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Learn how to use the ALTER TABLE statement to add, delete, or modify columns in an existing table. See examples of adding, dropping, and modifying columns in MySQL.
Modyfikacja kolumny w tabeli. Aby zmodyfikować parametry kolumny w istniejącej tabeli wykorzystamy opcję MODIFY polecenia ALTER TABLE. Struktura polecenia: ALTER TABLE nazwa_tabeli MODIFY nazwa_kolumny typ_kolumny; Przykład zastosowania: ALTER TABLE pasazer MODIFY plec varchar (10) NOT NULL;
Learn how to use ALTER TABLE to change the structure of a table in MySQL 8.4. See the syntax, options, and examples for adding, dropping, modifying, or renaming columns, indexes, constraints, and more.
You will learn how to use the MySQL ALTER TABLE statement to add a column, alter a column, rename a column, drop a column and rename a table.
To add a new AUTO_INCREMENT integer column named c: ALTER TABLE t2 ADD c INT UNSIGNED NOT NULL AUTO_INCREMENT, ADD PRIMARY KEY (c); We indexed c (as a PRIMARY. KEY) because AUTO_INCREMENT columns must be indexed, and we declare c as NOT NULL because primary key columns cannot be NULL.
Learn how to use ALTER TABLE statement to add, drop, modify or rename columns and tables in MySQL. See syntax, examples and output for each command.
To add an index on column d and a UNIQUE index on column a: ALTER TABLE t2 ADD INDEX (d), ADD UNIQUE (a); To remove column c: ALTER TABLE t2 DROP COLUMN c; To add a new AUTO_INCREMENT integer column named c: ALTER TABLE t2 ADD c INT UNSIGNED NOT NULL AUTO_INCREMENT, ADD PRIMARY KEY (c); We indexed c (as a PRIMARY.
