SQL INTERVIEW QUESTION & ANSWERS
| 41. |
Define Unique Constraint? |
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The UNIQUE constraint imposes that every value in a column or set of columns be unique. It means that no two rows of a table can have duplicate values in a specified column or set of columns.
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| 42. |
What statement is used to remove a database privilege? |
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The REVOKE statement is used to remove database privileges. |
| 43. |
What is Snapshot? |
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The data in the database at a particular moment is known as Database State or Snapshot of the Database. |
| 44. |
What is Weak entity type? |
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Entity types that do not have key attribute of their own are called Weak entity type.
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| 45. |
What are the various Date data types available in SQL? |
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- TIME STAMP
- LOB
- BLOB
- CLOB
- BFILE
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