Struct Session 

pub struct Session { /* private fields */ }

A session representing a persistent connection to a chDB database.

A Session manages a connection to a persistent database stored on disk. Unlike stateless queries, sessions allow you to create tables, insert data, and maintain state across multiple queries.

Thread Safety

Session contains a Connection which implements Send, so sessions can be safely transferred between threads. However, concurrent access to the same session should be synchronized.

Examples

use chdb_rust::session::SessionBuilder;
use chdb_rust::arg::Arg;
use chdb_rust::format::OutputFormat;

let session = SessionBuilder::new()
    .with_data_path("/tmp/mydb")
    .with_auto_cleanup(true)
    .build()?;

// Create a table
session.execute(
    "CREATE TABLE users (id UInt64, name String) ENGINE = MergeTree() ORDER BY id",
    None
)?;

// Insert data
session.execute("INSERT INTO users VALUES (1, 'Alice')", None)?;

// Query data
let result = session.execute(
    "SELECT * FROM users",
    Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)])
)?;
println!("{}", result.data_utf8_lossy());

Implementations

impl Session

pub fn execute( &self, query: &str, query_args: Option<&[Arg<'_>]>, ) -> Result<QueryResult, Error>

Execute a query on this session.

This executes a SQL query against the database associated with this session. The query can create tables, insert data, or query existing data.

Arguments

• query - The SQL query string to execute
• query_args - Optional array of query arguments (e.g., output format)

Returns

Returns a QueryResult containing the query output, or an Error if the query fails.

Examples

use chdb_rust::session::SessionBuilder;
use chdb_rust::arg::Arg;
use chdb_rust::format::OutputFormat;

let session = SessionBuilder::new()
    .with_data_path("/tmp/mydb")
    .with_auto_cleanup(true)
    .build()?;

// Create a table
session.execute(
    "CREATE TABLE test (id UInt64) ENGINE = MergeTree() ORDER BY id",
    None
)?;

// Query with JSON output
let result = session.execute(
    "SELECT * FROM test",
    Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)])
)?;

Errors

Returns an error if:

• The query syntax is invalid
• The query references non-existent tables or columns
• The query execution fails for any other reason

Trait Implementations

impl Debug for Session

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for Session

fn drop(&mut self)

Executes the destructor for this type.