[PR #267] [MERGED] Fix incorrect connection string format in README.md example #270

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2026-02-16T05:17:10-05:00

yindo commented

2026-02-16 05:17:10 -05:00

📋 Pull Request Information

Original PR: https://github.com/langchain-ai/langchain-postgres/pull/267
Author: @yukiharada1228
Created: 11/5/2025
Status: ✅ Merged
Merged: 11/14/2025
Merged by: @averikitsch

Base: main ← Head: main

📝 Commits (1)

c2c8add Update README.md

📊 Changes

1 file changed (+1 additions, -1 deletions)

View changed files

📝 README.md (+1 -1)

📄 Description

The connection string example in README.md is incorrect.

Currently, README.md shows:

CONNECTION_STRING = "postgresql+psycopg3://langchain:langchain@localhost:6024/langchain"

However, this format causes the following error:

NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:postgresql.psycopg3

The actual example files (examples/vectorstore.ipynb, examples/pg_vectorstore.ipynb, etc.) use the correct format postgresql+psycopg://, which works correctly.

The examples/vectorstore.ipynb also explicitly states: "the driver name is psycopg not psycopg3, but it'll use psycopg3."

Proposed fix:
Line 46 in README.md should be changed from:

CONNECTION_STRING = "postgresql+psycopg3://langchain:langchain@localhost:6024/langchain"

to:

CONNECTION_STRING = "postgresql+psycopg://langchain:langchain@localhost:6024/langchain"

_{🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.}

## 📋 Pull Request Information **Original PR:** https://github.com/langchain-ai/langchain-postgres/pull/267 **Author:** [@yukiharada1228](https://github.com/yukiharada1228) **Created:** 11/5/2025 **Status:** ✅ Merged **Merged:** 11/14/2025 **Merged by:** [@averikitsch](https://github.com/averikitsch) **Base:** `main` ← **Head:** `main` --- ### 📝 Commits (1) - [`c2c8add`](https://github.com/langchain-ai/langchain-postgres/commit/c2c8add875c7a1500971eb7189ed0cfd9992420b) Update README.md ### 📊 Changes **1 file changed** (+1 additions, -1 deletions) <details> <summary>View changed files</summary> 📝 `README.md` (+1 -1) </details> ### 📄 Description The connection string example in README.md is incorrect. Currently, README.md shows: ```python CONNECTION_STRING = "postgresql+psycopg3://langchain:langchain@localhost:6024/langchain" ``` However, this format causes the following error: ``` NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:postgresql.psycopg3 ``` The actual example files (`examples/vectorstore.ipynb`, `examples/pg_vectorstore.ipynb`, etc.) use the correct format `postgresql+psycopg://`, which works correctly. The `examples/vectorstore.ipynb` also explicitly states: "the driver name is `psycopg` not `psycopg3`, but it'll use `psycopg3`." **Proposed fix:** Line 46 in README.md should be changed from: ```python CONNECTION_STRING = "postgresql+psycopg3://langchain:langchain@localhost:6024/langchain" ``` to: ```python CONNECTION_STRING = "postgresql+psycopg://langchain:langchain@localhost:6024/langchain" ``` --- <sub>🔄 This issue represents a GitHub Pull Request. It cannot be merged through Gitea due to API limitations.</sub>

yindo added the pull-request label 2026-02-16 05:17:10 -05:00

yindo closed this issue

2026-02-16 05:17:10 -05:00

yindo referenced this issue

2026-02-16 05:17:11 -05:00

[PR #270] [MERGED] fix: reindex&drop_index without schema #272

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Reference: langchain-ai/langchain-postgres#270