Modify Table Structure in MySQL -- add and delete Fields

Modifying the table structure in MySQL includes many functions. The following describes how to modify the table structure in MySQL to add and delete fields. If you are interested in modifying the table structure in MySQL, take a look.

Modify Table Structure in MySQL -- add fields:

Alter table 'user _ movement_log'
Add column GatewayId int not null default 0 AFTER 'regionid' (AFTER which field is added)

Modify Table Structure in MySQL -- delete fields:

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;

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