我正在尝试使用SQLite-JDBC从 Java 中的 SQL 数据库读取数据,但是在向 a 填充参数PreparedStatement
时出现错误。代码的重要部分和错误如下。
Scanner scanner = new Scanner(System.in);
Connection db = DriverManager.getConnection("jdbc:sqlite:kurssit.db");
Statement s = db.createStatement();
PreparedStatement p;
p = db.prepareStatement("SELECT SUM(K.laajuus) "
+ "FROM Suoritukset S, Kurssit K "
+ "WHERE S.kurssi_id = K.id AND S.paivays LIKE '" + "?" + "%';");
p.setString(1, scanner.nextLine());
try {
ResultSet r = p.executeQuery();
System.out.println("Amount: " + r.getString(1));
} catch (SQLException e) {
System.out.println("Data not found.");
}
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0
at org.sqlite.core.CorePreparedStatement.batch(CorePreparedStatement.java:121)
at org.sqlite.jdbc3.JDBC3PreparedStatement.setString(JDBC3PreparedStatement.java:421)
at Main.main(Main.java:28)
C:\Users\user\AppData\Local\NetBeans\Cache\12.0\executor-snippets\run.xml:111: The following error occurred while executing this line:
C:\Users\user\AppData\Local\NetBeans\Cache\12.0\executor-snippets\run.xml:68: Java returned: 1
第 28 行,即错误所在的行,在这个缩短的代码版本中就是这样说的p.setString(1, scanner.nextLine());
。
//Imports
import java.sql.*;
import java.util.*;
提前谢谢了。