如何使用java命令在数据库中搜索？（How to search in the database using java commands?）

问题描述 (Problem Description)

如何搜索表格的内容？

解决方案 (Solution)

以下方法使用sql命令来搜索数据库。

import java.sql.*;
public class jdbcConn {
   public static void main(String[] args) throws Exception {
      Class.forName("org.apache.derby.jdbc.ClientDriver");
      Connection con = DriverManager.getConnection(
         "jdbc:derby://localhost:1527/testDb","username", "password");
      Statement stmt = con.createStatement();
      String query[] = {
         "SELECT * FROM emp where id = 1", 
         "select name from emp where name like 'ravi_'", 
         "select name from emp where name like 'ravi%'" 
      };
      for(String q : query) {
         ResultSet rs = stmt.executeQuery(q);
         System.out.println("Names for query "+q+" are");
         while (rs.next()) {
            String name = rs.getString("name");
            System.out.print(name+"  ");
         }
         System.out.println();
      }
   }
}

结果 (Result)

上面的代码示例将产生以下结果。结果可能会有所不同。

Names for query SELECT * FROM emp where id=1 are
ravi  
Names for query select name from emp where name like 'ravi_' are
ravi2  ravi3  
Names for query select name from emp where name like 'ravi%' are
ravi  ravi2  ravi3  ravi123  ravi222