我正在做一个生成随机数据并用它填充 PostgreSQL 表的程序。您将找到我尝试执行三个简单 SQL 查询的代码。前两个查询效果很好,但第三个就不行。实际上,在第二次查询之后,我的一部分代码似乎根本没有执行,因为控制台中没有打印“是”。我试图通过注释掉第二个查询执行行来编译我的代码,然后执行我的代码的结尾。任何的想法?import java.sql.*;public class Main { public static void main(String[] args) { //connection to DB Class.forName("org.postgresql.Driver"); Connection con = DriverManager.getConnection("jdbc:postgresql://localhost:5432/Benerator","postgres","newPassword"); //print the first two columns of table bank_card_people PreparedStatement stmt = con.prepareStatement("select * from public.bank_card_people"); ResultSet res = stmt.executeQuery(); while(res.next()){ System.out.println(res.getString(1)+ " " + res.getString(2));} //add a line to the same table String SQL = "insert into public.bank_card_people (\"first-name\", \"last-name\", \"card-number\") VALUES ('example','example','example')"; PreparedStatement stmt2 = con.prepareStatement(SQL); stmt2.executeQuery(); // is supposed to print all the databases PreparedStatement stmt3 = con.prepareStatement("SELECT datname FROM pg_database WHERE datistemplate = false"); ResultSet res2 = stmt3.executeQuery(); System.out.println("yes"); while(res2.next()){ System.out.println(res2.getString(1));}这是输出:User OneUser TwoUser Threeexample exampleexample exampleNo results were returned by the query.这是我注释掉该行时的输出: stmt2.executeQuery();User OneUser TwoUser Threeexample exampleexample exampleyespostgresBenerator
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