mysql alter table add column example

Tags: alt duration default after first UIL rename change wordALTER column: Sets or removes the default value for a column (very fast operation) Example: alter table film alter column re

Label:The teammate gave me the statement to modify the data. Always fails to execute. I wonder. For example:Look carefully at this column, and there is nothing special. such as:But it does have a constraint: ' df__his_drug___all_i__04e4bc85 '. Why do we have this constraint???When I finally searched this article, I understood. Because the column ' All_inventory_state ' is assigned a default value when it is

Mysql Statement Change table structure ALTER (ALTER)Original Table A For example: The code is as follows Copy Code CREATE TABLE A (A_a int NOT NULL,A_b int

matched:1 changed:1 warnings:0mysq L [bosco]> SELECT * from t6;+----+| ID |+----+| 1 | | 4 | | |+----+3 rows in Set (0.01 sec) MySQL [bosco]> Show create TABLE t6\g*************************** 1. Row *************************** table:t6create table:create Table ' T6 ' (' id ' int (ten) unsigned not NULL auto_incr Ement, PRIMARY KEY (' id ')) engine=innodb auto_

TABLE.The optional word COLUMN is just a useless phrase that can be ignored. If you use ALTER table Tbl_name RENAME to new_name and do not have any other options, MySQL will simply rename the file with the table Tbl_name. This does not require the creation of temporary tab

table if exists's ', 'XX', 'cc '; -- Modify the table name Rename table student to bbs_student; Alter table bbs_student rename student; Alter table bbs_student Rename to student; -

Mysql batch Add a new column stored procedure in the table, mysql new Generally, for websites with a large access volume, the request log table is created independently on a daily basis. The business needs to

Tags: primary key object des SYS exist ODI one-key cmd atiRecently in the collation of things about MySQL, to write down some things to record, in order to query and browse later, the following are some of the operational skills.Add a table fieldALTER TABLE table1 add transactor varchar (ten) not Null;

The following articles mainly describe the actual operations of modifying the alter TABLE structure in MySQL. If you are interested in the actual operations of modifying the alter TABLE structure in MySQL, you can browse the follo

First, basic usage 1. Add Column ALTER TABLE Tbl_name add col_name type For example, add a column of weight to the pet

For websites with a large access volume, the request log table adds a new column for each table to create a business independently for each table every day. after a long time, the stored procedure is as follows: the log table structure type is tbl_ads_req_20140801 and tbl_ad

SQL Server in the deletion of constrained columns the basic processing method 1. First, you need to delete the key associated with the constraint 2. Delete field Delete constraint statement: ALTER TABLE drop constraint constraint name or key go Delete field statement ' ALTER TABLE

primary key is as follows: 12345678910111213141516171819202122 declare@defnamevarchar(100)declare@cmdvarchar(500)declare@tablenamevarchar(100)declare@keynamevarchar(100)Set@tablename=‘Temp1‘Set@keyname=‘id‘--需要設置的key,分隔select@defname=nameFROMsysobjects soJOIN sysconstraints scONso.id = sc.constidWHEREobject_name(so.parent_obj) = @tablenameandxtype=‘PK‘if @defnameisnotnullbeginselect@cmd=‘alter ta