Adding support to table comment

Signed-off-by: Sharad Gaur <sharadgaur@gmail.com>

parser/ast.go

@@ -1490,6 +1490,7 @@ type CreateTable struct {
 	Engine       *EngineExpr
 	SubQuery     *SubQuery
 	HasTemporary bool
+	Comment      *StringLiteral
 }
 
 func (c *CreateTable) Pos() Pos {
@@ -1534,6 +1535,10 @@ func (c *CreateTable) String() string {
 		builder.WriteString(" AS ")
 		builder.WriteString(c.SubQuery.String())
 	}
+	if c.Comment != nil {
+		builder.WriteString(" COMMENT ")
+		builder.WriteString(c.Comment.String())
+	}
 	return builder.String()
 }
 

parser/parser_common.go

@@ -137,6 +137,13 @@ func (p *Parser) tryParseUUID() (*UUID, error) {
 	return p.parseUUID()
 }
 
+func (p *Parser) tryParseComment() (*StringLiteral, error) {
+	if p.tryConsumeKeyword(KeywordComment) == nil {
+		return nil, nil
+	}
+	return p.parseString(p.Pos())
+}
+
 func (p *Parser) tryParseIfExists() (bool, error) {
 	if p.tryConsumeKeyword(KeywordIf) == nil {
 		return false, nil

parser/parser_table.go

@@ -166,6 +166,12 @@ func (p *Parser) parseCreateTable(pos Pos) (*CreateTable, error) {
 		createTable.SubQuery = subQuery
 		createTable.StatementEnd = subQuery.End()
 	}
+
+	comment, err := p.tryParseComment()
+	if err != nil {
+		return nil, err
+	}
+	createTable.Comment = comment
 	return createTable, nil
 }
 

parser/testdata/ddl/create_table_basic.sql

@@ -26,4 +26,5 @@ CREATE TABLE IF NOT EXISTS test.events_local (
 PRIMARY KEY (f0, f1, f2)
 PARTITION BY toYYYYMMDD(f3)
 TTL f3 + INTERVAL 6 MONTH
-ORDER BY (f1,f2,f3)
+ORDER BY (f1,f2,f3)
+COMMENT 'Comment for table';

parser/testdata/ddl/format/create_table_basic.sql

@@ -28,6 +28,7 @@ PRIMARY KEY (f0, f1, f2)
 PARTITION BY toYYYYMMDD(f3)
 TTL f3 + INTERVAL 6 MONTH
 ORDER BY (f1,f2,f3)
+COMMENT 'Comment for table';
 
 -- Format SQL:
-CREATE TABLE IF NOT EXISTS test.events_local (f0 String, f1 String CODEC(ZSTD(1)), f2 VARCHAR(255), f3 Datetime, f4 Datetime, f5 Map(String, String), f6 String, f7 Nested(f70 UInt32, f71 UInt32, f72 DateTime, f73 Int64, f74 Int64, f75 String), f8 Datetime DEFAULT now(), f9 String MATERIALIZED toString(f7['f70']), f10 String ALIAS f11) ENGINE = MergeTree PRIMARY KEY (f0, f1, f2) PARTITION BY toYYYYMMDD(f3) TTL f3 + INTERVAL 6 MONTH ORDER BY (f1, f2, f3);
+CREATE TABLE IF NOT EXISTS test.events_local (f0 String, f1 String CODEC(ZSTD(1)), f2 VARCHAR(255), f3 Datetime, f4 Datetime, f5 Map(String, String), f6 String, f7 Nested(f70 UInt32, f71 UInt32, f72 DateTime, f73 Int64, f74 Int64, f75 String), f8 Datetime DEFAULT now(), f9 String MATERIALIZED toString(f7['f70']), f10 String ALIAS f11) ENGINE = MergeTree PRIMARY KEY (f0, f1, f2) PARTITION BY toYYYYMMDD(f3) TTL f3 + INTERVAL 6 MONTH ORDER BY (f1, f2, f3) COMMENT 'Comment for table';

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

@@ -476,6 +476,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -139,6 +139,7 @@
       "OrderBy": null
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -838,6 +838,11 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": {
+      "LiteralPos": 687,
+      "LiteralEnd": 704,
+      "Literal": "Comment for table"
+    }
   }
 ]

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

@@ -763,6 +763,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -817,6 +817,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -244,6 +244,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -422,6 +422,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -476,6 +476,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -304,6 +304,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]

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

@@ -482,6 +482,7 @@
       }
     },
     "SubQuery": null,
-    "HasTemporary": false
+    "HasTemporary": false,
+    "Comment": null
   }
 ]