How do I find column constraints in SQL Server?

How do I view constraints in Oracle SQL

The column constraint_name contains the name of the constraint, the column constraint_type indicates the type of constraint, and the column table_name contains the name of the table to which the constraint belongs in Oracle.

What is a constraint name in SQL

Constraints are used to limit the types of data that can be entered into a table, ensuring the accuracy and reliability of the data in the table. If there is any violation between the constraint and the data action, the action is aborted. SQL constraints are used to specify rules for the data in a table.

What are the different locks in SQL Server

Locking is the way that SQL Server manages transaction concurrency.
At the table level, there are five different types of locks:

• Specifically (X)
• Combined (C)
• Exclusive in intent (IX)
• Shared Intent (IS)
• Exclusively shared with (SIX)

What are different types of constraints

An informational constraint is an attribute of a certain type of constraint, but the attribute is not enforced by the database manager.

• NOT NULL restrictions.
• specific limitations.
• main key restrictions.
• Check constraints in the table.
• constraints on foreign keys (referential).
• constraints on the information.

What is constraint foreign key

A FOREIGN KEY is a field (or collection of fields) in one table that refers to the PRIMARY KEY in another table. This relationship between the two tables is protected by the FOREIGN KEY constraint.

What is a foreign key column

Foreign key constraints enforce referential integrity, which essentially states that if column value A refers to column value B, then column value B must exist. A foreign key is a column (or combination of columns) in a table whose values must match values of a column in some other table.

How do you drop a foreign key in a column in SQL

To delete a foreign key constraint

1. Expand the constraint table in Object Explorer, then expand Keys.
2. Click Delete after performing a right-click on the restriction.
3. Click OK in the Delete Object dialog box.

What is default constraint in SQL Server

If no other value is specified, the default value of a column set using the DEFAULT constraint will be added to all new records.

How do you add constraints to a table

This syntax fragment is part of the ALTER TABLE statement. Use the ADD CONSTRAINT clause to specify a primary key, foreign key, referential, unique, or check constraint on a new or existing column or on a set of columns. Notes: For NULL and NOT NULL constraints, use instead the MODIFY Clause.

What is primary key constraint in SQL

A table can have only ONE primary key, and this primary key in the table can consist of one or more columns (fields), and the PRIMARY KEY constraint ensures that each record in the table is uniquely identified. Primary keys must contain UNIQUE values and cannot contain NULL values.

How do you rename a constraint in SQL

When a PRIMARY KEY or UNIQUE constraint is renamed, sp_rename automatically renames the associated index. If a renamed index is tied to a PRIMARY KEY constraint, sp_rename also automatically renames the PRIMARY KEY constraint. sp_rename can be used to rename primary and secondary XML indexes.

How can remove primary key constraint in SQL Server

To delete a primary key constraint using Object Explorer

1. Expand the table that the primary key is located in, then expand Keys in Object Explorer.
2. Delete can be chosen by right-clicking the key.
3. Make sure the correct key is specified in the Delete Object dialog box, then click OK.