README.md

Databend JDBC

Prerequisites

The Databend JDBC driver requires Java 8 or later. If the minimum required version of Java is not installed on the client machines where the JDBC driver is installed, you must install either Oracle Java or OpenJDK.

Installation

Maven

Add following code block as a dependency

<dependency>
    <groupId>com.databend</groupId>
    <artifactId>databend-jdbc</artifactId>
    <version>0.3.2</version>
</dependency>

Build from source

cd databend-jdbc
mvn clean install -DskipTests

Download jar from maven central

You can download the latest version of the databend-jdbc driver [here](https://repo1.maven.org/maven2/com/databend/databend-jdbc/).

How to use

import java.sql.SQLException;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSet;

public class Main {
    public static void main(String[] args) throws SQLException {
        Connection conn = DriverManager.getConnection("jdbc:databend://localhost:8000", "root", "");
        Statement statement = conn.createStatement();
        statement.execute("SELECT number from numbers(200000) order by number");
        ResultSet r = statement.getResultSet();
        // ** We must call `rs.next()` otherwise the query may be canceled **
        while (rs.next()) {
            System.out.println(r.getInt(1));
        }
        conn.close();
    }
}

Important Notes

1. Because the select, copy into, merge into are query type SQL, they will return a ResultSet object, you must call rs.next() before accessing the data. Otherwise, the query may be canceled. If you do not want get the result, you can call while(r.next(){}) to iterate over the result set.
2. For other SQL such as create/drop table non-query type SQL, you can call statement.execute() directly.

JDBC Java type mapping

The Databend type is mapped to Java type as follows:

Databend Type	Java Type
TINYINT	Byte
SMALLINT	Short
INT	Integer
BIGINT	Long
UInt8	Short
UInt16	Integer
UInt32	Long
UInt64	BigInteger
Float32	Float
Float64	Double
String	String
Date	String
TIMESTAMP	String
Bitmap	byte[]
Array	String
Decimal	BigDecimal
Tuple	String
Map	String
VARIANT	String

For detailed references, please take a look at the following Links:

1. Connection Parameters : detailed documentation about how to use connection parameters in a jdbc connection