JDBC语句接口 - executeUpdate查询

Question

import java.sql.*;
class ConnectionTest {
    public static void main(String... args)throws Exception {
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        Connection con = DriverManager.getConnection("Jdbc:Odbc:myjdbc1", "sri", "tiger");
        System.out.println(con);
        Statement st = con.createStatement();
        System.out.println(st);
        String query = "delete logindetails";
        int count = st.executeUpdate(query);
        if(count == 0) 
        System.out.println("no records to delete");
        else 
        System.out.println("deleted successfullly");
        con.close();
    }
}

Hello World..!! My Question is.. What value is being assigned to integer variable count in int count = st.executeUpdate(query);
What does it assigns after it deleted all the rows..
and what does it assigns if there are already 0 rows in my table and no rows are deleted..?

Detailed explanation is much appreciated.
PS noob here

Answer 1

From official docs : Returns: either the row count for SQL Data Manipulation Language (such as INSERT, UPDATE or DELETE) statements or 0 for SQL statements that return nothing

@Update

It assigns the number of deleted rows.

Answer 2

executeUpdate（query）返回受影响的行数，这意味着如果表中没有行，那么将返回0，如果表中有行，那么表的总行数。

Answer 3

Returns: either

(1) the row count for SQL Data Manipulation Language (DML) statements or

(2) 0 for SQL statements that return nothing