Union (SQL)

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In SQL the UNION operator combines the results of two SQL queries into a single table of all matching rows. The two queries must have matching fields and data types in order to join them. Any duplicate records are automatically removed.

See also

• Union (set theory)

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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