如何查找所有具有引用特定表的外键的表。列和那些外键的值?

我有一个表，它的主键在其他几个表中作为外键引用。例如:

  CREATE TABLE `X` (
    `X_id` int NOT NULL auto_increment,
    `name` varchar(255) NOT NULL,
    PRIMARY KEY  (`X_id`)
  )
  CREATE TABLE `Y` (
    `Y_id` int(11) NOT NULL auto_increment,
    `name` varchar(255) NOT NULL,
    `X_id` int DEFAULT NULL,
    PRIMARY KEY  (`Y_id`),
    CONSTRAINT `Y_X` FOREIGN KEY (`X_id`) REFERENCES `X` (`X_id`)
  )
  CREATE TABLE `Z` (
    `Z_id` int(11) NOT NULL auto_increment,
    `name` varchar(255) NOT NULL,
    `X_id` int DEFAULT NULL,
    PRIMARY KEY  (`Z_id`),
    CONSTRAINT `Z_X` FOREIGN KEY (`X_id`) REFERENCES `X` (`X_id`)
  )

现在，我不知道数据库中有多少表包含X的外键，如表Y和z。是否有一个SQL查询，我可以使用返回:

具有X外键的表列表 AND这些表中哪些外键中有值

当前回答

列出一个db中的所有外键，包括描述

    SELECT  
    i1.CONSTRAINT_NAME, i1.TABLE_NAME,i1.COLUMN_NAME,
    i1.REFERENCED_TABLE_SCHEMA,i1.REFERENCED_TABLE_NAME, i1.REFERENCED_COLUMN_NAME,
    i2.UPDATE_RULE, i2.DELETE_RULE 
    FROM   
    information_schema.KEY_COLUMN_USAGE AS i1  
    INNER JOIN 
    information_schema.REFERENTIAL_CONSTRAINTS AS i2 
    ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME 
    WHERE i1.REFERENCED_TABLE_NAME IS NOT NULL  
    AND  i1.TABLE_SCHEMA  ='db_name';

限制到表中的特定列

AND i1.table_name = 'target_tb_name' AND i1.column_name = 'target_col_name'

2016-09-15 08:40:38

其他回答

简单的: 1. 打开phpMyAdmin 2. 在左侧单击数据库名称 3.在右上角找到“设计者”标签

所有的约束都将显示在那里。

2017-12-01 07:15:04

MySQL 5.5参考手册:InnoDB和外键约束

SELECT
  ke.REFERENCED_TABLE_SCHEMA parentSchema,
  ke.referenced_table_name parentTable,
  ke.REFERENCED_COLUMN_NAME parentColumnName,
  ke.TABLE_SCHEMA ChildSchema,
  ke.table_name childTable,
  ke.COLUMN_NAME ChildColumnName
FROM
  information_schema.KEY_COLUMN_USAGE ke
WHERE
  ke.referenced_table_name IS NOT NULL
  AND ke.REFERENCED_COLUMN_NAME = 'ci_id' ## Find Foreign Keys linked to this Primary Key
ORDER BY
  ke.referenced_table_name;

2010-07-22 17:23:50

这个解决方案不仅会显示所有的关系，还会显示约束的名称，这在某些情况下是必需的(例如drop constraint):

SELECT
    CONCAT(table_name, '.', column_name) AS 'foreign key',
    CONCAT(referenced_table_name, '.', referenced_column_name) AS 'references',
    constraint_name AS 'constraint name'
FROM
    information_schema.key_column_usage
WHERE
    referenced_table_name IS NOT NULL;

如果您想检查特定数据库中的表，请添加以下内容:

AND table_schema = 'database_name';

2013-09-16 10:35:10

列出一个db中的所有外键，包括描述

    SELECT  
    i1.CONSTRAINT_NAME, i1.TABLE_NAME,i1.COLUMN_NAME,
    i1.REFERENCED_TABLE_SCHEMA,i1.REFERENCED_TABLE_NAME, i1.REFERENCED_COLUMN_NAME,
    i2.UPDATE_RULE, i2.DELETE_RULE 
    FROM   
    information_schema.KEY_COLUMN_USAGE AS i1  
    INNER JOIN 
    information_schema.REFERENTIAL_CONSTRAINTS AS i2 
    ON i1.CONSTRAINT_NAME = i2.CONSTRAINT_NAME 
    WHERE i1.REFERENCED_TABLE_NAME IS NOT NULL  
    AND  i1.TABLE_SCHEMA  ='db_name';

限制到表中的特定列

AND i1.table_name = 'target_tb_name' AND i1.column_name = 'target_col_name'

2016-09-15 08:40:38

给你:

SELECT *
FROM
  information_schema.KEY_COLUMN_USAGE
WHERE
  REFERENCED_TABLE_NAME = 'X'
  AND REFERENCED_COLUMN_NAME = 'X_id';

如果你有多个具有相似表/列名的数据库，你可能也希望将查询限制在一个特定的数据库:

SELECT *
FROM
  information_schema.KEY_COLUMN_USAGE
WHERE
  REFERENCED_TABLE_NAME = 'X'
  AND REFERENCED_COLUMN_NAME = 'X_id'
  AND TABLE_SCHEMA = 'your_database_name';

2009-07-15 19:27:30

如何查找所有具有引用特定表的外键的表。列和那些外键的值?

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