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What is the command to modify the table structure in sql statement?

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Release: 2019-06-19 16:05:44
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What is the command to modify the table structure in sql statement?

The command in the SQL statement to modify the table structure is ALTER TABLE.

ALTER TABLE statement

The ALTER TABLE statement is used to add, delete, or modify columns in an existing table.

SQL ALTER TABLE syntax

To add columns to the table, please use the following syntax:

ALTER TABLE table_name
ADD column_name datatype
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To delete columns in the table, please use the following syntax (Please note that some database systems do not allow this way of deleting columns in database tables):

ALTER TABLE table_name
DROP COLUMN column_name
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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
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My SQL / Oracle:

ALTER TABLE table_name
MODIFY COLUMN column_name datatype
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Oracle 10G and later versions:

ALTER TABLE table_name
MODIFY column_name datatype;
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For more SQL-related technical articles, please visit SQL tutorial column to learn!

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