diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..cc1ea8b
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,36 @@
+name: ci
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - 'master'
+    tags:
+      - 'v*'
+  pull_request:
+    branches:
+      - 'master'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v3
+      -
+        name: Login to DockerHub
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      -
+        name: Build and push
+        if: ${{ github.event_name != 'pull_request' }}
+        run: |
+          docker buildx build --platform=linux/amd64 -t ${{ secrets.DOCKERHUB_USERNAME }}/aquery:${{github.sha}} .
+          docker push ${{ secrets.DOCKERHUB_USERNAME }}/aquery:${{github.sha}}
+          docker tag ${{ secrets.DOCKERHUB_USERNAME }}/aquery:${{github.sha}} ${{ secrets.DOCKERHUB_USERNAME }}/aquery:latest
+          docker push ${{ secrets.DOCKERHUB_USERNAME }}/aquery:latest          
diff --git a/README.md b/README.md
index 36d2182..2e6f0f2 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 
 AQuery++ Database is a cross-platform, In-Memory Column-Store Database that incorporates compiled query execution. (**Note**: If you encounter any problems, feel free to contact me via ys3540@nyu.edu)
 
-`## Docker (Recommended): 
+## Docker (Recommended): 
    - See installation instructions from [docker.com](https://www.docker.com). Run **docker desktop** to start docker engine.
    - In AQuery root directory, type `make docker` to build the docker image from scratch. 
    - For Arm-based Mac users, you would have to build and run the **x86_64** docker image because MonetDB doesn't offer official binaries for arm64 Linux. (Run `docker buildx build --platform=linux/amd64 -t aquery .` instead of `make docker`)
diff --git a/reconstruct/ast.py b/reconstruct/ast.py
index 0fa978d..14ab94e 100644
--- a/reconstruct/ast.py
+++ b/reconstruct/ast.py
@@ -296,7 +296,7 @@ class projection(ast_node):
         if 'outfile' in node:
             self.outfile = outfile(self, node['outfile'], sql = self.sql)
             if not self.has_postproc:
-                self.sql += self.outfile.sql
+                self.sql = self.outfile.sql
         else:
             self.outfile = None
         
@@ -398,10 +398,10 @@ class projection(ast_node):
             else:
                 self.context.emitc(f'{self.out_table.contextname_cpp}->printall(" ","\\n", nullptr, nullptr, {self.limit});')
         
-        if self.outfile:
-            self.outfile.finalize()
+        if self.outfile and self.has_postproc:
+                self.outfile.finalize()
 
-        if 'into' in node:
+        if 'into' in node: 
             self.context.emitc(select_into(self, node['into']).ccode)
             self.has_postproc = True
         if not self.distinct:
@@ -417,7 +417,7 @@ class projection(ast_node):
                 self.context.postproc_end(self.postproc_fname)
             else:
                 self.context.ccode = ''
-                if self.limit != 0:
+                if self.limit != 0 and not self.outfile:
                     self.context.direct_output()
         
 class select_distinct(projection):
@@ -1186,8 +1186,8 @@ class outfile(ast_node):
     name="_outfile"
     def __init__(self, parent, node, context = None, *, sql = None):
         self.node = node
-        super().__init__(parent, node, context)
         self.sql = sql if sql else ''
+        super().__init__(parent, node, context)
         
     def init(self, _):
         assert(isinstance(self.parent, projection))
@@ -1207,10 +1207,10 @@ class outfile(ast_node):
     def produce_monetdb(self, node):
         filename = node['loc']['literal'] if 'loc' in node else node['literal']
         import os
-        p = os.path.abspath('.').replace('\\', '/') + '/' + filename
-        self.sql = f'COPY {self.sql} INTO "{p}"'
-        d = '\t'
-        e = '\n'
+        p =  os.path.abspath('.').replace('\\', '/') + '/' + filename
+        self.sql = f'COPY {self.parent.sql} INTO \'{p}\''
+        d = ','
+        e = '\\n'
         if 'term' in node:
             d = node['term']['literal']
         self.sql += f' delimiters \'{d}\', \'{e}\''
diff --git a/reconstruct/storage.py b/reconstruct/storage.py
index 983f866..c8f5e69 100644
--- a/reconstruct/storage.py
+++ b/reconstruct/storage.py
@@ -253,6 +253,10 @@ class Context:
     def direct_output(self):
         self.queries.append('O')
     
+    def abandon_postproc(self):
+        self.ccode = ''
+        self.finalize_query()
+    
     def finalize_udf(self):
         if self.udf is not None:
             return (Context.udf_head