Search results
30 kwi 2014 · Here's a demo: create table foo (id int primary key); insert into foo values (123), (456), (789); alter table foo add column x int auto_increment, add key (x); select * from foo; +-----+---+. | id | x |. +-----+---+.
The ALTER TABLE statement is used to add, delete, or modify columns in an existing table. The ALTER TABLE statement is also used to add and drop various constraints on an existing table. ALTER TABLE - ADD Column. To add a column in a table, use the following syntax: ALTER TABLE table_name. ADD column_name datatype;
If you want to alter the column details, set default value and add a comment, use this. ALTER TABLE [table_name] MODIFY [column_name] [new data type] DEFAULT [VALUE] COMMENT '[column comment]'
Use MySQL ADD COLUMN clause in the ALTER TABLE statement to add one or more columns to a table.
ALTER TABLE table_name ADD COLUMN column_name column_type; W tym poleceniu zamień „nazwa_tabeli” na nazwę tabeli, do której chcesz dodać nową kolumnę. „nazwa_kolumny” to nazwa, którą chcesz nadać nowej kolumnie, a „typ_kolumny” określa typ danych tej nowej kolumny.
25 sty 2024 · ALTER TABLE table_name ADD COLUMN new_column_name data_type DEFAULT 'default_value'; Replace table_name with the name of your table, new_column_name with the name of the new column, data_type with the MySQL data type for the new column, and 'default_value' with the value you want to set as default.
Table Options. table_options signifies table options of the kind that can be used in the CREATE TABLE statement, such as ENGINE, AUTO_INCREMENT, AVG_ROW_LENGTH, MAX_ROWS, ROW_FORMAT, or TABLESPACE.. For descriptions of all table options, see Section 15.1.20, “CREATE TABLE Statement”.However, ALTER TABLE ignores DATA DIRECTORY and INDEX DIRECTORY when given as table options.
