diff --git a/tests/examples.rs b/tests/examples.rs
index ccc6aea..0e09005 100644
--- a/tests/examples.rs
+++ b/tests/examples.rs
@@ -1,3 +1,9 @@
+//! Test examples for chdb-rust
+//!
+//! Note: These tests may fail when run in parallel due to connection resource contention
+//! in the chDB library. Run with `RUST_TEST_THREADS=1 cargo test --test examples`
+//! to ensure reliable execution.
+
 use chdb_rust::arg::Arg;
 use chdb_rust::error::Result;
 use chdb_rust::execute;
@@ -5,6 +11,7 @@ use chdb_rust::format::InputFormat;
 use chdb_rust::format::OutputFormat;
 use chdb_rust::log_level::LogLevel;
 use chdb_rust::session::SessionBuilder;
+use std::fs;
 
 #[test]
 fn test_stateful() -> Result<()> {
@@ -79,3 +86,362 @@ fn test_sql_syntax_error() {
     let result = execute("aaa", Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]));
     assert!(result.is_err(), "Expected error for invalid SQL");
 }
+
+#[test]
+fn test_output_formats() -> Result<()> {
+    let query = "SELECT 1 AS a, 'test' AS b, 3.14 AS pi";
+
+    // Test JSONEachRow
+    let result = execute(
+        query,
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+    let json_output = result.data_utf8_lossy();
+    assert!(json_output.contains("\"a\":1"));
+    assert!(json_output.contains("\"b\":\"test\""));
+
+    // Test CSVWithNames
+    let result = execute(
+        query,
+        Some(&[Arg::OutputFormat(OutputFormat::CSVWithNames)]),
+    )?;
+    let csv_output = result.data_utf8_lossy();
+    // CSV format may have quotes or different formatting, so check for key elements
+    assert!(csv_output.contains("a") && csv_output.contains("b") && csv_output.contains("pi"));
+    assert!(csv_output.contains("1") && csv_output.contains("test"));
+    assert!(!csv_output.is_empty());
+
+    // Test Pretty format
+    let result = execute(
+        query,
+        Some(&[Arg::OutputFormat(OutputFormat::Pretty)]),
+    )?;
+    let pretty_output = result.data_utf8_lossy();
+    assert!(!pretty_output.is_empty());
+
+    // Test TabSeparated (default)
+    let result = execute(query, None)?;
+    let ts_output = result.data_utf8_lossy();
+    assert!(ts_output.contains("1"));
+    assert!(ts_output.contains("test"));
+
+    Ok(())
+}
+
+#[test]
+fn test_query_result_statistics() -> Result<()> {
+    let result = execute(
+        "SELECT number FROM numbers(100)",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+
+    // Check that we read rows
+    assert!(result.rows_read() > 0);
+    assert_eq!(result.rows_read(), 100);
+
+    // Check that we read bytes
+    assert!(result.bytes_read() > 0);
+
+    // Check elapsed time (should be very small but >= 0)
+    let elapsed = result.elapsed();
+    assert!(elapsed.as_secs_f64() >= 0.0);
+
+    // Check data is not empty
+    let data = result.data_utf8_lossy();
+    assert!(!data.is_empty());
+    assert!(data.contains("\"number\":0"));
+    assert!(data.contains("\"number\":99"));
+
+    Ok(())
+}
+
+#[test]
+fn test_query_result_data_methods() -> Result<()> {
+    let result = execute(
+        "SELECT 'Hello, World!' AS greeting",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+
+    // Test data_utf8_lossy
+    let lossy = result.data_utf8_lossy();
+    assert!(lossy.contains("Hello, World!"));
+
+    // Test data_utf8 (should work for valid UTF-8)
+    let result = execute(
+        "SELECT 'Hello, World!' AS greeting",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+    let utf8 = result.data_utf8()?;
+    assert!(utf8.contains("Hello, World!"));
+
+    // Test data_ref
+    let result = execute(
+        "SELECT 'Hello' AS msg",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+    let bytes = result.data_ref();
+    assert!(!bytes.is_empty());
+    assert!(bytes.len() > 0);
+
+    Ok(())
+}
+
+#[test]
+fn test_multiple_inserts_and_aggregation() -> Result<()> {
