How to set a default value for a column ?

[Vicky]

Is there a way to set a default value for a column when we create a table ?

I know that by default every column type has its own default value. But can we change it ?

[Arthur Hsu]

I don't believe this is a common SQL feature. You can fork and implement it yourself if you need it.

[dpa...@chromium.org]

You can also use a db.update() query to update all the columns to a new default value, after you get a connection to the DB.

db.update(myTable).
    set(order.column, newDefaultValue).
    where(order.column.eq(previousDefaultValue)).
    exec();

See more details at https://github.com/google/lovefield/blob/master/docs/spec/04_query.md#43-update-query-builder

On Friday, March 24, 2017 at 4:51:20 AM UTC-7, Vicky wrote:

[dpa...@chromium.org]

Correction

db.update(myTable).
    set(myTable.column, newDefaultValue).
    where(myTable.column.eq(previousDefaultValue)).
    exec();

[thusi...@gmail.com]

When we update records according to the above update query we always see the following error message in the console.

Error: http://google.github.io/lovefield/error_lookup/src/error_lookup.html?c=501

Please advise on any clue on how to resolve this.

[Arthur Hsu]

Error message said "Value is not bounded". Seems to me that your "newDefaultValue" is created by lf.bind and you did not bind proper value on it.

https://github.com/google/lovefield/blob/master/docs/spec/04_query.md#45-parameterized-query has information regarding how to do proper binding on parameterized query.

[thusi...@gmail.com]

var q = db.

update(p).

set(p._mode, lf.bind(1)).

where(p.seq.eq(lf.bind(0)));

q.bind([2, 1]).exec();

For the above simple update code we get the error message. But the strange thing is insert, delete and select expressions works without any issue.

Error message is not descriptive enough for us to dig deeper. Is it a DB lock sort of a thing? This is very critical for us to solve this issue.

Thanks.

Thusitha