SQL constraints are used to specify rules for data in a table.SQL Create ConstraintsConstraints can be specified when the table is created with the CREATE TABLE statement, or after the table is created with the ALTER TABLE statement.Syntax...
To create new tables in a database To manage SQL user permissionsSubmit Answer » What is an Exercise? Test what you learned in the chapter: SQL Constraints by completing 5 relevant exercises. To try more SQL Exercises please visit our SQL Exercises page....
TheALTER TABLEcommand also adds and deletes various constraints in a table. The following SQL adds an "Email" column to the "Customers" table: Example ALTERTABLECustomers ADDEmail varchar(255); Try it Yourself » The following SQL deletes the "Email" column from the "Customers" table: ...
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.ADD COLUMNWe want to add a column named color to our cars table....
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