+    let tmp = tempdir::TempDir::new("chdb-rust")?;
+    let session = SessionBuilder::new()
+        .with_data_path(tmp.path())
+        .with_auto_cleanup(true)
+        .build()?;
+
+    session.execute("CREATE DATABASE testdb; USE testdb", Some(&[Arg::MultiQuery]))?;
+
+    session.execute(
+        "CREATE TABLE products (id UInt64, name String, price Float64) \
+         ENGINE = MergeTree() ORDER BY id",
+        None,
+    )?;
+
+    // Insert multiple rows
+    session.execute(
+        "INSERT INTO products VALUES \
+         (1, 'Apple', 1.50), \
+         (2, 'Banana', 0.75), \
+         (3, 'Orange', 2.00), \
+         (4, 'Apple', 1.50)",
+        None,
+    )?;
+
+    // Test aggregation
+    let result = session.execute(
+        "SELECT name, COUNT(*) AS count, SUM(price) AS total, AVG(price) AS avg_price \
+         FROM products GROUP BY name ORDER BY name",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+
+    let output = result.data_utf8_lossy();
+    assert!(output.contains("Apple"));
+    assert!(output.contains("Banana"));
+    assert!(output.contains("Orange"));
+    assert_eq!(result.rows_read(), 3);
+
+    // Test filtering
+    let result = session.execute(
+        "SELECT COUNT(*) FROM products WHERE price > 1.0",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+    assert!(result.data_utf8_lossy().contains("\"COUNT()\":3"));
+
+    Ok(())
+}
+
+#[test]
+fn test_different_data_types() -> Result<()> {
+    let tmp = tempdir::TempDir::new("chdb-rust")?;
+    let session = SessionBuilder::new()
+        .with_data_path(tmp.path())
+        .with_auto_cleanup(true)
+        .build()?;
+
+    session.execute("CREATE DATABASE testdb; USE testdb", Some(&[Arg::MultiQuery]))?;
+
+    session.execute(
+        "CREATE TABLE types_test (
+            id UInt64,
+            name String,
+            age UInt8,
+            salary Float64,
+            active Bool,
+            created Date
+        ) ENGINE = MergeTree() ORDER BY id",
+        None,
+    )?;
+
+    session.execute(
+        "INSERT INTO types_test VALUES \
+         (1, 'Alice', 30, 50000.5, true, '2024-01-01'), \
+         (2, 'Bob', 25, 45000.0, false, '2024-01-02')",
+        None,
+    )?;
+
+    let result = session.execute(
+        "SELECT * FROM types_test ORDER BY id",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+
+    let output = result.data_utf8_lossy();
+    assert!(output.contains("\"id\":1"));
+    assert!(output.contains("\"name\":\"Alice\""));
+    assert!(output.contains("\"age\":30"));
+    assert!(output.contains("\"active\":true"));
+    assert_eq!(result.rows_read(), 2);
+
+    Ok(())
+}
+
+#[test]
+fn test_error_handling_table_not_found() {
+    let result = execute(
+        "SELECT * FROM nonexistent_table_12345",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    );
+    assert!(result.is_err(), "Expected error for non-existent table");
+
+    if let Err(e) = result {
+        match e {
+            chdb_rust::error::Error::QueryError(_) => {
+                assert!(true);
+            },
+            _ => {
+                panic!("Expected QueryError, got {:?}", e);
+            }
+        }
+    }
+}
+
+#[test]
+fn test_error_handling_invalid_syntax() {
+    let result = execute(
+        "SELECT * FROM WHERE invalid",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    );
+    assert!(result.is_err(), "Expected error for invalid SQL syntax");
+}
+
+#[test]
+fn test_session_auto_cleanup() -> Result<()> {
+    let tmp = tempdir::TempDir::new("chdb-rust")?;
+    let data_path = tmp.path().to_path_buf();
+    
+    {
+        let session = SessionBuilder::new()
+            .with_data_path(&data_path)
+            .with_auto_cleanup(true)
+            .build()?;
+
+        session.execute("CREATE DATABASE testdb; USE testdb", Some(&[Arg::MultiQuery]))?;
