如何在 "json_array" 类型的列上使用 Doctrine 在 Symfony 3 中添加复合索引？

Question

我有一个 table，我想添加这样的索引：

 @Index(columns={"child_id", "abilities"}),
 @Index(columns={"parent_id", "abilities"}),

...

 * @ORM\Column(type="json_array", length=256)
 */
protected $abilities;

但是，即使在迁移中添加了适当的限制之后：

$this->addSql('CREATE INDEX IDX_1088BF61DD62C21BB8388DA4 ON xxx (child_id, abilities(512))');
$this->addSql('CREATE INDEX IDX_1088BF61727ACA70B8388DA4 ON xxx (parent_id, abilities(512))');

当运行测试重新创建数据库时会出现这样的错误：

An exception occurred while executing '

CREATE TABLE xxx (
    id INT AUTO_INCREMENT NOT NULL, 
    parent_id INT DEFAULT NULL, 
    child_id INT DEFAULT NULL, 
    type VARCHAR(125) NOT NULL, 
    abilities LONGTEXT NOT NULL COMMENT '(DC2Type:json_array)', 
    created_at DATETIME NOT NULL, 
    modified_at DATETIME NOT NULL, 
    INDEX IDX_1088BF61727ACA70 (parent_id), 
    INDEX IDX_1088BF61DD62C21B (child_id), 
    INDEX IDX_1088BF61DD62C21B8CDE5729 (child_id, type), 
    INDEX IDX_1088BF61727ACA708CDE5729 (parent_id, type), 
    INDEX IDX_1088BF618CDE5729 (type), 
    INDEX IDX_1088BF61DD62C21BB8388DA4 (child_id, abilities), 
    INDEX IDX_1088BF61727ACA7 0B8388DA4 (parent_id, abilities), 
    INDEX IDX_1088BF61B8388DA4 (abilities), 
    UNIQUE INDEX UNIQ_1088BF61727ACA70DD62C21B (parent_id, child_id), 
    PRIMARY KEY(id)
) DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE = InnoDB

':

SQLSTATE[42000]: Syntax error or access violation: 1170 BLOB/TEXT column 'abilities' used in key specification without a key length

我需要做什么才能在这些列上成功创建索引？

Answer 1

索引长字符串有限制。

由于所讨论的字符串包含 "json"，因此对该列进行常规索引是没有用的。

解决方案：去掉这 3 个索引：

INDEX IDX_1088BF61DD62C21BB8388DA4 (child_id, abilities), 
INDEX IDX_1088BF61727ACA7 0B8388DA4 (parent_id, abilities), 
INDEX IDX_1088BF61B8388DA4 (abilities),

如何在 "json_array" 类型的列上使用 Doctrine 在 Symfony 3 中添加复合索引？

How do I add compound index in Symfony 3 using Doctrine on column of type "json_array"?

mysql

indexing

doctrine

symfony

php-7.1