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To change the data type of a column in a table, use the following syntax: SQL Server / MS Access: ALTER TABLE table_name. ALTER COLUMN column_name datatype; My SQL / Oracle (prior version 10G): ALTER TABLE table_name. MODIFY COLUMN column_name datatype; Oracle 10G and later: ALTER TABLE table_name.
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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;
ALTER TABLE modifies a table definition by altering, adding, or dropping columns and constraints. ALTER TABLE also reassigns and rebuilds partitions, or disables and enables constraints and triggers.
To modify the structure of a table, you use the ALTER TABLE statement. The ALTER TABLE statement allows you to perform the following operations on an existing table: Add a new column using the ADD clause. Modify attribute of a column such as constraint, default value, etc. using the MODIFY clause. Remove columns using the DROP clause.
This SQL tutorial explains how to use the SQL ALTER TABLE statement to add a column, modify a column, drop a column, rename a column or rename a table (with lots of clear, concise examples).
To rename a table in SQL Server, use the sp_rename command: exec sp_rename 'schema.old_table_name', 'new_table_name'
ALTER TABLE changes the structure of a table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or the table itself. You can also change characteristics such as the storage engine used for the table or the table comment.
