francerz/sql-builder

SQL Builder


License
MIT

Documentation

SQL Builder

Packagist Build Status

A query builder that allows optimal performance object based query construction.

Table of contents

Installation

This package can be installed with composer using following command.

composer require francerz/sql-builder

Basic common usage syntax

class Group {
    public $group_id;
    public $subject;
    public $teacher;
}

Select query

// SELECT group_id, subject, teacher FROM groups
$query = Query::selectFrom('groups', ['group_id', 'subject', 'teacher']);

$db = DatabaseManager::connect('school');
$result = $db->executeSelect($query);
$groups = $result->toArray(Group::class);

Insert query

$group = new Group();
$group->subject = 'Database fundamentals';
$group->teacher = 'francerz';

// INSERT INTO groups (subject, teacher) VALUES ('Database fundamentals', 'francerz')
$query = Query::insertInto('groups', $group, ['subject', 'teacher']);

$db = DatabaseManager::connect('school');
$result = $db->executeInsert($query);
$group->group_id = $result->getInsertedId();

Update query

$group = new Group();
$group->group_id = 10;
$group->subject = 'Introduction to databases';

// UPDATE groups SET subject = 'Introduction to databases' WHERE group_id = 10
$query = Query::update('groups', $group, ['group_id'], ['subject']);

$db = DatabaseManager::connect('school');
$result = $db->executeUpdate($query);

Delete query

// DELETE FROM groups WHERE group_id = 10
$query = Query::deleteFrom('groups', ['group_id' => 10]);

$db = DatabaseManager::connect('school');
$result = $db->executeDelete($query);

Connect to database

Using an URI string

$db = DatabaseManager::connect('driver://user:password@host:port/database');

Using $_ENV global variable

$_ENV['DATABASE_SCHOOL_DRIVER'] = 'driver';
$_ENV['DATABASE_SCHOOL_HOST'] = 'host';
$_ENV['DATABASE_SCHOOL_PORT'] = 'port';
$_ENV['DATABASE_SCHOOL_USER'] = 'user';
$_ENV['DATABASE_SCHOOL_PSWD'] = 'password';
$_ENV['DATABASE_SCHOOL_NAME'] = 'database';

$db = DatabaseManager::connect('school');

Build SELECT with WHERE or HAVING clause

Bellow are examples of using WHERE clause which aplies to SELECT, UPDATE and DELETE queries.

SELECT * FROM groups WHERE group_id = 10
// Explicit syntax
$query = Query::selectFrom('groups')->where()->equals('group_id', 10);

// Implicit syntax
$query = Query::selectFrom('groups')->where('group_id', 10);
SELECT * FROM groups WHERE group_id IN (10, 20, 30)
// Explicit syntax
$query = Query::selectFrom('groups')->where()->in('group_id', [10, 20, 30]);

// Implicit syntax
$query = Query::selectFrom('groups')->where('group_id', [10, 20, 30]);
SELECT * FROM groups WHERE teacher IS NULL
// Explicit syntax
$query = Query::selectFrom('groups')->where()->null('teacher');

// Implicit compact syntax
$query = Query::selectFrom('groups')->where('teacher', 'NULL');
SELECT * FROM groups WHERE group_id <= 10 AND subject LIKE '%database%'
// Explicit syntax
$query = Query::selectFrom('groups');
$query->where()->lessEquals('group_id', 10)->andLike('subject', '%database%');

// Implicit compact syntax
$query = Query::selectFrom('groups');
$query->where('group_id', '<=', 10)->andLike('subject', '%database%');
SELECT * FROM groups WHERE (group_id = 10 OR group_id BETWEEN 20 AND 30)
$query = Query::selectFrom('groups');

// Using an anonymous function to emulate parenthesis
$query->where(function(ConditionList $subwhere) {
    $subwhere
        ->equals('group_id', 10)
        ->orBetween('group_id', 20, 30);
});

Parenthesis anonymous function only works in the following syntax.

  • $query->where(function)
  • $query->where()->not(function)
  • $query->where()->and(function)
  • $query->where()->or(function)
  • $query->where()->andNot(function)
  • $query->where()->orNot(function)

List of operators

Operator Regular (AND) AND OR
= equals($op1, $op2) andEquals($op1, $op2) orEquals($op1, $op2)
<> or != notEquals($op1, $op2) andNotEquals($op1, $op2) orNotEquals($op1, $op2)
< lessThan($op1, $op2) andLessThan($op1, $op2) orLessthan($op1, $op2)
<= lessEquals($op1, $op2) andLessEquals($op1, $op2) orLessEquals($op1, $op2)
> greaterThan($op1, $op2) andGreaterThan($op1, $op2) orGreaterThan($op1, $op2)
>= greaterEquals($op1, $op2) andGreaterEquals($op1, $op2) orGreaterEquals($op1, $op2)
LIKE like($op1, $op2) andLike($op1, $op2) orLike($op1, $op2)
NOT LIKE notLike($op1, $op2) andNotLike($op1, $op2) orNotLike($op1, $op2)
IS NULL null($op) andNull($op) orNull($op)
IS NOT NULL notNull($op) andNotNull($op) orNotNull($op)
BETWEEN between($op, $min, $max) andBetween($op, $min, $max) orBetween($op, $min, $max)
NOT BETWEEN notBetween($op, $min, $max) andNotBetween($op, $min, $max) orNotBetween($op, $min, $max)
IN in($op, $array) andIn($op, $array) orIn($op, $array)
NOT IN notIn($op, $array) andNotIn($op, $array) orNotIn($op, $array)

About ConditionList class

The examples of condition list, functions and operators applies in the same way to WHERE, HAVING and ON syntax.


