java - 将值插入到引用另一个表的外键的 MySQL 表中

Question

我目前有以下查询，我想用它来插入两个字符串和一个外键。但是，当我传递外键的字符串时，我想在插入时获取 key ，以便记录实际上读取为:

“全亚洲 Assets Cp”、“AAA”、1

下面是我使用的字符串:

    String sql = "INSERT into constituent " + 
            "(constituent_name, constituent_ticker, sector_id) values (\""+ 
            constituent.getConstituentName() + "\",\"" +
            constituent.getConstituentTicker() + "\"," +
            "(select id from sector where sector_name = \"" + constituent.getConstituentSector() + "\"))";

下面是查询。

INSERT into constituent (constituent_name, constituent_ticker, sector_id) 
  values ("All Asia Asset Cp","AAA",
     (select sector.id from sector where sector_name = "General Financial Sector"))

但是，我收到以下错误，我很困惑。有什么想法吗？

Unknown column 'sector.id' in 'field list'

按原样在 phpMyAdmin 中运行查询是可行的。

使用以下代码从 java 运行它会引发错误:

    //Initialize insertValues
    insertValues = connect.prepareStatement(sql);

    //Attempt to add the values into the database
    try {
        insertValues.execute();
    } catch (Exception e) {

        Log.e(CLASS_NAME, "createConstituent ", e);

    }

扇区表的DDL:

CREATE TABLE `sector` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `sector_name` varchar(100) DEFAULT NULL,
  `sector_url` varchar(500) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=39 DEFAULT CHARSET=latin1;

对于成分表的DDL:

CREATE TABLE `constituent` (
  `constituent_id` int(11) NOT NULL AUTO_INCREMENT,
  `constituent_name` varchar(100) DEFAULT '',
  `constituent_ticker` varchar(10) NOT NULL,
  `constituent_isin_number` varchar(50) DEFAULT '',
  `constituent_currency` varchar(10) DEFAULT '',
  `sector_id` int(11) NOT NULL,
  PRIMARY KEY (`constituent_id`),
  KEY `sector_id` (`sector_id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=latin1;

Answer 1

您可以尝试仅使用 id 来代替扇区.id 吗？可以吗？

INSERT into constituent (constituent_name, constituent_ticker, sector_id) values ("All Asia Asset Cp","AAA",(select id from sector where sector_name = "General Financial Sector"))