Building Queries

As demonstrated before, Leaf Db allows you to perfectly write SQL queries, however, it also provides simpler and more convenient methods for building queries. This means that you won't need to write any SQL statements.

create

This method allows you build a query to create a database.

db()->create('dbname')->execute();

$db->create('dbname')->execute();

drop

This method helps you build a query to drop a database.

db()->drop('dbname')->execute();

$db->drop('dbname')->execute();

select

This is a method for quickly building select statements. The SELECT statement is used to select data from a database.

It takes in 2 parameters:

The table to select items from
The columns to include (includes all by default)

// returns all items
$items = db()->select('items')->all();

// returns the username & email of all buyers
$buyers = db()->select("buyers", "username, email")->fetchAll();

// returns all items
$items = $db->select('items')->all();

// returns the username & email of all buyers
$buyers = $db->select("buyers", "username, email")->fetchAll();

where

The where method allows you to quickly write a where block.

$user = db()
  ->select("users")
  ->where("username", "mychi")
  ->first();

$user = $db
  ->select("users")
  ->where("username", "mychi")
  ->first();

You can also pass in a bunch of params to check for:

$user = db()
  ->select("users")
  ->where([
    "username" => "mychi",
    "password" => "..."
  ])
  ->first();

$user = $db
  ->select("users")
  ->where([
    "username" => "mychi",
    "password" => "..."
  ])
  ->first();

Comparators

v2 of leaf db introduces a third parameter to the where and orWhere blocks. This allows you to check how a value compares to another using =, LIKE, >, ...

db()
  ->select('items')
  ->where('tag', 'LIKE', '%new%')
  ->fetchAll();

$db
  ->select('items')
  ->where('tag', 'LIKE', '%new%')
  ->fetchAll();

orWhere

orWhere also functions just like where, except that in the case of multiple parameters, orWhere returns results even if one of the conditions is met, but where only returns results if all the conditions are matched.

$users = db()
  ->select("users")
  ->orWhere([
    "username" => "mychi",
    "username" => "darko"
  ])
  ->all();

$users = $db
  ->select("users")
  ->orWhere([
    "username" => "mychi",
    "username" => "darko"
  ])
  ->all();

Kind of like SELECT * FROM users WHERE username = 'mychi' OR username = 'darko'

Chaining

You can chain where and orWhere blocks together to make queries that use AND and OR operators.

db()
  ->select('users')
  ->where('username', 'mychi')
  ->orWhere('username', 'darko')
  ->first();

$db
  ->select('users')
  ->where('username', 'mychi')
  ->orWhere('username', 'darko')
  ->first();

This query will look for a username which is either mychi or darko and return whichever it finds first.

find

This method allows you to quickly perform a check for the id key on a table. It takes in 1 parameter which is the id of the row to get.

$user = db()->select("users")->find(1);

$user = $db->select("users")->find(1);

Note

Find returns the value it finds immediately, so you should not use fetchAssoc or any other fetch method on the value returned.

Table operations

table

table sets the table pointer for the db table being used. table can be combined with other methods like search.

db()->table("items");

$db->table("items");

search

Just as the name implies, you can use this method to search for a value in the database table. It is used with the table method.

$res = db()->table("items")->search("name", "chocola");

$res = $db->table("items")->search("name", "chocola");

This will try to find an item which has chocola in it's name field.

insert

Insert provides a much simpler syntax for making insert queries.

db()->insert("users") // faster than db()->query("INSERT INTO users")

$db->insert("users") // faster than db()->query("INSERT INTO users")

params

This method is used on insert and update just like how where is used on select and delete.

db()->insert("users")->params(["username" => "mychi"]);

$db->insert("users")->params(["username" => "mychi"]);

To actually run this query, you have to call execute.

db()->insert("users")->params(["username" => "mychi"])->execute();

$db->insert("users")->params(["username" => "mychi"])->execute();

This inserts a user with a username of mychi into the users table. But what if you wanted to add more params, simple!

db()
  ->insert("users")
  ->params([
    "username" => "mychi",
    "email" => "mickdd22@gmail.com"
  ])
  ->execute();

$db
  ->insert("users")
  ->params([
    "username" => "mychi",
    "email" => "mickdd22@gmail.com"
  ])
  ->execute();

You're free to arrange this query anyhow you see fit, it's still considered as a single chain.

db()
  ->insert("users")
   ->params([
     "username" => "mychi",
     "email" => "mickdd22@gmail.com",
     "password" => Leaf\Password::hash("test")
   ])
   ->execute();

$db
  ->insert("users")
   ->params([
     "username" => "mychi",
     "email" => "mickdd22@gmail.com",
     "password" => Leaf\Password::hash("test")
   ])
   ->execute();

What if you already registered someone with the username mychi, this tiny flaw could break your authentication system. That's where unique comes in🧐

unique

Just as the name implies, unique helps prevent duplicates in your database, fun fact, just chain one more method for this functionality

db()
  ->insert("users")
  ->params([
    "username" => "mychi",
    "email" => "mickdd22@gmail.com",
    "password" => hash("test")
   ])
   ->unique("username", "email")
   ->execute();

$db
  ->insert("users")
  ->params([
    "username" => "mychi",
    "email" => "mickdd22@gmail.com",
    "password" => hash("test")
   ])
   ->unique("username", "email")
   ->execute();

If you have a 100 unique values, don't feel shy, just line them all up.

