Fix #187. Add clear_bindings().

src/sqlite-api.js

@@ -236,6 +236,16 @@ export function Factory(Module) {
     };
   })();
 
+  sqlite3.clear_bindings = (function() {
+    const fname = 'sqlite3_clear_bindings';
+    const f = Module.cwrap(fname, ...decl('n:n'));
+    return function(stmt) {
+      verifyStatement(stmt);
+      const result = f(stmt);
+      return check(fname, result, mapStmtToDB.get(stmt));
+    };
+  })();
+
   sqlite3.close = (function() {
     const fname = 'sqlite3_close';
     const f = Module.cwrap(fname, ...decl('n:n'), { async });

src/types/index.d.ts

@@ -330,6 +330,14 @@ declare interface SQLiteAPI {
    */
   changes(db): number;
 
+  /**
+   * Reset all bindings on a prepared statement.
+   * @see https://www.sqlite.org/c3ref/clear_bindings.html
+   * @param stmt prepared statement pointer
+   * @returns `SQLITE_OK` (throws exception on error)
+   */
+  clear_bindings(stmt: number): number;
+
   /**
    * Close database connection
    * @see https://www.sqlite.org/c3ref/close.html

test/api_statements.js

@@ -366,6 +366,41 @@ export function api_statements(context) {
       rc = await sqlite3.finalize(stmt);
       expect(rc).toEqual(SQLite.SQLITE_OK);
     });
+
+    it('should clear bindings', async function() {
+      let rc;
+
+      const sql = 'SELECT ?';
+      for await (const stmt of i(sqlite3.statements(db, sql))) {
+        {
+          rc = await sqlite3.bind_int(stmt, 1, 42);
+          expect(rc).toEqual(SQLite.SQLITE_OK);
+
+          rc = await sqlite3.reset(stmt);
+          expect(rc).toEqual(SQLite.SQLITE_OK);
+
+          rc = await sqlite3.step(stmt);
+          expect(rc).toEqual(SQLite.SQLITE_ROW);
+
+          const value = await sqlite3.column(stmt, 0);
+          expect(value).toEqual(42);
+        }
+
+        {
+          rc = await sqlite3.clear_bindings(stmt);
+          expect(rc).toEqual(SQLite.SQLITE_OK);
+
+          rc = await sqlite3.reset(stmt);
+          expect(rc).toEqual(SQLite.SQLITE_OK);
+
+          rc = await sqlite3.step(stmt);
+          expect(rc).toEqual(SQLite.SQLITE_ROW);        
+
+          const value = await sqlite3.column(stmt, 0);
+          expect(value).not.toEqual(42);
+        }
+      }
+    });
   });
 }