java - 无法使用 getImportedKeys() 或 getExportedKeys() 获取外键，只有 getPrimaryKeys() 有效

Question

我无法使用 getImportedKeys() 或 getExportedKeys() 从元数据中找到外键。数据库确实包含外键关系，并且 getPrimaryKey() 确实有效。我该如何解决这个问题？

DatabaseMetaData dbMeta = conn.getMetaData();
System.out.println("Foreign Keys are\n");
ResultSet rs = dbMeta.getExportedKeys("", "", "CUSTOMERS");
while (rs.next()) {
    //System.out.println(rs.getString("FKCOLUMN_NAME"));
    System.out.println(rs.getString("FK_NAME") + "\t" + rs.getString("FKCOLUMN_NAME"));
    }

Answer 1

尝试一下，看看它是否有效:)

private static void printForeignKeys(Connection connection, String CUSTOMERS) throws SQLException {
    System.out.println("Foreign Keys are\n");
    DatabaseMetaData dbMeta= connection.getMetaData();
    ResultSet foreignKeys = dbMeta.getImportedKeys(connection.getCatalog(), null, CUSTOMERS);
    while (foreignKeys.next()) {
        String fkName = foreignKeys.getString("FK_NAME");
        String fkColumnName = foreignKeys.getString("FKCOLUMN_NAME");
        System.out.println(fkName + "." + fkColumnName);
    }
}