Polecenie Pokaż ograniczenia w tabelach
Mam tabele, na których próbowałem ustawić relacje PK FK, ale chcę to zweryfikować. Jak mogę pokazać ograniczenia PK / FK? Widziałem tę stronę podręcznika, ale nie pokazuje przykładów i moje wyszukiwanie w google również było bezowocne. Moja baza danych to credentialing1
, a moje tabele ograniczające to practices
i cred_insurances
.
8 answers
Używam
SHOW CREATE TABLE mytable;
To pokazuje instrukcję SQL niezbędną do odebrania mytable
w obecnej formie. Możesz zobaczyć wszystkie kolumny i ich typy (jak DESC
), ale pokazuje również informacje o ograniczeniach (i typ tabeli, charset, itp.).
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2010-10-23 15:24:39
Po prostu zapytanie INFORMATION_SCHEMA:
USE INFORMATION_SCHEMA;
SELECT TABLE_NAME,
COLUMN_NAME,
CONSTRAINT_NAME,
REFERENCED_TABLE_NAME,
REFERENCED_COLUMN_NAME
FROM KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA = "<your_database_name>"
AND TABLE_NAME = "<your_table_name>"
AND REFERENCED_COLUMN_NAME IS NOT NULL;
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2017-08-21 09:43:34
Głównym problemem z potwierdzoną odpowiedzią jest to, że będziesz musiał przeanalizować wyjście, aby uzyskać informacje. Oto zapytanie pozwalające uzyskać je w bardziej użyteczny sposób:
SELECT cols.TABLE_NAME, cols.COLUMN_NAME, cols.ORDINAL_POSITION,
cols.COLUMN_DEFAULT, cols.IS_NULLABLE, cols.DATA_TYPE,
cols.CHARACTER_MAXIMUM_LENGTH, cols.CHARACTER_OCTET_LENGTH,
cols.NUMERIC_PRECISION, cols.NUMERIC_SCALE,
cols.COLUMN_TYPE, cols.COLUMN_KEY, cols.EXTRA,
cols.COLUMN_COMMENT, refs.REFERENCED_TABLE_NAME, refs.REFERENCED_COLUMN_NAME,
cRefs.UPDATE_RULE, cRefs.DELETE_RULE,
links.TABLE_NAME, links.COLUMN_NAME,
cLinks.UPDATE_RULE, cLinks.DELETE_RULE
FROM INFORMATION_SCHEMA.`COLUMNS` as cols
LEFT JOIN INFORMATION_SCHEMA.`KEY_COLUMN_USAGE` AS refs
ON refs.TABLE_SCHEMA=cols.TABLE_SCHEMA
AND refs.REFERENCED_TABLE_SCHEMA=cols.TABLE_SCHEMA
AND refs.TABLE_NAME=cols.TABLE_NAME
AND refs.COLUMN_NAME=cols.COLUMN_NAME
LEFT JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS cRefs
ON cRefs.CONSTRAINT_SCHEMA=cols.TABLE_SCHEMA
AND cRefs.CONSTRAINT_NAME=refs.CONSTRAINT_NAME
LEFT JOIN INFORMATION_SCHEMA.`KEY_COLUMN_USAGE` AS links
ON links.TABLE_SCHEMA=cols.TABLE_SCHEMA
AND links.REFERENCED_TABLE_SCHEMA=cols.TABLE_SCHEMA
AND links.REFERENCED_TABLE_NAME=cols.TABLE_NAME
AND links.REFERENCED_COLUMN_NAME=cols.COLUMN_NAME
LEFT JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS cLinks
ON cLinks.CONSTRAINT_SCHEMA=cols.TABLE_SCHEMA
AND cLinks.CONSTRAINT_NAME=links.CONSTRAINT_NAME
WHERE cols.TABLE_SCHEMA=DATABASE()
AND cols.TABLE_NAME="table"
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2016-04-07 11:52:05
Afaik aby złożyć wniosek do information_schema
potrzebujesz uprawnień. Jeśli potrzebujesz prostej listy kluczy, możesz użyć tego polecenia:
SHOW INDEXES IN <tablename>
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2016-02-17 06:58:49
Spróbuj wykonać:
SHOW TABLE STATUS FROM credentialing1;
Ograniczenia klucza obcego są wymienione w kolumnie Comment wyjścia.
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2010-10-23 13:49:30
Możesz użyć tego:
select
table_name,column_name,referenced_table_name,referenced_column_name
from
information_schema.key_column_usage
where
referenced_table_name is not null
and table_schema = 'my_database'
and table_name = 'my_table'
Lub dla lepszego sformatowania wyjścia użyj tego:
select
concat(table_name, '.', column_name) as 'foreign key',
concat(referenced_table_name, '.', referenced_column_name) as 'references'
from
information_schema.key_column_usage
where
referenced_table_name is not null
and table_schema = 'my_database'
and table_name = 'my_table'
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2013-03-17 21:01:23
Analogicznie do @ Resh32 , ale bez potrzeby stosowania USE
instrukcji:
SELECT TABLE_NAME,
COLUMN_NAME,
CONSTRAINT_NAME,
REFERENCED_TABLE_NAME,
REFERENCED_COLUMN_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA = "database_name"
AND TABLE_NAME = "table_name"
AND REFERENCED_COLUMN_NAME IS NOT NULL;
Przydatne, np. przy użyciu ORM.
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2017-08-21 09:11:38
Istnieje również narzędzie, które Oracle stworzył o nazwie mysqlshow
Jeśli uruchomisz go z opcją --k keys $table_name
wyświetli klucze.
SYNOPSIS
mysqlshow [options] [db_name [tbl_name [col_name]]]
.......
.......
.......
· --keys, -k
Show table indexes.
Przykład:
╰─➤ mysqlshow -h 127.0.0.1 -u root -p --keys database tokens
Database: database Table: tokens
+-----------------+------------------+--------------------+------+-----+---------+----------------+---------------------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+-----------------+------------------+--------------------+------+-----+---------+----------------+---------------------------------+---------+
| id | int(10) unsigned | | NO | PRI | | auto_increment | select,insert,update,references | |
| token | text | utf8mb4_unicode_ci | NO | | | | select,insert,update,references | |
| user_id | int(10) unsigned | | NO | MUL | | | select,insert,update,references | |
| expires_in | datetime | | YES | | | | select,insert,update,references | |
| created_at | timestamp | | YES | | | | select,insert,update,references | |
| updated_at | timestamp | | YES | | | | select,insert,update,references | |
+-----------------+------------------+--------------------+------+-----+---------+----------------+---------------------------------+---------+
+--------+------------+--------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+--------+------------+--------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| tokens | 0 | PRIMARY | 1 | id | A | 2 | | | | BTREE | | |
| tokens | 1 | tokens_user_id_foreign | 1 | user_id | A | 2 | | | | BTREE | | |
+--------+------------+--------------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2017-04-25 07:17:00