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

我写了一个小bash onliner，你可以写一个脚本来得到一个友好的输出:

mysql_references_to:

mysql -uUSER -pPASS -A DB_NAME -se "USE information_schema; SELECT * FROM KEY_COLUMN_USAGE WHERE REFERENCED_TABLE_NAME = '$1' AND REFERENCED_COLUMN_NAME = 'id'\G" | sed 's/^[ \t]*//;s/[ \t]*$//' |egrep "\<TABLE_NAME|\<COLUMN_NAME" |sed 's/TABLE_NAME: /./g' |sed 's/COLUMN_NAME: //g' | paste -sd "," -| tr '.' '\n' |sed 's/,$//' |sed 's/,/./'

因此执行:mysql_references_to transaccion(其中transaccion是一个随机表名)给出如下输出:

carrito_transaccion.transaccion_id
comanda_detalle.transaccion_id
comanda_detalle_devolucion.transaccion_positiva_id
comanda_detalle_devolucion.transaccion_negativa_id
comanda_transaccion.transaccion_id
cuenta_operacion.transaccion_id
...

2015-03-11 10:23:53

其他回答

您可以在明智地命名为information_schema表中找到所有与模式相关的信息。

您可能需要检查REFERENTIAL_CONSTRAINTS和KEY_COLUMN_USAGE表。前者告诉你哪些表被其他人引用;后者会告诉你他们的领域是如何相关的。

2009-04-30 13:57:38

选择table_name, column_name 从information_schema。KEY_COLUMN_USAGE WHERE CONSTRAINT_SCHEMA LIKE 'your_database' 和TABLE_SCHEMA LIKE 'your_database' AND REFERENCED_TABLE_SCHEMA LIKE 'your_database' 和REFERENCED_TABLE_NAME LIKE 'your_table' AND REFERENCED_COLUMN_NAME LIKE 'your_column';

2021-04-01 20:59:35

06 2022

基于@Panayotis的回答，但结构更好。

这将从多个表中列出所有约束。我还包含了TABLE_SCHEMA以显示数据库名称。

SQL

SELECT
    TABLE_SCHEMA AS 'Database',
    TABLE_NAME AS t1,
    REFERENCED_TABLE_NAME AS 't2 (reference table)',
    COLUMN_NAME AS 't1 column',
    REFERENCED_COLUMN_NAME AS 't2 column (reference table)',
    CONSTRAINT_NAME AS 't1 (constrain name)'
FROM
    information_schema.key_column_usage
WHERE
    referenced_table_name IS NOT NULL

输出

+------------+------------+---------------------+---------------+----------------------------+------------------------+
| Database   | t1         | t2 (reference table) | t1 column     | t2 column (reference table) | t1 (constrain name)    |
+============+============+=====================+===============+============================+========================+
| foobar     | credential | userdetail          | userdetail_fk | id                         | credentialUserdetailFk |
+------------+------------+---------------------+---------------+----------------------------+------------------------+
| foobar     | loginlog   | userdetail          | userdetail_fk | id                         | loginlogUserdetailFk   |
+------------+------------+---------------------+---------------+----------------------------+------------------------+
+ client     | userdetail | client              | client_fk     | id                         | userdetailClientFk     |
+------------+------------+---------------------+---------------+----------------------------+------------------------+

2022-06-03 03:12:37

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

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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