Operators

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Operators manipulate individual data items (operands) and return a result. Mimer SQL uses the following operators:

• Set Operators
• Arithmetical Operators
• Comparison and Relational Operators
• Logical Operators.

Set Operators

UNION or UNION ALL

Derives a final result set by combining two other result sets.

If you specify UNION ALL, the result consists of all rows in both results sets.

If you only specify UNION, the final result set is the set of all rows in both of the result sets, with duplicate rows removed.

Arithmetical Operators

Arithmetical operators are used in forming expressions, see Expressions.

The operators are:

• unary arithmetical
• binary arithmetical

Unary Arithmetical

+	leaves operand unchanged
-	changes sign of operand

Binary Arithmetical

+	addition
-	subtraction
*	multiplication
/	division

String Operators

String operators are used in forming expressions, see Expressions.

String

||	concatenation

Comparison and Relational Operators

Comparison operators are used to compare operands in basic and quantified predicates. Relational operators are used to compare operands in all other predicates. See Predicates.

Both comparison and relational operators perform essentially similar functions. However, comparison operators are common to most programming languages, while the relational operators are more or less specific to SQL.

Comparison Operators

Comparison operator	Explanation
=	equal to
<>	not equal to
<	less than
<=	less than or equal to
>	greater than
>=	greater than or equal to

Quantifiers

Quantifier
ALL
SOME
ANY

Relational Operators

Relational operator
BETWEEN
EXISTS
IN
IS
LIKE
OVERLAPS

Logical Operators

Logical operator
AND
OR
NOT

The operators AND and OR are used to combine several predicates to form search conditions, see Search Conditions.

The operator NOT may be used to reverse the truth value of a predicate in forming search conditions. This operator is also available in predicate constructions to reverse the function of a relational operator, see Search Conditions.

Standard Compliance

This section summarizes standard compliance concerning operators.

Standard	Compliance	Comments
SQL-2003	Core	Fully compliant.

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