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ALTER/CREATE

 

WARNING! All the modifications of the table will be done permanently by pressing the"Submit" button. It is recommended to perform as fewer actions per time as possible, using 'Preview' option as well in order to avoid unrecoverable errors.
Refer to Mysql online documentation:
http://www.mysql.com/documentation

CREATE NEW TABLE page appears when the button "Create" was pressed:

Fill in the 'Table Name' and new column attribute fields as needed and press Submit.
Once the table with the first column is created, the ALTER table page will be displayed, prompting to create and edit all the other columns:
It is recommended to create all the columns one by one first, and then start to create the keys. (
See screenshot )
To change any column attribute, or name of the table, make changes in the correspondent forms and press submit.
To add column, type its name, type, attribute and state whether or not it must be placed FIRST or AFTER a particular column:


Checkboxes on the left of the column and key names are used to select the columns and the keys to be dropped.

If the new key consists of more then one column, the column names must be comma separated and typed in the order we want them to appear in the key.

If the PRIMARY KEY must be created and one of its columns to be assigned as
AUTO_INCREMENT , we need to create the primary key first. Then checkboxes 'Auto_increment' will appear against  each column belonging to primary key, only if the column is of an appropriate type and is able to become 'Autoincremented'. Selecting one of  these checkboxes, we create 'Autoincremented' column.
Only one Auto column is allowed in Mysql.

If an error occurs in one of the queries, the execution is aborted immediately. The program will not try to execute any of the following queries. Thus if the last query runs in error,  all the previous ones are already executed!
This is why you should never use 'Back' button of web browser. Because in this case the table may appear as it was before any altering was done.

 

 

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