Fix 4 parser tests with hex literals, REPLACE transformer, and SAMPLE BY

internal/explain/explain.go

@@ -72,7 +72,7 @@ func Node(sb *strings.Builder, node interface{}, depth int) {
 	case *ast.WithElement:
 		explainWithElement(sb, n, indent, depth)
 	case *ast.Asterisk:
-		explainAsterisk(sb, n, indent)
+		explainAsterisk(sb, n, indent, depth)
 	case *ast.ColumnsMatcher:
 		fmt.Fprintf(sb, "%sColumnsRegexpMatcher\n", indent)
 

internal/explain/expressions.go

@@ -471,12 +471,60 @@ func explainAliasedExpr(sb *strings.Builder, n *ast.AliasedExpr, depth int) {
 	}
 }
 
-func explainAsterisk(sb *strings.Builder, n *ast.Asterisk, indent string) {
+func explainAsterisk(sb *strings.Builder, n *ast.Asterisk, indent string, depth int) {
+	// Check if there are any column transformers (EXCEPT, REPLACE)
+	hasTransformers := len(n.Except) > 0 || len(n.Replace) > 0
+
 	if n.Table != "" {
-		fmt.Fprintf(sb, "%sQualifiedAsterisk (children %d)\n", indent, 1)
-		fmt.Fprintf(sb, "%s Identifier %s\n", indent, n.Table)
+		if hasTransformers {
+			fmt.Fprintf(sb, "%sQualifiedAsterisk (children %d)\n", indent, 2)
+			fmt.Fprintf(sb, "%s Identifier %s\n", indent, n.Table)
+			explainColumnsTransformers(sb, n, indent+" ", depth+1)
+		} else {
+			fmt.Fprintf(sb, "%sQualifiedAsterisk (children %d)\n", indent, 1)
+			fmt.Fprintf(sb, "%s Identifier %s\n", indent, n.Table)
+		}
 	} else {
-		fmt.Fprintf(sb, "%sAsterisk\n", indent)
+		if hasTransformers {
+			fmt.Fprintf(sb, "%sAsterisk (children %d)\n", indent, 1)
+			explainColumnsTransformers(sb, n, indent+" ", depth+1)
+		} else {
+			fmt.Fprintf(sb, "%sAsterisk\n", indent)
+		}
+	}
+}
+
+func explainColumnsTransformers(sb *strings.Builder, n *ast.Asterisk, indent string, depth int) {
+	transformerCount := 0
+	if len(n.Except) > 0 {
+		transformerCount++
+	}
+	if len(n.Replace) > 0 {
+		transformerCount++
+	}
+
+	fmt.Fprintf(sb, "%sColumnsTransformerList (children %d)\n", indent, transformerCount)
+
+	if len(n.Except) > 0 {
+		fmt.Fprintf(sb, "%s ColumnsExceptTransformer (children %d)\n", indent, len(n.Except))
+		for _, col := range n.Except {
+			fmt.Fprintf(sb, "%s  Identifier %s\n", indent, col)
+		}
+	}
+
+	if len(n.Replace) > 0 {
+		fmt.Fprintf(sb, "%s ColumnsReplaceTransformer (children %d)\n", indent, len(n.Replace))
+		for _, replace := range n.Replace {
+			children := 0
+			if replace.Expr != nil {
+				children = 1
+			}
+			fmt.Fprintf(sb, "%s  ColumnsReplaceTransformer::Replacement (children %d)\n", indent, children)
+			if replace.Expr != nil {
+				// Output the expression without alias - the replacement name is implied
+				Node(sb, replace.Expr, depth+3)
+			}
+		}
 	}
 }
 

