Use ALTER TABLE to change the column type : Alter Table « Table Index « SQL / MySQL






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Use ALTER TABLE to change the column type

     
mysql> CREATE TABLE news
    -> (
    -> id INT UNSIGNED NOT NULL AUTO_INCREMENT,
    -> article BLOB NOT NULL,
    -> PRIMARY KEY (id)
    -> );
Query OK, 0 rows affected (0.01 sec)

mysql>
mysql> ALTER TABLE news MODIFY article TEXT NOT NULL;
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> ALTER TABLE news CHANGE article article TEXT NOT NULL;
Query OK, 0 rows affected (0.01 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql>
mysql> drop table news;
Query OK, 0 rows affected (0.00 sec)

mysql>








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18.The Effect of ALTER TABLE on Null and Default Value Attributes
19.Create the table and then set the initial sequence value with ALTER TABLE
20.Alter table to set the primary key start
21.ALTER TABLE statement modifies the table accordingly
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24.Two ALTER TABLE statements can be combined
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26.Syntax for Altering a Column
27.Syntax for altering table and delete a Column
28.Storing Altered Character Strings
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31.Use the asterisk to try matching against the name ian or the alternative spelling, iain.
32.Specifying Multiple Alterations
33.Alter table to add an index
34.Alter table to add unique index
35.Alter table to Delete an Index
36.Alter table to add index
37.To drop an index with ALTER TABLE
38.Reduce the number of significant characters per index in the index to the first 16 characters
39.Add IGNORE to the statement, then use SELECT to have a look at the table contents to see how the duplicates ha
40.Change j from INT to BIGINT
41.MODIFY statement should specify the null and default value attributes explicitly
42.Redefine i to be NOT NULL, then try again
43.Change column definition