->unique("username", "email", "what-not", ...)

Alternatively, you could just pack a truck load full of uniques in an array

->unique(["username", "email", "what-not", ...])

update

Quickly write an update query.

db()
  ->update("users")
  ->params(["location" => "Ghana"])
  ->where("id", "1")
  ->execute();

$db
  ->update("users")
  ->params(["location" => "Ghana"])
  ->where("id", "1")
  ->execute();

This is generally how an update looks like. Just like with insert, you can add up uniques to make sure you don't have duplicates in your database.

you can chain in unique here as well.

delete

Let's jump straight in for an example.

db()->delete("users")->execute(); // careful now 🙂

$db->delete("users")->execute(); // careful now 🙂

Watch out

Be careful when running delete queries without a where block. Doing that will wipe that whole table.

db()->delete("users")->where("id", "1")->execute();

$db->delete("users")->where("id", "1")->execute();

You have succesfully deleted user 1

Extras

hidden

Not all information which is retrieved from the database is sent over to the client side or is added to the session or cookies. Usually, some fields are left out for "security" reasons. hidden returns the retrieved data without the hidden fields.

db()
  ->select("users")
  ->hidden("remember_token", "reset_q_id")
  ->fetchAll();

$db
  ->select("users")
  ->hidden("remember_token", "reset_q_id")
  ->fetchAll();

db()
  ->select("users")
  ->where("id", "1")
  ->hidden("remember_token", "reset_q_id")
  ->fetchObj();

$db
  ->select("users")
  ->where("id", "1")
  ->hidden("remember_token", "reset_q_id")
  ->fetchObj();

add

That's right, just imagine doing the opposite of hidden, instead of hiding fields from the query data, add lets you add your own fields into the query data.

NOTE

This does not touch your database, it only appends a field into the data returned from the database.

db()
  ->select("users")
  ->add("tx_id", gID())
  ->fetchAll();

$db
  ->select("users")
  ->add("tx_id", gID())
  ->fetchAll();

This query adds a tx_id field with a value generated from gID to every user

db()
  ->select("users")
  ->where("id", "1")
  ->add("tx_id", "d362d7t2366")
  ->fetchObj();

$db
  ->select("users")
  ->where("id", "1")
  ->add("tx_id", "d362d7t2366")
  ->fetchObj();

This is similar as the query above, except that this query is on the scale of a single user.

bind

We've already seen bind in action, but we've not actually talked about it. This method allows you to bind parameters into your query.

db()
  ->select("users WHERE username = ?")
  ->bind("mychi")
  ->fetchAssoc();

$db
  ->select("users WHERE username = ?")
  ->bind("mychi")
  ->fetchAssoc();

And yet again another syntax🧐 As said above, Leaf Db is highly customizable, and allows you to write queries in a way that suits you. This statement above binds mychi to the username.

db()
  ->select("users WHERE username = ? AND password = ?")
  ->bind("mychi", "password")
  ->fetchAssoc();

$db
  ->select("users WHERE username = ? AND password = ?")
  ->bind("mychi", "password")
  ->fetchAssoc();

You can just pass multiple parameters into bind, as many as satisfy your query. If you feel more comfortable with arrays, you can use arrays.

db()
  ->select("users WHERE username = ? AND password = ?")
  ->bind(["mychi", "password"])
  ->fetchAssoc();

$db
  ->select("users WHERE username = ? AND password = ?")
  ->bind(["mychi", "password"])
  ->fetchAssoc();

orderBy

orderBy allows you to arrange the query results according to a row, in ascending (asc) or descending (desc) order.

// if second param is not provided, desc is used by default
$items = db()->select("items")->orderBy("created_at")->all();

... orderBy("id", "desc")->all();

// if second param is not provided, desc is used by default
$items = $db->select("items")->orderBy("created_at")->all();

... orderBy("id", "desc")->all();

limit

When retrieving data from your database for use in applications, you might want to show only a specific number of values.

$itemsPerPage = 15;
$items = db()->select("items")->limit($itemsPerPage)->fetchAll();

// you can use limit and orderBy together
$items = db()
  ->select("items")
  ->orderBy("id", "desc")
  ->limit($itemsPerPage)
  ->fetchAll();

$itemsPerPage = 15;
$items = $db->select("items")->limit($itemsPerPage)->fetchAll();

// you can use limit and orderBy together
$items = $db
  ->select("items")
  ->orderBy("id", "desc")
  ->limit($itemsPerPage)
  ->fetchAll();

error handling

Errors come up all the time, user errors, that is. What happens when validation fails, or if someone has already registered a username. Leaf Db provides a simple way to track these errors.

$res = db()
  ->insert("users")
  ->params("username", "mychi")
  ->unique("username")
  ->execute();

if ($res === false) {
  response()->exit(db()->errors());
}

$res = $db
  ->insert("users")
  ->params("username", "mychi")
  ->unique("username")
  ->execute();

if ($res === false) {
  $app->response->exit(db()->errors());
}

Using db()->errors() returns an array holding any errors which caused the query to fail. eg:

[
  "email" => "email already exists",
  "username" => "username can only contain characters 0-9, A-z and _"
]

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Building Queries #

create #

drop #

select #

where #

Comparators #

orWhere #

find #

Table operations #

table #

search #

insert #

params #

unique #

update #

delete #

Extras #

hidden #

add #

bind #

orderBy #

limit #

error handling #