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9 Ιαν 2016 · CREATE TABLE Product ( product_id INT NOT NULL PRIMARY KEY IDENTITY , product_code CHAR(4) NOT NULL , product_name VARCHAR(40) NOT NULL , product_desc VARCHAR(5000) , book_author INT , book_publisher INT , product_price SMALLMONEY NOT NULL CHECK (product_price >= 0) , CONSTRAINT CHK_author CHECK ( CASE WHEN product_code = 'BOOK' AND (book ...
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.
SQL Server allows you to perform the following changes to an existing column of a table: Modify the data type. Change the size. Add a NOT NULL constraint. Modify column’s data type. To modify the data type of a column, you use the following statement: ALTER TABLE table_name . ALTER COLUMN column_name new_data_type(size);
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.
This tutorial shows you step by step how to use the SQL ALTER TABLE statement to add new columns, modify existing columns, and drop columns from a table.
19 Σεπ 2022 · In this article, we look at how to make changes to SQL Server table structures using T-SQL commands to add, delete and change columns in a table.
22 Σεπ 2021 · We can use ALTER TABLE ALTER COLUMN statement to change the column type of the table. The syntax to change the column type is following: 1. ALTER TABLE [tbl_name] ALTER COLUMN [col_name_1] [DATA_TYPE] In the syntax, Tbl_name: Specify the table name. Col_name: Specify the column name whose datatype you want to change.
