Add support of the format clause for the select stmt (#79)

Author: laojianzi

parser/ast.go

@@ -4942,6 +4942,7 @@ type SelectQuery struct {
 	LimitBy       *LimitByClause
 	Limit         *LimitClause
 	Settings      *SettingsClause
+	Format        *FormatClause
 	UnionAll      *SelectQuery
 	UnionDistinct *SelectQuery
 	Except        *SelectQuery
@@ -5026,6 +5027,10 @@ func (s *SelectQuery) String(level int) string { // nolint: funlen
 		builder.WriteString(NewLine(level))
 		builder.WriteString(s.Settings.String(level))
 	}
+	if s.Format != nil {
+		builder.WriteString(NewLine(level))
+		builder.WriteString(s.Format.String(level))
+	}
 	if s.UnionAll != nil {
 		builder.WriteString(NewLine(level))
 		builder.WriteString(" UNION ALL ")
@@ -5115,6 +5120,11 @@ func (s *SelectQuery) Accept(visitor ASTVisitor) error {
 			return err
 		}
 	}
+	if s.Format != nil {
+		if err := s.Format.Accept(visitor); err != nil {
+			return err
+		}
+	}
 	if s.UnionAll != nil {
 		if err := s.UnionAll.Accept(visitor); err != nil {
 			return err

parser/parser_query.go

@@ -907,6 +907,14 @@ func (p *Parser) parseSelectStmt(pos Pos) (*SelectQuery, error) { // nolint: fun
 		statementEnd = settings.End()
 	}
 
+	format, err := p.tryParseFormat(p.Pos())
+	if err != nil {
+		return nil, err
+	}
+	if format != nil {
+		statementEnd = format.End()
+	}
+
 	return &SelectQuery{
 		With:          withClause,
 		SelectPos:     pos,
@@ -924,6 +932,7 @@ func (p *Parser) parseSelectStmt(pos Pos) (*SelectQuery, error) { // nolint: fun
 		LimitBy:       limitBy,
 		Limit:         limit,
 		Settings:      settings,
+		Format:        format,
 		WithTotal:     withTotal,
 	}, nil
 }

parser/testdata/ddl/output/bug_001.sql.golden.json

@@ -501,6 +501,7 @@
         "LimitBy": null,
         "Limit": null,
         "Settings": null,
+        "Format": null,
         "UnionAll": null,
         "UnionDistinct": null,
         "Except": null

parser/testdata/ddl/output/create_live_view_basic.sql.golden.json

@@ -127,6 +127,7 @@
         "LimitBy": null,
         "Limit": null,
         "Settings": null,
+        "Format": null,
         "UnionAll": null,
         "UnionDistinct": null,
         "Except": null

parser/testdata/ddl/output/create_materialized_view_basic.sql.golden.json

@@ -486,6 +486,7 @@
         "LimitBy": null,
         "Limit": null,
         "Settings": null,
+        "Format": null,
         "UnionAll": null,
         "UnionDistinct": null,
         "Except": null

parser/testdata/ddl/output/create_materialized_view_with_empty_table_schema.sql.golden.json

@@ -427,6 +427,7 @@
                   "LimitBy": null,
                   "Limit": null,
                   "Settings": null,
+                  "Format": null,
                   "UnionAll": null,
                   "UnionDistinct": null,
                   "Except": null
@@ -476,6 +477,7 @@
         "LimitBy": null,
         "Limit": null,
         "Settings": null,
+        "Format": null,
         "UnionAll": null,
         "UnionDistinct": null,
         "Except": null

parser/testdata/ddl/output/create_view_basic.sql.golden.json

@@ -138,6 +138,7 @@
         "LimitBy": null,
         "Limit": null,
         "Settings": null,
+        "Format": null,
         "UnionAll": null,
         "UnionDistinct": null,
         "Except": null

parser/testdata/ddl/output/create_view_on_cluster_with_uuid.sql.golden.json

@@ -93,6 +93,7 @@
         "LimitBy": null,
         "Limit": null,
         "Settings": null,
+        "Format": null,
         "UnionAll": null,
         "UnionDistinct": null,
         "Except": null

parser/testdata/dml/output/insert_with_select.sql.golden.json

@@ -93,6 +93,7 @@
       "LimitBy": null,
       "Limit": null,
       "Settings": null,
+      "Format": null,
       "UnionAll": null,
       "UnionDistinct": null,
       "Except": null

parser/testdata/query/format/select_with_union_distinct.sql

@@ -11,4 +11,5 @@ FROM
 SELECT 
   replica_name
 FROM
-  system.ha_unique_replicas;
+  system.ha_unique_replicas
+FORMAT JSON;