Clone full ColumnRef (#1254)

In a few places we just clone the name. It became a problem, as
`top_hits' CTE` lost information somewhere about its table name and
produced SQL without it.

Author: trzysiek

quesma/model/base_visitor.go

@@ -79,7 +79,7 @@ func (v *BaseExprVisitor) VisitColumnRef(e ColumnRef) interface{} {
 	if v.OverrideVisitColumnRef != nil {
 		return v.OverrideVisitColumnRef(v, e)
 	}
-	return NewColumnRef(e.ColumnName)
+	return e.Clone()
 }
 
 func (v *BaseExprVisitor) VisitNestedProperty(e NestedProperty) interface{} {

quesma/model/expr.go

@@ -29,10 +29,18 @@ func NewColumnRef(name string) ColumnRef {
 	return ColumnRef{ColumnName: name}
 }
 
+func NewColumnRefWithTable(name, tableAlias string) ColumnRef {
+	return ColumnRef{ColumnName: name, TableAlias: tableAlias}
+}
+
 func (e ColumnRef) Accept(v ExprVisitor) interface{} {
 	return v.VisitColumnRef(e)
 }
 
+func (e ColumnRef) Clone() ColumnRef {
+	return ColumnRef{TableAlias: e.TableAlias, ColumnName: e.ColumnName}
+}
+
 // PrefixExpr represents unary operators, e.g. NOT, - etc.
 type PrefixExpr struct {
 	Op   string

quesma/optimize/split_time_range.go

@@ -243,7 +243,7 @@ func (s splitTimeRange) transformQuery(query *model.Query, properties map[string
 	for i, column := range namedCTEs[0].SelectCommand.Columns {
 		switch column := (column).(type) {
 		case model.ColumnRef:
-			selectedColumns[i] = model.NewColumnRef(column.ColumnName)
+			selectedColumns[i] = column.Clone()
 		case model.LiteralExpr:
 			selectedColumns[i] = model.NewColumnRef(column.Value.(string))
 		case model.AliasedExpr:

quesma/quesma/schema_transformer.go

@@ -411,7 +411,7 @@ func (s *SchemaCheckPass) applyPhysicalFromExpression(currentSchema schema.Schem
 		// TODO is this nessessery?
 		if useCommonTable {
 			if e.ColumnName == "timestamp" || e.ColumnName == "epoch_time" || e.ColumnName == `"epoch_time"` {
-				return model.NewColumnRef("@timestamp")
+				return model.NewColumnRefWithTable("@timestamp", e.TableAlias)
 			}
 		}
 		return e
@@ -602,7 +602,8 @@ func (s *SchemaCheckPass) applyFullTextField(indexSchema schema.Schema, query *m
 				var expressions []model.Expr
 
 				for _, field := range fullTextFields {
-					expressions = append(expressions, model.NewInfixExpr(model.NewColumnRef(field), e.Op, e.Right))
+					colRef := model.NewColumnRefWithTable(field, col.TableAlias)
+					expressions = append(expressions, model.NewInfixExpr(colRef, e.Op, e.Right))
 				}
 
 				res := model.Or(expressions)
@@ -644,7 +645,7 @@ func (s *SchemaCheckPass) applyTimestampField(indexSchema schema.Schema, query *
 			timestampColumnName = *table.DiscoveredTimestampFieldName
 		}
 	*/
-	var replacementExpr model.Expr
+	var replacementName string
 
 	if timestampColumnName == "" {
 		// no timestamp field found, replace with NULL if any
@@ -662,12 +663,12 @@ func (s *SchemaCheckPass) applyTimestampField(indexSchema schema.Schema, query *
 
 		// if the target column is not the canonical timestamp field, replace it
 		if timestampColumnName != model.TimestampFieldName {
-			replacementExpr = model.NewColumnRef(timestampColumnName)
+			replacementName = timestampColumnName
 		}
 	}
 
 	// no replacement needed
-	if replacementExpr == nil {
+	if replacementName == "" {
 		return query, nil
 	}
 
@@ -676,7 +677,7 @@ func (s *SchemaCheckPass) applyTimestampField(indexSchema schema.Schema, query *
 
 		// full text field should be used only in where clause
 		if e.ColumnName == model.TimestampFieldName {
-			return replacementExpr
+			return model.NewColumnRefWithTable(replacementName, e.TableAlias)
 		}
 		return e
 	}
@@ -713,7 +714,7 @@ func (s *SchemaCheckPass) applyFieldEncoding(indexSchema schema.Schema, query *m
 		}
 
 		if resolvedField, ok := indexSchema.ResolveField(e.ColumnName); ok {
-			return model.NewColumnRef(resolvedField.InternalPropertyName.AsString())
+			return model.NewColumnRefWithTable(resolvedField.InternalPropertyName.AsString(), e.TableAlias)
 		} else {
 			if hasAttributesValuesColumn {
 				return model.NewArrayAccess(model.NewColumnRef(clickhouse.AttributesValuesColumn), model.NewLiteral(fmt.Sprintf("'%s'", e.ColumnName)))

quesma/testdata/requests_with_special_characters.go

@@ -158,8 +158,8 @@ var AggregationTestsWithSpecialCharactersInFieldNames = []AggregationTestCase{
 				"metric____quesma_total_count_col_0",
 				"group_table"."aggr__0__key_0" AS "aggr__0__key_0",
 				"group_table"."aggr__0__count" AS "aggr__0__count",
-				"__bytes" AS "top_metrics__0__1_col_0",
-				"__timestamp" AS "top_metrics__0__1_col_1",
+				"hit_table"."__bytes" AS "top_metrics__0__1_col_0",
+				"hit_table"."__timestamp" AS "top_metrics__0__1_col_1",
 				ROW_NUMBER() OVER (PARTITION BY "group_table"."aggr__0__key_0" ORDER BY
 				"__timestamp" DESC) AS "top_hits_rank"
 			  FROM quesma_top_hits_group_table AS "group_table" LEFT OUTER JOIN