Support DROP POLICY statement

Author: nene

src/cst/Policy.ts

@@ -4,7 +4,7 @@ import { Identifier, EntityName, Expr, ParenExpr, ListExpr } from "./Expr";
 
 export type AllPolicyNodes = AllPolicyStatements | CreatePolicyClause;
 
-export type AllPolicyStatements = CreatePolicyStmt;
+export type AllPolicyStatements = CreatePolicyStmt | DropPolicyStmt;
 
 // CREATE POLICY name ON table
 export interface CreatePolicyStmt extends BaseNode {
@@ -60,3 +60,13 @@ export interface PolicyCheckClause extends BaseNode {
   checkKw: Keyword<"CHECK">;
   expr: ParenExpr<Expr>;
 }
+
+export interface DropPolicyStmt extends BaseNode {
+  type: "drop_policy_stmt";
+  dropPolicyKw: [Keyword<"DROP">, Keyword<"POLICY">];
+  ifExistsKw?: [Keyword<"IF">, Keyword<"EXISTS">];
+  name: Identifier;
+  onKw: Keyword<"ON">;
+  table: EntityName;
+  behaviorKw?: Keyword<"CASCADE" | "RESTRICT">;
+}

src/parser.pegjs

@@ -171,6 +171,7 @@ ddl_statement_postgres
   / set_role_stmt
   / reset_role_stmt
   / create_policy_stmt
+  / drop_policy_stmt
 
 dml_statement
   = compound_select_stmt
@@ -4703,6 +4704,19 @@ policy_check_clause
     return loc({ type: "policy_check_clause", withKw: read(withKw), checkKw: read(checkKw), expr });
   }
 
+drop_policy_stmt
+  = kw:(DROP __ POLICY __) ifExistsKw:(if_exists __)? name:(ident __) onKw:(ON __) table:entity_name behaviorKw:(__ (CASCADE / RESTRICT))? {
+    return loc({
+      type: "drop_policy_stmt",
+      dropPolicyKw: read(kw),
+      ifExistsKw: read(ifExistsKw),
+      name: read(name),
+      onKw: read(onKw),
+      table,
+      behaviorKw: read(behaviorKw),
+    });
+  }
+
 /**
  * ------------------------------------------------------------------------------------ *
  *                                                                                      *

src/showNode/policy.ts

@@ -14,4 +14,15 @@ export const policyMap: FullTransformMap<string, AllPolicyNodes> = {
   policy_roles_clause: (node) => show([node.toKw, node.roles]),
   policy_using_clause: (node) => show([node.usingKw, node.expr]),
   policy_check_clause: (node) => show([node.withKw, node.checkKw, node.expr]),
+
+  // DROP POLICY
+  drop_policy_stmt: (node) =>
+    show([
+      node.dropPolicyKw,
+      node.ifExistsKw,
+      node.name,
+      node.onKw,
+      node.table,
+      node.behaviorKw,
+    ]),
 };

test/ddl/policy.test.ts

@@ -47,6 +47,22 @@ describe("policy", () => {
         `);
       });
     });
+
+    describe("DROP POLICY", () => {
+      it("supports CREATE POLICY .. ON ..", () => {
+        testWc("DROP POLICY foo ON my_table");
+        testWc("DROP POLICY foo ON my_schema.my_table");
+      });
+
+      it("supports IF EXISTS", () => {
+        testWc("DROP POLICY IF EXISTS foo ON my_table");
+      });
+
+      it("supports CASCADE/RESTRICT", () => {
+        testWc("DROP POLICY foo ON my_table CASCADE");
+        testWc("DROP POLICY foo ON my_table RESTRICT");
+      });
+    });
   });
 
   notDialect("postgresql", () => {