Mysql – Angular 2 and MySQL concepts

angularMySQL

Are there recommended concepts how to access MySQL from an Angular 2 application?

I'm new to Angular and Typescript. I found and installed the node-mysql package. I would like to SELECT some datasets for computational analysis and some graphical representation (perhaps with d3).

My own concept would be to implement a singleton service encapsulating the connection and SQL calls.

But perhaps I am thinking too old school here? Perhaps there should be a different approach?

On the practical side, I'm uncertain how to import the node-mysql package in Angular2 / Typescript – by importing the package at the top?

If someone could point me to an example, I'd be glad to learn.

Best Answer

Communication directly from Angular to Mysql is bad practice (in most cases). Angular runs client side and exposing mysql to it allows for anybody to run arbitrary SQL statements.

The solution is to create an intermidate server. It could run nodejs, to which you can then import node-mysql. The nodejs server could expose a REST api which your angular 2 application consumes.

Related Solutions

Mysql – concatenate multiple MySQL rows into one field

You can use GROUP_CONCAT:

SELECT person_id,
   GROUP_CONCAT(hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Ludwig stated in his comment, you can add the DISTINCT operator to avoid duplicates:

SELECT person_id,
   GROUP_CONCAT(DISTINCT hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Jan stated in their comment, you can also sort the values before imploding it using ORDER BY:

SELECT person_id, 
       GROUP_CONCAT(hobbies ORDER BY hobbies ASC SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;

As Dag stated in his comment, there is a 1024 byte limit on the result. To solve this, run this query before your query:

SET group_concat_max_len = 2048;

Of course, you can change 2048 according to your needs. To calculate and assign the value:

SET group_concat_max_len = CAST(
                     (SELECT SUM(LENGTH(hobbies)) + COUNT(*) * LENGTH(', ')
                           FROM peoples_hobbies
                           GROUP BY person_id) AS UNSIGNED);

Mysql – Which MySQL data type to use for storing boolean values

For MySQL 5.0.3 and higher, you can use BIT. The manual says:

As of MySQL 5.0.3, the BIT data type is used to store bit-field values. A type of BIT(M) enables storage of M-bit values. M can range from 1 to 64.

Otherwise, according to the MySQL manual you can use BOOL or BOOLEAN, which are at the moment aliases of tinyint(1):

Bool, Boolean: These types are synonyms for TINYINT(1). A value of zero is considered false. Non-zero values are considered true.

MySQL also states that:

We intend to implement full boolean type handling, in accordance with standard SQL, in a future MySQL release.

References: http://dev.mysql.com/doc/refman/5.5/en/numeric-type-overview.html

Best Answer

Related Solutions

Mysql – concatenate multiple MySQL rows into one field

Mysql – Which MySQL data type to use for storing boolean values

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