From 2494ed703debc1e74f2eb370ad5613607bf87467 Mon Sep 17 00:00:00 2001
From: George Herbert <github@georgeherby.dev>
Date: Sun, 26 May 2024 03:33:03 +0100
Subject: [PATCH] community[patch]: add ?| (arrayContains) filter on metadata
 to PGVector search (#5381)

* add ?| (arrayContains) filter on metadata to PGVector search

* fix: align to style of IN filter

* Format

* Update build artifacts

* Format

---------

Co-authored-by: jacoblee93 <jacoblee93@gmail.com>
---
 .../pgvector_vectorstore/pgvector.ts          | 17 ++++++++-
 .../src/vectorstores/pgvector.ts              | 12 ++++++
 .../tests/pgvector/pgvector.int.test.ts       | 38 +++++++++++++++++++
 3 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/examples/src/indexes/vector_stores/pgvector_vectorstore/pgvector.ts b/examples/src/indexes/vector_stores/pgvector_vectorstore/pgvector.ts
index 849dd657b4c9..3a006298d9ba 100644
--- a/examples/src/indexes/vector_stores/pgvector_vectorstore/pgvector.ts
+++ b/examples/src/indexes/vector_stores/pgvector_vectorstore/pgvector.ts
@@ -34,8 +34,8 @@ const pgvectorStore = await PGVectorStore.initialize(
 );
 
 await pgvectorStore.addDocuments([
-  { pageContent: "what's this", metadata: { a: 2 } },
-  { pageContent: "Cat drinks milk", metadata: { a: 1 } },
+  { pageContent: "what's this", metadata: { a: 2, b: ["tag1", "tag2"] } },
+  { pageContent: "Cat drinks milk", metadata: { a: 1, b: ["tag2"] } },
 ]);
 
 const results = await pgvectorStore.similaritySearch("water", 1);
@@ -84,4 +84,17 @@ console.log(results4);
   [ Document { pageContent: 'what's this', metadata: { a: 2 } } ]
 */
 
+// Filtering using arrayContains (?|) is supported
+const results5 = await pgvectorStore.similaritySearch("water", 1, {
+  b: {
+    arrayContains: ["tag1"],
+  },
+});
+
+console.log(results5);
+
+/*
+  [ Document { pageContent: "what's this", metadata: { a: 2, b: ['tag1', 'tag2'] } } } ]
+*/
+
 await pgvectorStore.end();
diff --git a/libs/langchain-community/src/vectorstores/pgvector.ts b/libs/langchain-community/src/vectorstores/pgvector.ts
index 9961ebe76bd0..af5ac76bc047 100644
--- a/libs/langchain-community/src/vectorstores/pgvector.ts
+++ b/libs/langchain-community/src/vectorstores/pgvector.ts
@@ -501,6 +501,18 @@ export class PGVectorStore extends VectorStore {
           parameters.push(..._value.in);
           paramCount += _value.in.length;
         }
+        if (Array.isArray(_value.arrayContains)) {
+          const placeholders = _value.arrayContains
+            .map(
+              (_: unknown, index: number) => `$${currentParamCount + index + 1}`
+            )
+            .join(",");
+          whereClauses.push(
+            `${this.metadataColumnName}->'${key}' ?| array[${placeholders}]`
+          );
+          parameters.push(..._value.arrayContains);
+          paramCount += _value.arrayContains.length;
+        }
       } else {
         paramCount += 1;
         whereClauses.push(
diff --git a/libs/langchain-community/src/vectorstores/tests/pgvector/pgvector.int.test.ts b/libs/langchain-community/src/vectorstores/tests/pgvector/pgvector.int.test.ts
index 54fc42d5de05..c22627443912 100644
--- a/libs/langchain-community/src/vectorstores/tests/pgvector/pgvector.int.test.ts
+++ b/libs/langchain-community/src/vectorstores/tests/pgvector/pgvector.int.test.ts
@@ -141,6 +141,44 @@ describe("PGVectorStore", () => {
     expect(result3.length).toEqual(3);
   });
 
+  test("PGvector supports arrayContains (?|) in metadata filter ", async () => {
+    const documents = [
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag1", "tag2"] } },
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag2"] } },
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag1"] } },
+    ];
+
+    await pgvectorVectorStore.addDocuments(documents);
+
+    const result = await pgvectorVectorStore.similaritySearch("hello", 2, {
+      a: {
+        arrayContains: ["tag1"],
+      },
+    });
+
+    expect(result.length).toEqual(2);
+    expect(result).toEqual([
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag1", "tag2"] } },
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag1"] } },
+    ]);
+
+    const result2 = await pgvectorVectorStore.similaritySearch("hello", 2, {
+      a: {
+        arrayContains: ["tag2"],
+      },
+    });
+    expect(result2.length).toEqual(2);
+    expect(result2).toEqual([
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag1", "tag2"] } },
+      { pageContent: "Lorem Ipsum", metadata: { a: ["tag2"] } },
+    ]);
+
+    const result3 = await pgvectorVectorStore.similaritySearch("hello", 3);
+
+    expect(result3.length).toEqual(3);
+    expect(result3).toEqual(documents);
+  });
+
   test("PGvector can delete document by id", async () => {
     try {
       const documents = [