Building SELECT with JOIN

SELECT * FROM groups INNER JOIN teachers ON groups.teacher_id = teachers.teacher_id
$query = Query::selectFrom('groups');
$query->innerJoin('teachers')->on('groups.teacher_id', 'teachers.teacher_id');

Using table aliases to reduce naming lenght.

SELECT * FROM groups AS g INNER JOIN teachers AS t ON g.teacher_id = t.teacher_id
// Alias array syntax
$query = Query::selectFrom(['g' => 'groups']);
$query->innerJoin(['t' => 'teachers'])->on('g.teacher_id', 't.teacher_id');

// Alias "AS" string syntax
$query = Query::selectFrom('groups AS g');
$query->innerJoin('teachers AS t')->on('g.teacher_id', 't.teacher_id');

Multiple database (same host) select with join.

SELECT * FROM school.groups AS g INNER JOIN hr.employees AS e ON g.teacher_id = e.employee_id
$query = Query::selectFrom('school.groups AS g');
$query->innerJoin('hr.employees AS e')->on('g.teacher_id','e.employee_id');

Selecting fields from joined tables

SELECT g.group_id, t.given_name, t.family_name
FROM groups AS g
INNER JOIN teachers AS t ON g.teacher_id = t.teacher_id
$query = Query::selectFrom('groups AS g', ['group_id']);
$query->innerJoin('teachers AS t', ['given_name', 'family_name'])
    ->on('g.teacher_id', 't.teacher_id');

Renaming fields from joined tables

SELECT g.group_id, CONCAT(t.given_name, ' ', t.family_name) AS teacher_name
FROM groups AS g
INNER JOIN teachers AS t ON g.teacher_id = t.teacher_id
$query = Query::selectFrom('groups AS g', ['group_id']);
$query->innerJoin('teachers AS t', ['teacher_name' => "CONCAT(t.given_name, ' ', t.family_name)"])
    ->on('g.teacher_id', 't.teacher_id');

Selecting columns into an external function (cleaner code)

SELECT g.group_id, CONCAT(t.given_name, ' ', t.family_name) AS teacher_name
FROM groups AS g
INNER JOIN teachers AS t ON g.teacher_id = t.teacher_id
$query = Query::selectFrom('groups AS g');
$query->innerJoin('teachers AS t')->on('g.teacher_id', 't.teacher_id');
$query->columns([
    'g.group_id',
    'teacher_name' => "CONCAT(t.given_name, ' ', t.family_name)"
]);

Join tables and subqueries

-- Gets all groups of active teachers
SELECT g.group_id, CONCAT(t.given_name, ' ', t.family_name) AS teacher_name
FROM groups AS g
INNER JOIN (SELECT * FROM teachers WHERE active = 1) AS t
ON g.teacher_id = t.teacher_id
// Creating subquery object
$subquery = Query::selectFrom('teachers');
$subquery->where('active', 1);

$query = Query::selectFrom('groups AS g');
$query->innerJoin(['t' => $subquery])->on('g.teacher_id', 't.teacher_id');
$query->columns([
    'g.group_id',
    'teacher_name' => "CONCAT(t.given_name, ' ', t.family_name)"
]);

SUPPORTED JOIN TYPES

Query Builder supports many types of JOIN:

  • innerJoin(table, columns = [])
  • crossJoin(table, columns = [])
  • leftJoin(table, columns = [])
  • rightJoin(table, columns = [])

NOTE:

Join Syntax is available to SELECT, UPDATE and DELETE sql syntax, however, not all database engines might support it.

SELECT nesting

Sometimes database table joining might not be enought for all the data requirements. Is quite often that for each row in a result of a query, another filtered result query must be executed.

This scenario produces excesive complex code to nest each result by each row. Also impacts performance by increasing the loops and database access roundtrips. For this reason there's a syntax that creates the most lightweight and efficient way to query nested data, preventing access overhead and reducing processing time.

// Students query
$studentsQuery = Query::selectFrom(
    'students',
    ['student_id', 'group_id', 'first_name', 'last_name']
);

// Groups query
$groupsQuery = Query::selectFrom(
    'groups',
    ['group_id', 'subject', 'teacher']
);

// Nesting students by each group
$groupsQuery->nest(['Students' => $studentsQuery], function (NestedSelect $nest, RowProxy $row) {
    $nest->getSelect()->where('s.group_id', $row->group_id);
});

$db = DatabaseManager::connect('school');
$result = $db->executeSelect($groupsQuery);
$groups = $result->toArray();

Result might be like this:

[
    {
        "group_id": 1,
        "subject": "Programing fundamentals",
        "teacher": "Rosemary",
        "Students": [
            {
                "student_id": 325,
                "first_name": "Charlie",
                "last_name": "Ortega"
            },
            {
                "student_id": 743,
                "first_name": "Beth",
                "last_name": "Wilson"
            }
        ]
    },
    {
        "group_id": 2,
        "subject" : "Object Oriented Programming",
        "teacher": "Steve",
        "Students": [
            {
                "student_id": 536,
                "first_name": "Dylan",
                "last_name": "Morrison"
            }
        ]
    }
]

Executing Stored Procedures

// Connecting to database 'school'.
$db = DatabaseManager::connect('school');

// Calls stored procedure with two argments.
/** @var SelectResult[] */
$results = $db->call('procedure_name', 'arg1', 'arg2');

// Shows how many results obtained from procedure.
echo count($results) . ' results.' . PHP_EOL;

// Iterating procedure result sets.
foreach ($results as $i => $selectResult) {
    echo "Fetched " . $selectResult->getNumRows() . PHP_EOL;
}