The results of two or more component queries can be combined into one result using SET Operators.They combine the output in the vertical manner.
Queries containing SET Operators are called Compound queries.
All SET Operators have equal precedence. If a SQL statement contains multiple SET Operators, the oracle server evaluates them from left (top) to right (bottom).
Different types of SET Operators are
The number of columns and datatypes of the columns being selected must be identical in all the select statements used in the query. The names of the columns need not be identical.
General Syntax:
<Component query>
{UNION | UNION ALL | MINUS | INTERSECT}
<Compnent query>
Queries containing SET Operators are called Compound queries.
All SET Operators have equal precedence. If a SQL statement contains multiple SET Operators, the oracle server evaluates them from left (top) to right (bottom).
Different types of SET Operators are
The number of columns and datatypes of the columns being selected must be identical in all the select statements used in the query. The names of the columns need not be identical.
General Syntax:
<Component query>
{UNION | UNION ALL | MINUS | INTERSECT}
<Compnent query>
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ReplyDeletenice work.
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