https://github.com/sun1211/postgresql-docker-replication
This guide explains how to set up a PostgreSQL database with Docker, configure master-slave replication, and use TypeORM for database operations in a Node.js app. It includes PostgreSQL commands, basic queries, and examples of read/write operations using TypeORM. Perfect for quickly deploying PostgreSQL with TypeORM.
https://github.com/sun1211/postgresql-docker-replication
database-replication docker postgresql typeorm
Last synced: 4 months ago
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This guide explains how to set up a PostgreSQL database with Docker, configure master-slave replication, and use TypeORM for database operations in a Node.js app. It includes PostgreSQL commands, basic queries, and examples of read/write operations using TypeORM. Perfect for quickly deploying PostgreSQL with TypeORM.
- Host: GitHub
- URL: https://github.com/sun1211/postgresql-docker-replication
- Owner: sun1211
- Created: 2022-06-25T13:45:17.000Z (about 3 years ago)
- Default Branch: main
- Last Pushed: 2024-08-30T16:41:04.000Z (10 months ago)
- Last Synced: 2025-01-08T06:35:30.908Z (6 months ago)
- Topics: database-replication, docker, postgresql, typeorm
- Language: JavaScript
- Homepage:
- Size: 12.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# PostgreSQL Example
## Single PostgreSQL Instance
### Requirements
- **Docker**: [Install Docker](https://docs.docker.com/compose/install/)
- **Yarn**: Version `v1.22.17` or higher
- **Node.js**: Version `v14.17.0` or higher
- **PostgreSQL**:
- **Windows**: [Install PostgreSQL](https://www.postgresqltutorial.com/postgresql-getting-started/install-postgresql/)
- **Linux**: [Install PostgreSQL](https://www.postgresqltutorial.com/postgresql-getting-started/install-postgresql-linux/)
- **macOS**: [Install PostgreSQL](https://www.postgresqltutorial.com/postgresql-getting-started/install-postgresql-macos/)
### Steps to Start PostgreSQL
1. **Start PostgreSQL using Docker**:
```bash
yarn run start-postgres
```
2. **Run the Example Application**:
```bash
yarn run start
```
3. **Connect to the PostgreSQL Docker Container**:
```bash
docker exec -it bash
psql -U postgres
```
### Basic PostgreSQL Queries
- **SELECT Statement**:
```sql
SELECT
select_list
FROM
table_name;
```
- **Explanation**:
- **select_list**: The columns to retrieve data from; use `*` to select all columns.
- **table_name**: The table from which to query data.
- **Column Alias**:
```sql
SELECT column_name AS alias_name
FROM table_name;
```
Or:
```sql
SELECT column_name alias_name
FROM table_name;
```
Or:
```sql
SELECT expression AS alias_name
FROM table_name;
```
- **ORDER BY Clause**:
```sql
SELECT
select_list
FROM
table_name
ORDER BY
sort_expression1 [ASC | DESC],
sort_expressionN [ASC | DESC];
```
- **DISTINCT Clause**:
```sql
SELECT
DISTINCT column1, column2
FROM
table_name;
```
- Removes duplicate rows from the result set.
## PostgreSQL Replication
### Steps to Set Up Replication
1. **Create and Grant Access to Slave User on Master**:
After starting the Docker container, connect to the master PostgreSQL instance:
```bash
docker exec -it bash
psql -U postgres -d development_database
```
Then, create the table and grant access:
```sql
CREATE TABLE users (
id SERIAL PRIMARY KEY,
first_name VARCHAR(255) NOT NULL,
last_name VARCHAR(255) NOT NULL,
email VARCHAR(255) NOT NULL
);
INSERT INTO users (first_name, last_name, email)
VALUES ('John', 'Doe', '[email protected]');
GRANT SELECT ON users TO repl_user;
```
2. **Read Data from Slave User**:
Access the slave PostgreSQL instance:
```bash
docker exec -it bash
psql -U repl_user -d development_database
```
Execute the following query:
```sql
SELECT * FROM users;
```
### Notes
- **Delete Table if it Exists**:
```sql
DROP TABLE IF EXISTS users;
```
### Example API Endpoints
#### Create a User (Write to Database)
```javascript
// Create user endpoint
app.post('/users', async (req, res) => {
console.log(req.body);
try {
const { firstName, lastName, email } = req.body;
const user = await createUser(firstName, lastName, email);
res.status(201).json(user);
} catch (error) {
console.error('Failed to create user:', error);
res.status(500).json({ message: 'Failed to create user' });
}
});
```
Test the endpoint using `curl`:
```bash
curl -X POST \
'http://localhost:4000/users' \
--header 'Accept: */*' \
--header 'User-Agent: Thunder Client (https://www.thunderclient.com)' \
--header 'Content-Type: application/json' \
--data-raw '{
"firstName": "test",
"lastName" : "demo",
"email": "[email protected]"
}'
```
#### Get All Users (Read from Database)
```javascript
// Get users endpoint
app.get('/users', async (req, res) => {
try {
const users = await getAllUsers();
res.status(200).json(users);
} catch (error) {
console.error('Failed to retrieve users:', error);
res.status(500).json({ message: 'Failed to retrieve users' });
}
});
```
Test the endpoint using `curl`:
```bash
curl -X GET \
'http://localhost:4000/users' \
--header 'Accept: */*' \
--header 'User-Agent: Thunder Client (https://www.thunderclient.com)'
```
### Summary
- Use Docker to start and manage your PostgreSQL instances.
- Set up master-slave replication for PostgreSQL.
- Perform basic read and write operations using Node.js with TypeORM.
- Test the API endpoints using `curl` commands.