Hive - Drop Database

Hive - Drop Database - myTechMint

The usage of SCHEMA and DATABASE are same.

Drop Database Statement


Drop Database is a statement that drops all the tables and deletes the database. Its syntax is as follows:
DROP DATABASE StatementDROP (DATABASE|SCHEMA) [IF EXISTS] database_name 
[RESTRICT|CASCADE];

The following queries are used to drop a database. Let us assume that the database name is userdb.
hive> DROP DATABASE IF EXISTS userdb;

The following query drops the database using CASCADE. It means dropping respective tables before dropping the database.
hive> DROP DATABASE IF EXISTS userdb CASCADE;

The following query drops the database using SCHEMA.
hive> DROP SCHEMA userdb;

This clause was added in Hive 0.6.

JDBC Program


The JDBC program to drop a database is given below.
import java.sql.SQLException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.DriverManager;

public class HiveDropDb {
private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver";

public static void main(String[] args) throws SQLException {

// Register driver and create driver instance
Class.forName(driverName);

// get connection
Connection con = DriverManager.getConnection("jdbc:hive://localhost:10000/default", "", "");
Statement stmt = con.createStatement();
stmt
.executeQuery("DROP DATABASE userdb");

System.out.println(“Drop userdb database successful.”);

con
.close();
}
}

Save the program in a file named HiveDropDb.java. Given below are the commands to compile and execute this program.
$ javac HiveDropDb.java
$ java
HiveDropDb

Output:


Drop userdb database successful.

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