Grails域类中的字符串列表 [英] List of Strings in a Grails domain class
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问题描述
我试图在Grails域类的MySql中使用 String 的 List 。 p>
我试过以下内容：
class Catalog {
List books
String book
static hasMany = [books：book]
}
和
class Catalog {
List books
class Catalog {
String [] books
}
pre>
和
class Catalog {
ArrayList< String> books = new ArrayList< String>（）
}
编译但该条目不存在于MySQL中。
在MySQL中没有表或列来表示这些数据，我试图用数据填充数组。仍然没有。
有什么想法？
解决方案通过使用 hasMany 。此外，您需要将 books 定义为 List ，因为没有它，您会得到一个简单的 Set
class Catalog {
static hasMany = [books ：String]
List books
}
I am trying to have a List of String that works in MySql in a Grails domain class.
I have tried the following:
class Catalogue {
List books
String book
static hasMany = [books: book]
}
and
class Catalogue {
List books
}
and
class Catalogue {
String[] books
}
and
class Catalogue {
ArrayList<String> books = new ArrayList<String>()
}
The last three compiles but the entry is not present in MySQL.
There is no table, or column to represent this data in MySQL and I have tried populating the array with data. Still nothing.
Any ideas?
解决方案 You can achieve this by using hasMany. Furthermore you need to define books as a List since without it you would get a simple Set that does not allow any duplicates.
class Catalogue {
static hasMany = [books: String]
List books
}
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