mysql delete primary index
DROP INDEX drops the index named index_name from the table tbl_name . This statement is mapped to an ALTER TABLE statement to drop the index. See Section 13.1.8, “ALTER TABLE Syntax”. To drop a primary key, the index name is always PRIMARY , which must b,DROP [ONLINE|OFFLINE] INDEX index_name ON tbl_name. DROP INDEX drops the index named index_name from the table tbl_name . This statement is mapped to an ALTER TABLE statement to drop the index. See Section 13.1.7, “ALTER TABLE Syntax”. To drop a primary k, Without an index, maintaining an autoincrement column becomes too expensive, that's why MySQL requires an autoincrement column to be a leftmost part of an index. You should remove the autoincrement property before dropping the key: ALTER TABLE user_c,If you're sure this is what you want to do (note Paul Tomblin's comment on your question), then from the ALTER TABLE docs: ALTER TABLE `tablename` DROP PRIMARY KEY;. DROP PRIMARY KEY drops the primary key. If there is no primary key, an error occu, You should remove auto_increment first and then drop the primary key.. so try this: ALTER TABLE `mytable` CHANGE ... you need remove the FK s before. On MySQL, do like this: ALTER TABLE `table_name` DROP FOREIGN KEY `id_name_fk`; ALTER TABLE `table_name`, create table fixit (user_2, user_1, type, timestamp, n, primary key( user_2, user_1, type) ); lock table fixit write, user_interactions u write, user_interactions write; insert into fixit select user_2, user_1, type, max(timestamp), count(*) n from user_, list all non-unique indexes SELECT table_name AS `Table`, index_name AS `Index`, GROUP_CONCAT(column_name ORDER BY seq_in_index) AS `Columns` FROM information_schema.statistics WHERE NON_UNIQUE = 1 AND table_schema = 'mydatabase' AND table_name =, Run this command in the mysql client: mysql> SHOW CREATE TABLE listings;. It will show you the DDL for the table, including the system-assigned name for the index.,mysql 建立索引刪除索引查看索引使用索引，能夠提高查詢的速度 1、建立索引1)ALTERTABLE 創建普通索引，UNIQUE索引或者PRIMARY KEY索引ALTER TABLE table_name ADD INDEX index_name(column_list) ALTER TABLE table_name ADD UNIQUE(column_list) ALTER TABLE table_name ADD PRIMARY ... ,The RazorSQL alter table tool includes a Drop Primary Key option for dropping a primary key from a MySQL database table. The drop primary key function generates the appropriate alter table drop primary key SQL command for dropping the key from the table.
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 mysql delete primary index 相關參考資料
MySQL :: MySQL 5.7 Reference Manual :: 13.1.25 DROP INDEX Syntax
DROP INDEX drops the index named index_name from the table tbl_name . This statement is mapped to an ALTER TABLE statement to drop the index. See Section 13.1.8, “ALTER TABLE Syntax”. To drop a prima... https://dev.mysql.com MySQL :: MySQL 5.5 Reference Manual :: 13.1.24 DROP INDEX Syntax
DROP [ONLINE|OFFLINE] INDEX index_name ON tbl_name. DROP INDEX drops the index named index_name from the table tbl_name . This statement is mapped to an ALTER TABLE statement to drop the index. See Se... https://dev.mysql.com sql - Remove Primary Key in MySQL - Stack Overflow
Without an index, maintaining an autoincrement column becomes too expensive, that's why MySQL requires an autoincrement column to be a leftmost part of an index. You should remove the autoincreme... https://stackoverflow.com performance - Is it possible to drop a primary key index in MySQL ...
If you're sure this is what you want to do (note Paul Tomblin's comment on your question), then from the ALTER TABLE docs: ALTER TABLE `tablename` DROP PRIMARY KEY;. DROP PRIMARY KEY drops the... https://stackoverflow.com How to remove primary key from a mysql table which is primary key ...
You should remove auto_increment first and then drop the primary key.. so try this: ALTER TABLE `mytable` CHANGE ... you need remove the FK s before. On MySQL, do like this: ALTER TABLE `table_name` ... https://stackoverflow.com Updating MySQL primary key - Stack Overflow
create table fixit (user_2, user_1, type, timestamp, n, primary key( user_2, user_1, type) ); lock table fixit write, user_interactions u write, user_interactions write; insert into fixit select user... https://stackoverflow.com indexing - MySQL dropping all indexes from table - Stack Overflow
list all non-unique indexes SELECT table_name AS `Table`, index_name AS `Index`, GROUP_CONCAT(column_name ORDER BY seq_in_index) AS `Columns` FROM information_schema.statistics WHERE NON_UNIQUE = 1 A... https://stackoverflow.com indexing - How to drop this index in MySQL? - Stack Overflow
Run this command in the mysql client: mysql> SHOW CREATE TABLE listings;. It will show you the DDL for the table, including the system-assigned name for the index. https://stackoverflow.com mysql 建立索引刪除索引查看索引@ hsiung.博格ERP軟體:: 隨意窩Xuite ...
mysql 建立索引刪除索引查看索引使用索引，能夠提高查詢的速度 1、建立索引1)ALTERTABLE 創建普通索引，UNIQUE索引或者PRIMARY KEY索引ALTER TABLE table_name ADD INDEX index_name(column_list) ALTER TABLE table_name ADD UNIQUE(column_list) ALTER TABLE ta... http://blog.xuite.net MySQL Drop Primary Key from a MySQL Database Table via the Alter ...
The RazorSQL alter table tool includes a Drop Primary Key option for dropping a primary key from a MySQL database table. The drop primary key function generates the appropriate alter table drop primar... http://razorsql.com |