can I set an alias for an aggregate field?

john dimm

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Jul 17, 2019, 1:22:03 AM7/17/19

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lf.fn.sum(myTable[column])

comes back as "SUM(myField)", which my code displays to the user. It would be nice to set an alias but

lf.fn.sum(this.fact[key]).as(key)

doesn't work.

Uncaught TypeError: lf.fn.sum(...).as is not a function

Is there a way?

Demetrios Papadopoulos

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Jul 17, 2019, 12:47:27 PM7/17/19

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This should in theory work. lf.fn.sum() returns an AggregatedColumn at [1], which supports as(), see [2]. There is also a test that uses lf.fn.count().as() at [3]. Are you sure that this.fact[key], returns a valid lovefield column?

If that does indeed not work, might be a bug, as aliasing aggregated columns is supported.

[1] https://github.com/google/lovefield/blob/6e6cc7cae1421a8da6d5e55ffecb0cdedf6b29a6/lib/fn.js#L108

[2] https://github.com/google/lovefield/blob/6e6cc7cae1421a8da6d5e55ffecb0cdedf6b29a6/lib/aggregated_column.js#L105

[3] https://github.com/google/lovefield/blob/master/tests/proc/end_to_end_select_tester.js#L1367

john dimm

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Jul 17, 2019, 1:40:41 PM7/17/19

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Since there is a test for count, I modified the quick start example to check.

The following produces the error:

lovefield.min.js:28 Uncaught TypeError: lf.fn.count(...).as is not a function

Comment out the line with "as" and uncomment the one below it to remove the error and get the count of 1 in the console.

Maybe my lovefield.min.js is bad? I tried the one from the codelab first, then the one in dist. Same error. The one from dist has 276 lines.

<!doctype html>

<html>

<head>

<meta charset="utf-8" />

<title>Minimal example of using Lovefield</title>

<script src="lib/lovefield.min.js"></script>

</head>

<body>

<script>

var schemaBuilder = lf.schema.create('todo', 1);

schemaBuilder.createTable('Item').

addColumn('id', lf.Type.INTEGER).

addColumn('description', lf.Type.STRING).

addColumn('deadline', lf.Type.DATE_TIME).

addColumn('done', lf.Type.BOOLEAN).

addPrimaryKey(['id']).

addIndex('idxDeadline', ['deadline'], false, lf.Order.DESC);

var todoDb;

var item;

schemaBuilder.connect().then(function(db) {

todoDb = db;

item = db.getSchema().table('Item');

var row = item.createRow({

'id': 1,

'description': 'Get a cup of coffee',

'deadline': new Date(),

'done': false

});

return db.insertOrReplace().into(item).values([row]).exec();

}).then(function() {

return todoDb.select(

lf.fn.count().as('count of rows')

// lf.fn.count()

).from(item).where(item.done.eq(false)).exec();

}).then(function(results) {

results.forEach(function(row) {

// console.log(row['description'], 'before', row['deadline']);

console.log(row['COUNT(*)']);

});

});

</script>

</body>

</html>

Demetrios Papadopoulos

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Jul 17, 2019, 1:43:33 PM7/17/19

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On Wednesday, July 17, 2019 at 10:40:41 AM UTC-7, john dimm wrote:

Since there is a test for count, I modified the quick start example to check.

The following produces the error:

  lovefield.min.js:28 Uncaught TypeError: lf.fn.count(...).as is not a function

Comment out the line with "as" and uncomment the one below it to remove the error and get the count of 1 in the console.

Maybe my lovefield.min.js is bad?

Thanks for the repro example. Can you try the non-minified version of lovefield? It should be lovefield.js in the same dist/ folder. Does it exhibit the same problem?

john dimm

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Jul 17, 2019, 2:41:52 PM7/17/19

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Woo hoo! That did it. No problem when using lovefield.js instead of lovefield.min.js.

Demetrios Papadopoulos

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Jul 17, 2019, 3:06:18 PM7/17/19

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On Wednesday, July 17, 2019 at 11:41:52 AM UTC-7, john dimm wrote:

Woo hoo! That did it. No problem when using lovefield.js instead of lovefield.min.js.

Cool! If you could file a bug on our bug tracker (https://github.com/google/lovefield/issues) about this not working in the minified version, it would be helpful.

Thanks!

john dimm

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Jul 17, 2019, 5:33:33 PM7/17/19

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Done.

On Wednesday, July 17, 2019 at 10:40:41 AM UTC-7, john dimm wrote:

john dimm

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Jul 20, 2019, 1:20:54 AM7/20/19

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The problem was really that I was using lovefield.min.js from the stock_analysis codelab. The current version works correctly, both normal and minified.

On Tuesday, July 16, 2019 at 10:22:03 PM UTC-7, john dimm wrote:

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