查询语言.aggregate

数据库聚合查询功能。

引入相关类

• use Tests\Database\DatabaseTestCase as TestCase;

  记录数量 count

计算记录数量。

函数原型

public function findCount(string $field = '*', string $alias = 'row_count', bool $flag = false);

::: tip
可使用 findCount() 或者 count()->find() 来统计记录行。
:::

public function testBaseUse()
{
    $connect = $this->createDatabaseConnectMock();
    $sql = <<<'eot'
        [
            "SELECT COUNT(*) AS row_count FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            count()->
            findOne(true)
        )
    );
    $sql = <<<'eot'
        [
            "SELECT COUNT(`test`.`id`) AS row_count FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            count('id')->
            findOne(true),
            1
        )
    );
    $sql = <<<'eot'
        [
            "SELECT COUNT(`test`.`id`) AS count1 FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            count('id', 'count1')->
            findOne(true),
            2
        )
    );
    $sql = <<<'eot'
        [
            "SELECT COUNT(`test`.`id`*50) AS count1 FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            count('{[id]*50}', 'count1')->
            findOne(true),
            3
        )
    );
}

平均值 avg

计算平均值。

public function testAvg()
{
    $connect = $this->createDatabaseConnectMock();
    $sql = <<<'eot'
        [
            "SELECT AVG(`test`.`id`) AS avg_value FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            avg('id')->
            findOne(true)
        )
    );
}

最大值 max

计算最大值。

public function testMax()
{
    $connect = $this->createDatabaseConnectMock();
    $sql = <<<'eot'
        [
            "SELECT MAX(`test`.`num`) AS max_value FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            max('num')->
            findOne(true)
        )
    );
}

最小值 min

计算最小值。

public function testMin()
{
    $connect = $this->createDatabaseConnectMock();
    $sql = <<<'eot'
        [
            "SELECT MIN(`test`.`num`) AS min_value FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            min('num')->
            findOne(true)
        )
    );
}

合计 sum

计算合计。

public function testSum()
{
    $connect = $this->createDatabaseConnectMock();
    $sql = <<<'eot'
        [
            "SELECT SUM(`test`.`num`) AS sum_value FROM `test` LIMIT 1",
            [],
            false,
            null,
            null,
            []
        ]
        eot;
    $this->assertSame(
        $sql,
        $this->varJson(
            $connect->table('test')->
            sum('num')->
            findOne(true)
        )
    );
}