how to import huge tsv file into h2 in memory database with spring boot - spring-boot

Question

I have a huge tsv files and I need to import them into my h2 in memory database.
I can read it with Scanner and import it line by line but it takes for hours !
is there any faster way to import tsv file into h2 in memory database ?

Answer 1

Use insert into select convert for direct importing from file into your h2 table.
How to read CSV file into H2 database :
public static void main (String [] args) throws Exception {
Connection conn = null;
Statement stmt = null;
Class.forName("org.h2.Driver");
conn = DriverManager.getConnection("jdbc:h2:~/test", "", "");
stmt = conn.createStatement();
stmt.execute("drop table if exists csvdata");
stmt.execute("create table csvdata (id int primary key, name varchar(100), age int)");
stmt.execute("insert into csvdata ( id, name, age ) select convert( \"id\",int ), \"name\", convert( \"age\", int) from CSVREAD( 'c:\\tmp\\sample.csv', 'id,name,age', null ) ");
ResultSet rs = stmt.executeQuery("select * from csvdata");
while (rs.next()) {
System.out.println("id " + rs.getInt("id") + " name " + rs.getString("name") + " age " + rs.getInt("age") );
}
stmt.close();
}
Or
SELECT * FROM CSVREAD('test.csv');
-- Read a file containing the columns ID, NAME with
SELECT * FROM CSVREAD('test2.csv', 'ID|NAME', 'charset=UTF-8 fieldSeparator=|');
SELECT * FROM CSVREAD('data/test.csv', null, 'rowSeparator=;');
-- Read a tab-separated file
SELECT * FROM CSVREAD('data/test.tsv', null, 'rowSeparator=' || CHAR(9));
SELECT "Last Name" FROM CSVREAD('address.csv');
SELECT "Last Name" FROM CSVREAD('classpath:/org/acme/data/address.csv');
h2 csvread function
NOTE: You can specify file's field separator for these commands.