one-to-many problem

From: Scott Anderson (sanderso..irvana.com)
Date: Mon May 12 2008 - 18:25:26 EDT

  • Next message: Mike Kienenberger: "Re: one-to-many problem"

    I've got a table `command which has:
            `id` int PK
            `name` varchar(32) UNIQUE

    and a table `command_alias` which has
            `alias` varchar(32) PK
            `name` varchar(32) FK REF `command`.`name`

    Take special note how `command_alias`.`name` is a FK to `command`.`name`
    (unique field) and not `command`.`id` (the PK)

    The following code chokes:
            public static CommandAlias create(Command command, String alias)
    {
                    CommandAlias ca =
    DatabaseContext.getContext().newObject(CommandAlias.class);
                    ca.setAlias(alias);
                    ca.setToCommand(command);
                    command.addToAliases(ca);
                    try {
                            ca.updateRow();
                            return ca;
                    } catch(Exception e) {
                            Out.exception(e);
                            return null;
                    }
            }

    With the error:

    May 12, 2008 6:15:55 PM org.apache.cayenne.access.QueryLogger logQuery
    INFO: INSERT INTO command_alias (alias, name) VALUES (?, ?)
    INFO: [batch bind: 1->alias:'aa', 2->name:NULL]
    May 12, 2008 6:15:55 PM org.apache.cayenne.access.QueryLogger
    logQueryError
    INFO: *** error.
    java.sql.SQLIntegrityConstraintViolationException: Column 'NAME' cannot
    accept a NULL value.

    I am 100% sure that I am not sending a null Command object. I believe
    this stems from the fact that the relationship is not a FK-PK
    relationship, but a FK-UNIQUE relationship, as evidenced by the fact
    that if I make the `command_alias`.`name` field visible in the code, and
    set do ca.setName(command.getName()) then this error does not occur.

    I am using a 3.0 snapshot from March.

    And here's the relevant sections of my mapping file (I removed some
    unrelated fields from command):

            <db-entity name="command">
                    <db-attribute name="id" type="INTEGER"
    isPrimaryKey="true" isGenerated="true" isMandatory="true" length="11"/>
                    <db-attribute name="name" type="VARCHAR"
    isMandatory="true" length="32"/>
            </db-entity>
            <db-entity name="command_alias">
                    <db-attribute name="alias" type="VARCHAR"
    isPrimaryKey="true" isMandatory="true" length="32"/>
                    <db-attribute name="name" type="VARCHAR" length="32"/>
            </db-entity>
            <obj-entity name="Command" className="net.bnubot.db.Command"
    dbEntityName="command" superClassName="net.bnubot.db.CustomDataObject">
                    <obj-attribute name="name" type="java.lang.String"
    db-attribute-path="name"/>
            </obj-entity>
            <obj-entity name="CommandAlias"
    className="net.bnubot.db.CommandAlias" dbEntityName="command_alias"
    superClassName="net.bnubot.db.CustomDataObject">
                    <obj-attribute name="alias" type="java.lang.String"
    db-attribute-path="alias"/>
            </obj-entity>
            <db-relationship name="commandAliasArray" source="command"
    target="command_alias" toMany="true">
                    <db-attribute-pair source="name" target="name"/>
            </db-relationship>
            <db-relationship name="toCommand" source="command_alias"
    target="command" toMany="false">
                    <db-attribute-pair source="name" target="name"/>
            </db-relationship>
            <obj-relationship name="aliases" source="Command"
    target="CommandAlias" deleteRule="Deny"
    db-relationship-path="commandAliasArray"/>
            <obj-relationship name="toCommand" source="CommandAlias"
    target="Command" db-relationship-path="toCommand"/>

    This archive was generated by hypermail 2.0.0 : Mon May 12 2008 - 18:26:30 EDT