Mysql changes the table structure: add, delete, modify, and adjust the field order to add a field: altertable 'user _ movement_log 'AddcolumnGatewayIdintnotnulldefault0AFTER 'regionid' (after which field is added) Delete the field: altertable 'user _ movement_log 'dropcolumnGatewayi
Mysql changes the table structure: add, delete, modify fields, adjust the field order to add fields: alter table 'user _ movement_log 'Add column GatewayId int not null default 0 AFTER 'regionid' (AFTER which field is added) delete field: alter table 'user _ movement_log' drop column Gatewayi
Mysql changes the table structure: adding, deleting, modifying, and adjusting the field order
Add field:
Alter table 'user _ movement_log'
Add column GatewayId int not null default 0 AFTER 'regionid' (AFTER which field is added)
Delete field:
Alter table 'user _ movement_log 'drop column Gatewayid
Adjust the field order:
Alter table 'user _ movement_log 'CHANGE 'gatewayid' int not null default 0 AFTER RegionID
// Primary key
Alter table tabelname add new_field_id int (5) unsigned default 0 not null auto_increment, add primary key (new_field_id );
// Add a new column
Alter table t2 add d timestamp;
Alter table infos add ex tinyint not null default '0 ';
// Delete a column
Alter table t2 drop column c;
// Rename a column
Alter table t1 change a B integer;
// Change the column type
Alter table t1 change B bigint not null;
Alter table infos change list tinyint not null default '0 ';
// Rename the table
Alter table t1 rename t2;
Add Index
Mysql> alter table tablename change depno int (5) not null;
Mysql> alter table tablename add index name (field name 1 [, field name 2…]);
Mysql> alter table tablename add index emp_name (name );
Index with primary keywords
Mysql> alter table tablename add primary key (id );
Add an index with unique conditions
Mysql> alter table tablename add unique emp_name2 (cardnumber );
Delete An index
Mysql> alter table tablename drop index emp_name;
Modify Table:
Add field:
Mysql> alter table table_name ADD field_name field_type;
Modify the original field name and type:
Mysql> alter table table_name CHANGE old_field_name new_field_name field_type;
Delete field:
Mysql> alter table table_name DROP field_name;