# Db


Access a database.

The most important function of this module is to clean a database before each test.
This module also provides actions to perform checks in a database, e.g. [seeInDatabase()](http://codeception.com/docs/modules/Db#seeInDatabase)

In order to have your database populated with data you need a raw SQL dump.
Simply put the dump in the `tests/_data` directory (by default) and specify the path in the config.
The next time after the database is cleared, all your data will be restored from the dump.
Don't forget to include `CREATE TABLE` statements in the dump.

Supported and tested databases are:

* MySQL
* SQLite (i.e. just one file)
* PostgreSQL

Also available:

* MS SQL
* Oracle

Connection is done by database Drivers, which are stored in the `Codeception\Lib\Driver` namespace.
[Check out the drivers](https://github.com/Codeception/Codeception/tree/2.3/src/Codeception/Lib/Driver)
if you run into problems loading dumps and cleaning databases.

## Config

* dsn *required* - PDO DSN
* user *required* - username to access database
* password *required* - password
* dump - path to database dump
* populate: false - whether the the dump should be loaded before the test suite is started
* cleanup: false - whether the dump should be reloaded before each test
* reconnect: false - whether the module should reconnect to the database before each test

## Example

    modules:
       enabled:
          - Db:
             dsn: 'mysql:host=localhost;dbname=testdb'
             user: 'root'
             password: ''
             dump: 'tests/_data/dump.sql'
             populate: true
             cleanup: true
             reconnect: true

## SQL data dump

There are two ways of loading the dump into your database:

### Populator

The recommended approach is to configure a `populator`, an external command to load a dump. Command parameters like host, username, password, database
can be obtained from the config and inserted into placeholders:

For MySQL:

```yaml
modules:
   enabled:
      - Db:
         dsn: 'mysql:host=localhost;dbname=testdb'
         user: 'root'
         password: ''
         dump: 'tests/_data/dump.sql'
         populate: true # run populator before all tests
         cleanup: true # run populator before each test
         populator: 'mysql -u $user -h $host $dbname < $dump'
```

For PostgreSQL (using pg_restore)

```
modules:
   enabled:
      - Db:
         dsn: 'pgsql:host=localhost;dbname=testdb'
         user: 'root'
         password: ''
         dump: 'tests/_data/db_backup.dump'
         populate: true # run populator before all tests
         cleanup: true # run populator before each test
         populator: 'pg_restore -u $user -h $host -D $dbname < $dump'
```

 Variable names are being taken from config and DSN which has a `keyword=value` format, so you should expect to have a variable named as the
 keyword with the full value inside it.

 PDO dsn elements for the supported drivers:
 * MySQL: [PDO_MYSQL DSN](https://secure.php.net/manual/en/ref.pdo-mysql.connection.php)
 * SQLite: [PDO_SQLITE DSN](https://secure.php.net/manual/en/ref.pdo-sqlite.connection.php)
 * PostgreSQL: [PDO_PGSQL DSN](https://secure.php.net/manual/en/ref.pdo-pgsql.connection.php)
 * MSSQL: [PDO_SQLSRV DSN](https://secure.php.net/manual/en/ref.pdo-sqlsrv.connection.php)
 * Oracle: [PDO_OCI DSN](https://secure.php.net/manual/en/ref.pdo-oci.connection.php)

### Dump

Db module by itself can load SQL dump without external tools by using current database connection.
This approach is system-independent, however, it is slower than using a populator and may have parsing issues (see below).

Provide a path to SQL file in `dump` config option:

```yaml
modules:
   enabled:
      - Db:
         dsn: 'mysql:host=localhost;dbname=testdb'
         user: 'root'
         password: ''
         populate: true # load dump before all tests
         cleanup: true # load dump for each test
         dump: 'tests/_data/dump.sql'
```

 To parse SQL Db file, it should follow this specification:
 * Comments are permitted.
 * The `dump.sql` may contain multiline statements.
 * The delimiter, a semi-colon in this case, must be on the same line as the last statement:

```sql
-- Add a few contacts to the table.
REPLACE INTO `Contacts` (`created`, `modified`, `status`, `contact`, `first`, `last`) VALUES
(NOW(), NOW(), 1, 'Bob Ross', 'Bob', 'Ross'),
(NOW(), NOW(), 1, 'Fred Flintstone', 'Fred', 'Flintstone');

-- Remove existing orders for testing.
DELETE FROM `Order`;
```
## Query generation

`seeInDatabase`, `dontSeeInDatabase`, `seeNumRecords`, `grabFromDatabase` and `grabNumRecords` methods
accept arrays as criteria. WHERE condition is generated using item key as a field name and
item value as a field value.

Example:
```php
<?php
$I->seeInDatabase('users', array('name' => 'Davert', 'email' => 'davert@mail.com'));

```
Will generate:

```sql
SELECT COUNT(*) FROM `users` WHERE `name` = 'Davert' AND `email` = 'davert@mail.com'
```
Since version 2.1.9 it's possible to use LIKE in a condition, as shown here:

```php
<?php
$I->seeInDatabase('users', array('name' => 'Davert', 'email like' => 'davert%'));

```
Will generate:

```sql
SELECT COUNT(*) FROM `users` WHERE `name` = 'Davert' AND `email` LIKE 'davert%'
```
## Public Properties
* dbh - contains the PDO connection
* driver - contains the Connection Driver



## Actions

### dontSeeInDatabase
 
Effect is opposite to ->seeInDatabase

Asserts that there is no record with the given column values in a database.
Provide table name and column values.

``` php
<?php
$I->dontSeeInDatabase('users', array('name' => 'Davert', 'email' => 'davert@mail.com'));
```
Fails if such user was found.

 * `param string` $table
 * `param array` $criteria


### grabFromDatabase
 
Fetches a single column value from a database.
Provide table name, desired column and criteria.

``` php
<?php
$mail = $I->grabFromDatabase('users', 'email', array('name' => 'Davert'));
```

 * `param string` $table
 * `param string` $column
 * `param array` $criteria



### grabNumRecords
 
Returns the number of rows in a database

 * `param string` $table    Table name
 * `param array`  $criteria Search criteria [Optional]

 * `return` int


### haveInDatabase
 
Inserts an SQL record into a database. This record will be erased after the test.

```php
<?php
$I->haveInDatabase('users', array('name' => 'miles', 'email' => 'miles@davis.com'));
?>
```

 * `param string` $table
 * `param array` $data

 * `return integer` $id


### isPopulated
__not documented__


### seeInDatabase
 
Asserts that a row with the given column values exists.
Provide table name and column values.

``` php
<?php
$I->seeInDatabase('users', array('name' => 'Davert', 'email' => 'davert@mail.com'));
```
Fails if no such user found.

 * `param string` $table
 * `param array` $criteria


### seeNumRecords
 
Asserts that the given number of records were found in the database.

```php
<?php
$I->seeNumRecords(1, 'users', ['name' => 'davert'])
?>
```

 * `param int` $expectedNumber Expected number
 * `param string` $table Table name
 * `param array` $criteria Search criteria [Optional]

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