internal/explain/statements.go

@@ -147,7 +147,7 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 			}
 		}
 	}
-	if n.Engine != nil || len(n.OrderBy) > 0 || len(n.PrimaryKey) > 0 || n.PartitionBy != nil || len(n.Settings) > 0 {
+	if n.Engine != nil || len(n.OrderBy) > 0 || len(n.PrimaryKey) > 0 || n.PartitionBy != nil || n.SampleBy != nil || len(n.Settings) > 0 {
 		storageChildren := 0
 		if n.Engine != nil {
 			storageChildren++
@@ -161,6 +161,25 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 		if len(n.PrimaryKey) > 0 {
 			storageChildren++
 		}
+		// SAMPLE BY is only shown in EXPLAIN AST when it's a function (not a simple identifier)
+		// and when it's different from ORDER BY
+		if n.SampleBy != nil {
+			if _, isIdent := n.SampleBy.(*ast.Identifier); !isIdent {
+				// Check if SAMPLE BY equals ORDER BY - if so, don't show it
+				showSampleBy := true
+				if len(n.OrderBy) == 1 {
+					var orderBySb, sampleBySb strings.Builder
+					Node(&orderBySb, n.OrderBy[0], 0)
+					Node(&sampleBySb, n.SampleBy, 0)
+					if orderBySb.String() == sampleBySb.String() {
+						showSampleBy = false
+					}
+				}
+				if showSampleBy {
+					storageChildren++
+				}
+			}
+		}
 		if len(n.Settings) > 0 {
 			storageChildren++
 		}
@@ -241,6 +260,25 @@ func explainCreateQuery(sb *strings.Builder, n *ast.CreateQuery, indent string,
 				}
 			}
 		}
+		// SAMPLE BY is only shown in EXPLAIN AST when it's a function (not a simple identifier)
+		// and when it's different from ORDER BY
+		if n.SampleBy != nil {
+			if _, isIdent := n.SampleBy.(*ast.Identifier); !isIdent {
+				// Check if SAMPLE BY equals ORDER BY - if so, don't show it
+				showSampleBy := true
+				if len(n.OrderBy) == 1 {
+					var orderBySb, sampleBySb strings.Builder
+					Node(&orderBySb, n.OrderBy[0], 0)
+					Node(&sampleBySb, n.SampleBy, 0)
+					if orderBySb.String() == sampleBySb.String() {
+						showSampleBy = false
+					}
+				}
+				if showSampleBy {
+					Node(sb, n.SampleBy, depth+2)
+				}
+			}
+		}
 		if len(n.Settings) > 0 {
 			fmt.Fprintf(sb, "%s  Set\n", indent)
 		}

lexer/lexer.go

@@ -425,6 +425,35 @@ func (l *Lexer) readString(quote rune) Item {
 	return Item{Token: token.STRING, Value: sb.String(), Pos: pos}
 }
 
+func (l *Lexer) readHexString() Item {
+	pos := l.pos
+	var sb strings.Builder
+	l.readChar() // skip opening quote
+
+	for !l.eof {
+		if l.ch == '\'' {
+			l.readChar() // skip closing quote
+			break
+		}
+		// Read two hex digits and convert to byte
+		hex1 := l.ch
+		l.readChar()
+		if l.eof || l.ch == '\'' {
+			// Odd number of hex digits - write single value
+			sb.WriteByte(byte(hexValue(hex1)))
+			if l.ch == '\'' {
+				l.readChar() // skip closing quote
+			}
+			break
+		}
+		hex2 := l.ch
+		val := hexValue(hex1)*16 + hexValue(hex2)
+		sb.WriteByte(byte(val))
+		l.readChar()
+	}
+	return Item{Token: token.STRING, Value: sb.String(), Pos: pos}
+}
+
 func (l *Lexer) readQuotedIdentifier() Item {
 	pos := l.pos
 	var sb strings.Builder
@@ -841,7 +870,7 @@ func (l *Lexer) readIdentifier() Item {
 	// Check for hex string literal: x'...' or X'...'
 	if (l.ch == 'x' || l.ch == 'X') && l.peekChar() == '\'' {
 		l.readChar() // skip x
-		return l.readString('\'') // read as regular string
+		return l.readHexString() // read as hex-decoded string
 	}
 
 	// Check for binary string literal: b'...' or B'...'

parser/testdata/00975_sample_prewhere_distributed/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}

parser/testdata/01942_untuple_transformers_msan/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}

parser/testdata/02590_bson_duplicate_column/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}

parser/testdata/02813_system_licenses_base/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}