feat: support comment on in pg

Author: taozhi8833998

pegjs/postgresql.pegjs

@@ -239,6 +239,7 @@ cmd_stmt
   / execute_stmt
   / for_loop_stmt
   / transaction_stmt
+  / comment_on_stmt
 
 create_stmt
   = create_table_stmt
@@ -3052,6 +3053,46 @@ transaction_stmt
       }
     }
   }
+comment_on_option
+  = t:(KW_TABLE / KW_VIEW) __ name:table_name {
+    // => { type: string; name: table_name; }
+    return {
+      type: t.toLowerCase(),
+      name: name,
+    }
+  }
+  / t:(KW_COLUMN) __ name:column_ref {
+    // => { type: string; name: column_ref; }
+    return {
+      type: t.toLowerCase(),
+      name: name,
+    }
+  }
+
+comment_on_is
+  = 'IS'i __ e:(literal_string / literal_null) {
+    // => { keyword: 'is'; expr: literal_string | literal_null; }
+    return {
+      keyword: 'is',
+      expr: e,
+    }
+  }
+comment_on_stmt
+  = 'COMMENT'i __ 'ON'i __ co:comment_on_option __ is:comment_on_is {
+    /* export interface comment_on_stmt_t {
+        type: 'comment';
+        target: comment_on_option;
+        expr: comment_on_is;
+      }
+      => AstStatement<comment_on_stmt_t>
+     */
+    return {
+      type: 'comment',
+      keyword: 'on',
+      target: co,
+      expr: is,
+    }
+  }
 select_stmt
   = KW_SELECT __ ';' {
     // => { type: 'select'; }

src/comment.js

@@ -0,0 +1,34 @@
+import { columnRefToSQL } from './column'
+import { hasVal, identifierToSql, literalToSQL, toUpper } from './util'
+
+function commentOptionToSQL(stmt) {
+  const { name, type } = stmt
+  switch (type) {
+    case 'table':
+    case 'view':
+      const fullTableName = [identifierToSql(name.db), identifierToSql(name.table)].filter(hasVal).join('.')
+      return `${toUpper(type)} ${fullTableName}`
+    case 'column':
+      return `COLUMN ${columnRefToSQL(name)}`
+  }
+}
+
+function commentIsExprToSQL(stmt) {
+  const { keyword, expr } = stmt
+  return [toUpper(keyword), literalToSQL(expr)].filter(hasVal).join(' ')
+}
+
+function commentOnToSQL(stmt) {
+  const { expr, keyword, target, type } = stmt
+  const result = [
+    toUpper(type),
+    toUpper(keyword),
+    commentOptionToSQL(target),
+    commentIsExprToSQL(expr),
+  ]
+  return result.filter(hasVal).join(' ')
+}
+
+export {
+  commentOnToSQL,
+}

src/sql.js

@@ -1,6 +1,6 @@
 import { unionToSQL, multipleToSQL } from './union'
 
-const supportedTypes = ['analyze', 'attach', 'select', 'deallocate', 'delete', 'exec', 'update', 'insert', 'drop', 'rename', 'truncate', 'call', 'desc', 'use', 'alter', 'set', 'create', 'lock', 'unlock', 'declare', 'show', 'replace', 'if', 'grant', 'revoke', 'proc', 'raise', 'execute', 'transaction', 'explain']
+const supportedTypes = ['analyze', 'attach', 'select', 'deallocate', 'delete', 'exec', 'update', 'insert', 'drop', 'rename', 'truncate', 'call', 'desc', 'use', 'alter', 'set', 'create', 'lock', 'unlock', 'declare', 'show', 'replace', 'if', 'grant', 'revoke', 'proc', 'raise', 'execute', 'transaction', 'explain', 'comment']
 
 function checkSupported(expr) {
   const ast = expr && expr.ast ? expr.ast : expr

src/union.js

@@ -1,6 +1,7 @@
 import { alterToSQL } from './alter'
 import { analyzeToSQL, attachToSQL } from './analyze'
 import { createToSQL } from './create'
+import { commentOnToSQL } from './comment'
 import { explainToSQL } from './explain'
 import { selectToSQL } from './select'
 import { deleteToSQL } from './delete'
@@ -35,6 +36,7 @@ const typeToSQLFn = {
   analyze     : analyzeToSQL,
   attach      : attachToSQL,
   create      : createToSQL,
+  comment     : commentOnToSQL,
   select      : selectToSQL,
   deallocate  : deallocateToSQL,
   delete      : deleteToSQL,

test/postgres.spec.js

@@ -1943,6 +1943,20 @@ describe('Postgres', () => {
           'SELECT "meeting".end FROM "meeting"'
         ]
       },
+      {
+        title: 'comment on table',
+        sql: [
+          "COMMENT ON TABLE users IS 'users table';",
+          `COMMENT ON TABLE "users" IS 'users table'`
+        ]
+      },
+      {
+        title: 'comment on column',
+        sql: [
+          `COMMENT ON COLUMN "users"."name" IS 'first name and last name';`,
+          `COMMENT ON COLUMN "users"."name" IS 'first name and last name'`
+        ]
+      },
     ]
     neatlyNestTestedSQL(SQL_LIST)
   })