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Drop (SQL)

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A DROP statement in SQL removes an object from a relational database management system (RDBMS). The types of objects that can be dropped depends on which RDBMS is being used, but most support the dropping of tables, users, and databases. Some systems (such as PostgreSQL) allow DROP and other DDL commands to occur inside of a transaction and thus be rolled back.

The typical usage is simply DROP objecttype objectname. For example, the command to drop a table named employees would be:

DROP TABLE employees;
The DROP statement is distinct from the DELETE statement. For example, a DELETE statement might delete some (or all) data from a table, whereas a DROP statement might remove the entire table from the database.
Topics in database management systems (DBMS)[ view][ talk][ edit] )
Concepts
Database | Database model | Relational database | Relational model | Relational algebra | Primary key - Foreign key - Surrogate key - Superkey
Database normalization | Referential integrity | Relational DBMS | Distributed DBMS | ACID

Objects
Trigger | View | Table | Cursor | Log | Transaction | Index | Stored procedure | Partition
Topics in SQL
Select | Insert | Update | Merge | Delete | Join | Union | Create | Drop
Comparison of syntax

Implementations of database management systems
Types of implementations
Flat file | Deductive | Dimensional | Hierarchical | Object oriented | Temporal

Products
dBASE | Oracle | Sybase | MySQL | Microsoft SQL Server | PostgreSQL | DB2 | Comparison - relational | Comparison - object-relational
Components
Query language | Query optimizer | Query plan | ODBC | JDBC
Lists
List of object-oriented database management systems
List of relational database management systems
List of truly relational database management systems

 


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