WHERE语法-Medoo使用指南

摘要  本篇将介绍Medoo的WHERE语法。Medoo的一些方法要求传递$where参数，像SQL的WHERE子句那样用于筛选查询记录。WHERE子句很强大，但有很多复杂的语法，逻辑相关性，以及有关SQL注入的潜在安全问题。但Medoo提供了强大和极端易用的方式来构造WHERE子句和预防SQL注入。

Where  Medoo  MySQL  Medoo手册  Medoo翻译

上一篇《Medoo入门：安装和配置-Medoo使用指南》中介绍了Medoo的安装、配置和基本使用。本篇将介绍Medoo的WHERE语法。Medoo的一些方法要求传递$where参数，像SQL的WHERE子句那样用于筛选查询记录。WHERE子句很强大，但有很多复杂的语法，逻辑相关性，以及有关SQL注入的潜在安全问题。但Medoo提供了强大和极端易用的方式来构造WHERE子句和预防SQL注入。

基本条件

基本条件足够简单易懂。您可以使用其他符号来获得用于数字的高级过滤器。

$database ->select( "account" ,  "user_name" , [
    "email"  =>  "[email protected]"
]);
// WHERE email = '[email protected]'

$database ->select( "account" ,  "user_name" , [
    "user_id"  => 200
]);
// WHERE user_id = 200

$database ->select( "account" ,  "user_name" , [
    "user_id[>]"  => 200
]);
// WHERE user_id > 200

$database ->select( "account" ,  "user_name" , [
    "user_id[>=]"  => 200
]);
// WHERE user_id >= 200

$database ->select( "account" ,  "user_name" , [
    "user_id[!]"  => 200
]);
// WHERE user_id != 200

$database ->select( "account" ,  "user_name" , [
    "age[<>]"  => [200, 500]
]);
// WHERE age BETWEEN 200 AND 500

// 你不仅可以使用单一的字符串或数字值，也可以使用数组
$database ->select( "account" ,  "user_name" , [
    "OR"  => [
        "user_id"  => [2, 123, 234, 54],
        "email"  => [ "[email protected]" ,  "[email protected]" ,  "[email protected]" ]
    ]
]);
// WHERE
// user_id IN (2,123,234,54) OR
// email IN ('[email protected]','[email protected]','[email protected]')

// 否定条件 (自Medoo 0.9起支持)
$database ->select( "account" ,  "user_name" , [
    "AND"  => [
        "user_name[!]"  =>  "foo" ,
        "user_id[!]"  => 1024,
        "email[!]"  => [ "[email protected]" ,  "[email protected]" ,  "[email protected]" ],
        "city[!]"  => null
    ]
]);
// WHERE
// `user_name` != 'foo' AND
// `user_id` != 1024 AND
// `email` NOT IN ('[email protected]','[email protected]','[email protected]') AND
// `city` IS NOT NULL

// 可以从 select()或get()方法的结果取得
$database ->select( "account" ,  "user_name" , [
    "user_id"  =>  $database ->select( "post" ,  "user_id" , [ "comments[>]"  => 40])
]);
// WHERE user_id IN (2, 51, 321, 3431)

相对条件 

相对条件可以描述数据和数据之间的复杂关系。您可以使用“and”和“or”来构建复杂的相对条件查询。

// [基本的相对条件]
$database ->select( "account" ,  "user_name" , [
    "AND"  => [
        "user_id[>]"  => 200,
        "age[<>]"  => [18, 25],
        "gender"  =>  "female"
    ]
]);
// WHERE user_id > 200 AND age BETWEEN 18 AND 25 AND gender = 'female'

$database ->select( "account" ,  "user_name" , [
    "OR"  => [
        "user_id[>]"  => 200,
        "age[<>]"  => [18, 25],
        "gender"  =>  "female"
    ]
]);
// WHERE user_id > 200 OR age BETWEEN 18 AND 25 OR gender = 'female'

// [复合的相对条件]
$database ->has( "account" , [
    "AND"  => [
        "OR"  => [
            "user_name"  =>  "foo" ,
            "email"  =>  "[email protected]"
        ],
        "password"  =>  "12345"
    ]
]);
// WHERE (user_name = 'foo' OR email = '[email protected]') AND password = '12345'

全文搜索

通过目标关键词搜索记录。

// [MATCH]
$database ->select( "post_table" ,  "post_id" , [
    "MATCH"  => [
        "columns"  => [ "content" ,  "title" ],
        "keyword"  =>  "foo"
    ]
]);
// WHERE MATCH (content, title) AGAINST ('foo')

// [LIKE]
// The default connector of LIKE is AND
$database ->select( "account" ,  "user_id" , [
    'LIKE'  => [
        'location'  =>  "foo" ,
        'nickname'  =>  "foo" ,
        'user_name'  =>  "foo" ,
        'description'  =>  "foo"
    ]
]);

$database ->select( "account" ,  "user_id" , [
    'LIKE'  => [
        'AND'  => [
            'location'  =>  "foo" ,
            'nickname'  =>  "foo" ,
            'user_name'  =>  "foo" ,
            'description'  =>  "foo"
        ]
    ]
]);
// WHERE (
//  location LIKE '%foo%' AND
//  nickname LIKE '%foo%' AND
//  user_name LIKE '%foo%' AND
//  description LIKE '%foo%'
// )

$database ->select( "account" ,  "user_id" , [
    'LIKE'  => [
        'OR'  => [
            'location'  =>  "foo" ,
            'nickname'  =>  "foo" ,
            'user_name'  =>  "foo" ,
            'description'  =>  "foo"
        ]
    ]
]);
// WHERE (
//  location LIKE '%foo%' OR
//  nickname LIKE '%foo%' OR
//  user_name LIKE '%foo%' OR
//  description LIKE '%foo%'
// )

附加条件

$database ->select( "account" ,  "user_id" , [
    "GROUP"  =>  "type" ,

    // "ORDER" => "age DESC"
    "ORDER"  =>  "age" ,

    // Must have to use it with ORDER together
    "HAVING"  => [
        "user_id[>]"  => 500
    ],

    // LIMIT => 20
    "LIMIT"  => [20, 100]
]);
//  SELECT user_id FROM account
//  GROUP BY type
//  ORDER BY age
//  HAVING user_id > 500
//  LIMIT 20,100

原文标题：WHERE语法-Medoo使用指南

原文链接：http://loiy.net/post/566.html