alter

I want to change the datatype of some primary-key columns in my database from INT to BIGINT. The following definition is a toy-example to illustrate the problem: CREATE TABLE IF NOT EXISTS `owner` ( `id` int(11) NOT NULL AUTO_INCREMENT, `thing_id` int(11) NOT NULL, PRIMARY KEY (`id`), KEY `thing_id` (`thing_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ; DROP TABLE IF EXISTS `thing`; CREATE TABLE IF NOT EXISTS `thing` ( `id` int(11) NOT NULL AUTO_INCREMENT, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ;

I have two fields i need to increment the character limit on. I're read through the documentation and to my surprise i found no option for it. Is it possible to do? If not, how should i go about solving this? I could drop the column and re-create it with the correct properties, but i don't want to loose any data in the database. Use Raw Queries : /** * Make changes to the database. * * @return void */ public function up() { DB::query('ALTER TABLE mytable MODIFY mycolumn VARCHAR(new-length)'); } /** * Revert the changes to the database. * * @return void */ public function down() { DB::query(

I would like to write a single SQL command to drop multiple columns from a single table in one ALTER TABLE statement. From MSDN's ALTER TABLE documentation ... DROP { [CONSTRAINT] constraint_name | COLUMN column_name } Specifies that constraint_name or column_name is removed from the table. DROP COLUMN is not allowed if the compatibility level is 65 or earlier. Multiple columns and constraints can be listed. It says that mutliple columns can be listed in the the statement but the syntax doesn't show an optional comma or anything that would even hint at the syntax. How should I write my SQL to

I have a database and I want to create a table with COUNT function in it. Is it possible ? I have 3 existing tables: Member Feedback Attendance In Feedback table, 2 columns Class_ID, Likes (Class_ID link with the attendance, as each member attend 1 class eg. class 1,2,3,etc. and Likes is for the number of people like the class). In Attendance table, 3 columns: Class_ID Member_ID Non_member_name Now I want to alter Feedback table to add 2 new columns. One to count the number of people attend the class, e.g if there is 4 people attend class 1,there would be 4 rows of Class_ID=1. Two to count the

Initially, the table "MyTable" has been defined in the following way: CREATE TABLE IF NOT EXISTS `MyTable` ( `Col1` smallint(6) NOT NULL AUTO_INCREMENT, `Col2` smallint(6) DEFAULT NULL, `Col3` varchar(20) NOT NULL, ); How to update it in such a way that the column "Col 3" would be allowed to be NULL? Tschareck The following MySQL statement should modify your column to accept NULLs. ALTER TABLE `MyTable` ALTER COLUMN `Col3` varchar(20) DEFAULT NULL ALTER TABLE MyTable MODIFY Col3 varchar(20) NULL; 来源： https://stackoverflow.com/questions/10597982/alter-sql-table-allow-null-column-value