The Grails Framework 6.0.0

(Quick Reference) ## indexColumn ### Purpose Customizes the index column definition of an indexed collection such as a `List` or `Map` ### Examples
    class Neo {

        static hasMany = [matrix: Integer]

        static mapping = {
            matrix indexColumn: [name: "the_matrix", type: Integer]
        }
    }
    def neo = new Neo()
    neo.matrix = [(1): 30, (2): 42, (3): 23]
    neo.save(flush: true)
### Description Usage: `association_name(indexColumn:map)` Arguments: `name` - The name of the column as a String `type` (optional) - The Hibernate type. `sqlType` (optional) - The underlying SQL type `enumType` (optional) - The enum type in for type-safe Enum properties. Either `ordinal` or `string`. `index` (optional) - The index name `unique` (optional) - Whether it is unique `length` (optional) - The length of the column `precision` (optional) - The precision of the column `scale` (optional) - The scale of the column By default when mapping an indexed collection such as a `Map` or `List` the index is stored in a column called `association_name_idx` which is an `integer` type in the case of lists and a String in the case of maps. You can alter how the index column is mapped using the `indexColumn` argument:
    static mapping = {
        matrix indexColumn: [name: "the_matrix", type: Integer]
    }
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