Ie, given a dataset object ds = DB[:transactions].where{updated_at > 1.day.ago} - no funny joins and stuff going on - how could I fetch the table name (:transactions) ?
If you want the first table in the dataset, you can use ds.first_source.
If you want it as a string you can do:
ds.first_source_table.to_s
If you want a symbol, just omit .to_s
Based on the example provided, I would do something like this.
ds.klass.name
That will return a string with the name of your table.
lets say I have 7 columns in table, and I want to select only two of them, something like this
SELECT `name`,`surname` FROM `table` WHERE `id` = '1';
In laravel eloquent model it may looks like this
Table::where('id', 1)->get();
but I guess this expression will select ALL columns where id equals 1, and I want only two columns(name, surname). how to select only two columns?
You can do it like this:
Table::select('name','surname')->where('id', 1)->get();
Table::where('id', 1)->get(['name','surname']);
You can also use find() like this:
ModelName::find($id, ['name', 'surname']);
The $id variable can be an array in case you need to retrieve multiple instances of the model.
By using all() method we can select particular columns from table like as shown below.
ModelName::all('column1', 'column2', 'column3');
Note: Laravel 5.4
You first need to create a Model, that represent that Table and then use the below Eloquent way to fetch the data of only 2 fields.
Model::where('id', 1)
->pluck('name', 'surname')
->all();
Also Model::all(['id'])->toArray() it will only fetch id as array.
Get value of one column:
Table_Name::find($id)->column_name;
you can use this method with where clause:
Table_Name::where('id',$id)->first()->column_name;
or use this method for bypass PhpStorm "Method where not found in App\Models":
Table_Name::query()->where('id','=',$id)->first()->column_name;
in query builder:
DB::table('table_names')->find($id)->column_name;
with where cluase:
DB::table('table_names')->where('id',$id)->first()->column_name;
or
DB::table('table_names')->where('id',$id)->first('column_name');
last method result is array
You can use get() as well as all()
ModelName::where('a', 1)->get(['column1','column2']);
From laravel 5.3 only using get() method you can get specific columns of your table:
YouModelName::get(['id', 'name']);
Or from laravel 5.4 you can also use all() method for getting the fields of your choice:
YourModelName::all('id', 'name');
with both of above method get() or all() you can also use where() but syntax is different for both:
Model::all()
YourModelName::all('id', 'name')->where('id',1);
Model::get()
YourModelName::where('id',1)->get(['id', 'name']);
To get the result of specific column from table,we have to specify the column name.
Use following code : -
$result = DB::Table('table_name')->select('column1','column2')->where('id',1)->get();
for example -
$result = DB::Table('Student')->select('subject','class')->where('id',1)->get();
use App\Table;
// ...
Table::where('id',1)->get('name','surname');
if no where
Table::all('name','surname');
If you want to get a single value from Database
Model::where('id', 1)->value('name');
Also you can use pluck.
Model::where('id',1)->pluck('column1', 'column2');
You can use Table::select ('name', 'surname')->where ('id', 1)->get ().
Keep in mind that when selecting for only certain fields, you will have to make another query if you end up accessing those other fields later in the request (that may be obvious, just wanted to include that caveat). Including the id field is usually a good idea so laravel knows how to write back any updates you do to the model instance.
You can get it like
`PostModel::where('post_status', 'publish')->get(['title', 'content', 'slug', 'image_url']`)
link
you can also used findOrFail() method here it's good to used
if the exception is not caught, a 404 HTTP response is automatically sent back to the user. It is not necessary to write explicit checks to return 404 responses when using these method not give a 500 error..
ModelName::findOrFail($id, ['firstName', 'lastName']);
While most common approach is to use Model::select,
it can cause rendering out all attributes defined with accessor methods within model classes. So if you define attribute in your model:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class User extends Model
{
/**
* Get the user's first name.
*
* #param string $value
* #return string
*/
public function getFirstNameAttribute($value)
{
return ucfirst($value);
}
}
And then use:
TableName::select('username')->where('id', 1)->get();
It will output collection with both first_name and username, rather than only username.
Better use pluck(), solo or optionally in combination with select - if you want specific columns.
TableName::select('username')->where('id', 1)->pluck('username');
or
TableName::where('id', 1)->pluck('username'); //that would return collection consisting of only username values
Also, optionally, use ->toArray() to convert collection object into array.
If you want to get single row and from the that row single column, one line code to get the value of the specific column is to use find() method alongside specifying of the column that you want to retrieve it.
Here is sample code:
ModelName::find($id_of_the_record, ['column_name'])->toArray()['column_name'];
If you need to get one column calling pluck directly on a model is the most performant way to retrieve a single column from all models in Laravel.
Calling get or all before pluck will read all models into memory before plucking the value.
Users::pluck('email');
->get() much like ->all() (and ->first() etc..) can take the fields you want to bring back as parameters;
->get/all(['column1','column2'])
Would bring back the collection but only with column1 and column2
You can use the below query:
Table('table')->select('name','surname')->where('id',1)->get();
If you wanted to get the value of a single column like 'name', you could also use the following:
Table::where('id', 1)->first(['name'])->name;
For getting multiple columns (returns collection) :
Model::select('name','surname')->where('id', 1)->get();
If you want to get columns as array use the below code:
Model::select('name','surname')->where('id', 1)->get()->toArray();
If you want to get a single column try this:
Model::where('id', 1)->first(['column_name'])->column_name;
i want to ask
is there any simplest way to make prefix like A001,A002,A003
when inserted to database with grocery CRUD ?
thanks in advance
Yes, you could use the callback_before_insert (See here) and then write a callback function to prepend the relevant field value with your A001, A002 etc. The field values will be in the $post_array array so for instance you would:
function prepend_callback($post_array) {
$post_array['my_field'] = 'A001' . $post_array['my_field'];
$post_array['my_other_field'] = 'A002' . $post_array['my_other_field'];
return $post_array;
}
I have an array of made up of type BSON::ObjectId and I want it to compare against some IDs as strings.
if my_array_of_BSON_ObjectIds.include?(#my_id_as_a_string)
# delete the item from the array
else
# add the item to the array as a BSON::ObjectId
end
This is not working as the types are different, can I turn my string into a BSON::ObjectId? If so, how?
Mongoid 2.x with 10gen's driver:
BSON::ObjectId.new('506144650ed4c08d84000001')
Mongoid 3 with moped:
Moped::BSON::ObjectId.from_string('506144650ed4c08d84000001')
Mongoid 4 (moped) / Mongoid 5/6/7 (mongo):
BSON::ObjectId.from_string('506144650ed4c08d84000001')
You can use BSON::ObjectId(#my_id_as_a_string) for representation your id as BSON::ObjectId
refs http://api.mongodb.org/ruby/current/BSON.html#ObjectId-class_method
collection.delete_one({"_id"=>BSON::ObjectId(params['id'])})
This worked for me and it deleted the record from the database successfully
There's a shorter way:
BSON::ObjectId("id_here")
but for your case it would be easier to simply map the objects to ids before the comparison:
if my_array_of_BSON_ObjectIds..map(&:to_s).include?(#my_id_as_a_string)