What are SQL constraints?

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kumar BI

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Aug 04, 2020 11:09 am

(@kumar BI)

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SQL Constraints

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Ram DBA

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Aug 05, 2020 4:07 am

(@Ram DBA)

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SQL constraints are the set of rules that impose some restrictions while insertion, deletion, or updating of data in the databases.

In SQL we have both column level as well as table level constraints which are applied at columns and tables respectively. Some of the constraints in SQL are as follows.

Primary Key
Foreign Key
Unique Key
Not NULL
DEFAULT
CHECK
Index