fix: ALTER TABLE DROP COLUMN only modifies schema, demo page deep-copies query results to prevent reference sharing

dist/metona-sqlark.cjs.js

@@ -5667,15 +5667,8 @@ class QueryExecutor {
             if (!schema.columns[stmt.column.name]) {
                 throw new DatabaseError(`Column "${stmt.column.name}" does not exist in table "${stmt.name}"`, 'COLUMN_NOT_FOUND');
             }
-            // 从 schema 引用上删除列定义（保留所有行数据）
+            // 只从 schema 引用上删除列定义，不碰行数据（避免引用共享导致查询结果被篡改）
             delete schema.columns[stmt.column.name];
-            // 清除已有行中该列的值（MemoryEngine 的 find 返回引用，delete 直接生效）
-            const rows = await this.engine.find(stmt.name, { table: stmt.name });
-            const colName = stmt.column.name;
-            for (const row of rows) {
-                if (colName in row)
-                    delete row[colName];
-            }
         }
     }
     async executeTruncateTable(stmt) {

dist/metona-sqlark.esm.js

@@ -5663,15 +5663,8 @@ class QueryExecutor {
             if (!schema.columns[stmt.column.name]) {
                 throw new DatabaseError(`Column "${stmt.column.name}" does not exist in table "${stmt.name}"`, 'COLUMN_NOT_FOUND');
             }
-            // 从 schema 引用上删除列定义（保留所有行数据）
+            // 只从 schema 引用上删除列定义，不碰行数据（避免引用共享导致查询结果被篡改）
             delete schema.columns[stmt.column.name];
-            // 清除已有行中该列的值（MemoryEngine 的 find 返回引用，delete 直接生效）
-            const rows = await this.engine.find(stmt.name, { table: stmt.name });
-            const colName = stmt.column.name;
-            for (const row of rows) {
-                if (colName in row)
-                    delete row[colName];
-            }
         }
     }
     async executeTruncateTable(stmt) {

dist/metona-sqlark.js

@@ -5669,15 +5669,8 @@
                 if (!schema.columns[stmt.column.name]) {
                     throw new DatabaseError(`Column "${stmt.column.name}" does not exist in table "${stmt.name}"`, 'COLUMN_NOT_FOUND');
                 }
-                // 从 schema 引用上删除列定义（保留所有行数据）
+                // 只从 schema 引用上删除列定义，不碰行数据（避免引用共享导致查询结果被篡改）
                 delete schema.columns[stmt.column.name];
-                // 清除已有行中该列的值（MemoryEngine 的 find 返回引用，delete 直接生效）
-                const rows = await this.engine.find(stmt.name, { table: stmt.name });
-                const colName = stmt.column.name;
-                for (const row of rows) {
-                    if (colName in row)
-                        delete row[colName];
-                }
             }
         }
         async executeTruncateTable(stmt) {

site/demo.html

@@ -221,7 +221,9 @@ async function runQuery() {
     const allResults = [];
     for (const stmt of statements) {
       const result = await db.query(stmt);
-      allResults.push({ sql: stmt, result });
+      // 深拷贝结果，避免引用共享导致后续操作（如 ALTER TABLE DROP COLUMN）修改已渲染的结果
+      const resultCopy = Array.isArray(result) ? result.map(r => ({ ...r })) : result;
+      allResults.push({ sql: stmt, result: resultCopy });
     }
 
     if (allResults.length === 1) {

src/query/executor.ts

@@ -306,14 +306,8 @@ export class QueryExecutor {
       if (!schema.columns[stmt.column.name]) {
         throw new DatabaseError(`Column "${stmt.column.name}" does not exist in table "${stmt.name}"`, 'COLUMN_NOT_FOUND');
       }
-      // 从 schema 引用上删除列定义（保留所有行数据）
+      // 只从 schema 引用上删除列定义，不碰行数据（避免引用共享导致查询结果被篡改）
       delete schema.columns[stmt.column.name];
-      // 清除已有行中该列的值（MemoryEngine 的 find 返回引用，delete 直接生效）
-      const rows = await this.engine.find(stmt.name, { table: stmt.name });
-      const colName = stmt.column.name;
-      for (const row of rows) {
-        if (colName in row) delete row[colName];
-      }
     }
   }
 

test-alter.cjs

@@ -0,0 +1,37 @@
+const { MetonaSqlark } = require('./dist/metona-sqlark.cjs.js');
+
+(async () => {
+  const db = new MetonaSqlark({ name: 'test', mode: 'memory' });
+  await db.init();
+
+  await db.defineTable('users', {
+    id: { type: 'string', primaryKey: true },
+    name: { type: 'string', required: true },
+    email: { type: 'string' },
+    age: { type: 'number', default: 0 },
+  });
+
+  // Step 1: ALTER TABLE ADD COLUMN
+  await db.query('ALTER TABLE users ADD COLUMN phone STRING');
+
+  const schema = await db.getEngine().getTableSchema('users');
+  console.log('Schema columns:', Object.keys(schema.columns));
+
+  // Step 2: INSERT
+  await db.query("INSERT INTO users (id, name, age, phone) VALUES ('6', 'Frank', 33, '123-4567')");
+
+  // Step 3: SELECT (first)
+  const result1 = await db.query("SELECT * FROM users WHERE id = '6'");
+  console.log('First query result:', JSON.stringify(result1));
+  console.log('First query fields:', Object.keys(result1[0]));
+
+  // Step 4: ALTER TABLE DROP COLUMN
+  await db.query('ALTER TABLE users DROP COLUMN phone');
+
+  // Step 5: SELECT (second)
+  const result2 = await db.query("SELECT * FROM users WHERE id = '6'");
+  console.log('Second query result:', JSON.stringify(result2));
+  console.log('Second query fields:', Object.keys(result2[0]));
+
+  await db.close();
+})();