SqlVariable v1 = (SqlVariable)node1;
SqlVariable v2 = (SqlVariable)node2;
return(v1.Name == v2.Name);
}
case SqlNodeType.FunctionCall: {
SqlFunctionCall f1 = (SqlFunctionCall)node1;
SqlFunctionCall f2 = (SqlFunctionCall)node2;
if (f1.Name != f2.Name)
{
return(false);
}
if (f1.Arguments.Count != f2.Arguments.Count)
{
return(false);
}
for (int i = 0, n = f1.Arguments.Count; i < n; i++)
{
if (!AreEqual(f1.Arguments[i], f2.Arguments[i]))
{
return(false);
}
}
return(true);
}
case SqlNodeType.Link: {
SqlLink l1 = (SqlLink)node1;
SqlLink l2 = (SqlLink)node2;
if (!MetaPosition.AreSameMember(l1.Member.Member, l2.Member.Member))
{
return(false);
}
if (!AreEqual(l1.Expansion, l2.Expansion))
{
return(false);
}
if (l1.KeyExpressions.Count != l2.KeyExpressions.Count)
{
return(false);
}
for (int i = 0, c = l1.KeyExpressions.Count; i < c; ++i)
{
if (!AreEqual(l1.KeyExpressions[i], l2.KeyExpressions[i]))
{
return(false);
}
}
return(true);
}
case SqlNodeType.ExprSet:
SqlExprSet es1 = (SqlExprSet)node1;
SqlExprSet es2 = (SqlExprSet)node2;
if (es1.Expressions.Count != es2.Expressions.Count)
{
return(false);
}
for (int i = 0, n = es1.Expressions.Count; i < n; i++)
{
if (!AreEqual(es1.Expressions[i], es2.Expressions[i]))
{
return(false);
}
}
return(true);
case SqlNodeType.OptionalValue:
SqlOptionalValue ov1 = (SqlOptionalValue)node1;
SqlOptionalValue ov2 = (SqlOptionalValue)node2;
return(AreEqual(ov1.Value, ov2.Value));
case SqlNodeType.Row:
case SqlNodeType.UserQuery:
case SqlNodeType.StoredProcedureCall:
case SqlNodeType.UserRow:
case SqlNodeType.UserColumn:
case SqlNodeType.Multiset:
case SqlNodeType.ScalarSubSelect:
case SqlNodeType.Element:
case SqlNodeType.Exists:
case SqlNodeType.Join:
case SqlNodeType.Select:
case SqlNodeType.New:
case SqlNodeType.ClientQuery:
case SqlNodeType.ClientArray:
case SqlNodeType.Insert:
case SqlNodeType.Update:
case SqlNodeType.Delete:
case SqlNodeType.MemberAssign:
case SqlNodeType.Assign:
case SqlNodeType.Block:
case SqlNodeType.Union:
case SqlNodeType.DoNotVisit:
case SqlNodeType.MethodCall:
case SqlNodeType.Nop:
default:
return(false);
}
}