clickhouse

ClickHouse Handler Library

This library provides a utility for interacting with a ClickHouse database. It includes functionality for loading configuration, establishing a connection, executing queries, and managing the database session.

Features

• Load ClickHouse configuration from environment variables.
• Establish a secure connection to the ClickHouse database.
• Execute queries and statements.
• Manage the database session lifecycle.

Configuration

The library expects the following environment variables to be set:

• CLICKHOUSE_HOSTNAME: The hostname of the ClickHouse server.
• CLICKHOUSE_USERNAME: The username for authentication.
• CLICKHOUSE_PASSWORD: The password for authentication.
• CLICKHOUSE_DATABASE: The name of the database to connect to.
• CLICKHOUSE_PORT: The port number of the ClickHouse server.
• CLICKHOUSE_SKIP_VERIFY: Whether to skip TLS verification (true or false).

Usage

Loading Configuration

Use the ClickhouseLoadConfig function to load the configuration from environment variables:

config, err := ClickhouseLoadConfig()
if err != nil {
    log.Fatalf("Failed to load ClickHouse configuration: %v", err.Error())
}

Creating a ClickHouse Session

Use the NewClickhouseSession function to create a new session:

ctx := context.Background()
session, err := NewClickhouseSession(config, ctx)
if err != nil {
    log.Fatalf("Failed to create ClickHouse session: %v", err.Error())
}
defer session.Close()

Executing Queries

Querying Data

Use the Query method to execute a query and retrieve rows:

rows, err := session.Query(ctx, "SELECT * FROM my_table")
if err != nil {
    log.Fatalf("Query failed: %v", err.Error())
}
defer rows.Close()

Executing Statements

Use the Exec method to execute a statement:

err := session.Exec(ctx, "INSERT INTO my_table (id, name) VALUES (1, 'example')")
if err != nil {
    log.Fatalf("Execution failed: %v", err.Error())
}

Closing the Session

Always close the session when done:

err := session.Close()
if err != nil {
    log.Fatalf("Failed to close ClickHouse session: %v", err.Error())
}

Error Handling

Ensure proper error handling when loading configuration, creating a session, or executing queries, as invalid credentials or connection issues will result in errors.

Dependencies

This library uses the following dependencies:

• ClickHouse Go: Go client for ClickHouse.
• spf13/viper: Configuration management for Go.