+        session.execute(
+            "CREATE TABLE test (id UInt64) ENGINE = MergeTree() ORDER BY id",
+            None,
+        )?;
+        session.execute("INSERT INTO test VALUES (1)", None)?;
+        
+        // Session should exist and work
+        let result = session.execute("SELECT COUNT(*) FROM test", None)?;
+        assert_eq!(result.rows_read(), 1);
+
+        // Check the folder was created
+        assert!(fs::metadata(&data_path).is_ok());
+    } // Session dropped here, auto_cleanup should trigger
+    
+    // Check the folder was deleted
+    assert!(fs::metadata(&data_path).is_err());
+
+    Ok(())
+}
+
+#[test]
+fn test_complex_query_with_joins() -> Result<()> {
+    let tmp = tempdir::TempDir::new("chdb-rust")?;
+    let session = SessionBuilder::new()
+        .with_data_path(tmp.path())
+        .with_auto_cleanup(true)
+        .build()?;
+
+    session.execute("CREATE DATABASE testdb; USE testdb", Some(&[Arg::MultiQuery]))?;
+
+    // Create orders table
+    session.execute(
+        "CREATE TABLE orders (id UInt64, customer_id UInt64, total Float64) \
+         ENGINE = MergeTree() ORDER BY id",
+        None,
+    )?;
+
+    // Create customers table
+    session.execute(
+        "CREATE TABLE customers (id UInt64, name String) \
+         ENGINE = MergeTree() ORDER BY id",
+        None,
+    )?;
+
+    session.execute(
+        "INSERT INTO customers VALUES (1, 'Alice'), (2, 'Bob')",
+        None,
+    )?;
+
+    session.execute(
+        "INSERT INTO orders VALUES (1, 1, 100.0), (2, 1, 50.0), (3, 2, 75.0)",
+        None,
+    )?;
+
+    // Test join query
+    let result = session.execute(
+        "SELECT c.name, COUNT(o.id) AS order_count, SUM(o.total) AS total_spent \
+         FROM customers c \
+         LEFT JOIN orders o ON c.id = o.customer_id \
+         GROUP BY c.name \
+         ORDER BY c.name",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+
+    let output = result.data_utf8_lossy();
+    assert!(output.contains("Alice"));
+    assert!(output.contains("Bob"));
+    assert_eq!(result.rows_read(), 2);
+
+    Ok(())
+}
+
+#[test]
+fn test_numbers_function() -> Result<()> {
+    // Test ClickHouse numbers() function
+    let result = execute(
+        "SELECT number, number * 2 AS doubled FROM numbers(10) WHERE number < 5",
+        Some(&[Arg::OutputFormat(OutputFormat::JSONEachRow)]),
+    )?;
+
+    assert_eq!(result.rows_read(), 5);
+    let output = result.data_utf8_lossy();
+    assert!(output.contains("\"number\":0"));
+    assert!(output.contains("\"number\":4"));
+    assert!(output.contains("\"doubled\":0"));
+    assert!(output.contains("\"doubled\":8"));
+
+    Ok(())
+}
+
+#[test]
+fn test_default_output_format() -> Result<()> {
+    // Test that default format (TabSeparated) works
+    let result = execute("SELECT 1 AS a, 'test' AS b", None)?;
+    let output = result.data_utf8_lossy();
+    assert!(!output.is_empty());
+    assert!(output.contains("1"));
+    assert!(output.contains("test"));
+
+    Ok(())
+}
+
+#[test]
+fn test_session_without_auto_cleanup() -> Result<()> {
+    let tmp = tempdir::TempDir::new("chdb-rust")?;
+    let session = SessionBuilder::new()
+        .with_data_path(tmp.path())
+        .with_auto_cleanup(false) // Explicitly disable cleanup
+        .build()?;
+
+    session.execute("CREATE DATABASE testdb; USE testdb", Some(&[Arg::MultiQuery]))?;
+    session.execute(
+        "CREATE TABLE test (id UInt64) ENGINE = MergeTree() ORDER BY id",
+        None,
+    )?;
+    session.execute("INSERT INTO test VALUES (1), (2), (3)", None)?;
+
+    let result = session.execute("SELECT COUNT(*) FROM test", None)?;
+    assert_eq!(result.rows_read(), 1);
+
+    // Check the folder was not deleted
+    assert!(fs::metadata(&tmp.path()).is_ok());
+
+    Ok(())
+}