Query Operators

Query Operators

Modified by Jason Howie on May 15, 2018

Contents

Arithmetic Operators
Logical Operators
Comparison Operators
Wild Card Characters
Boolean Strings
Brackets and Order of Precedence

This page provides a summary of the operators that can be used when defining logical query expressions with the Query Language.

Arithmetic Operators

Operator	Description	Example
+	Addition operator	`NetPinCount + NetViaCount`
-	Subtraction operator	`ArcStopAngle - ArcStartAngle`
*	Multiplication operator	`PadXSize_BottomLayer * PadYSize_BottomLayer`
/	Division operator	`HoleDiameter / ViaDiameter`
Div	Integral division operator	`Color Div 65536` This calculates Color divided by 65536 and the fractional part of the result is discarded
Mod	Modulus operator	`Color Mod 256` This calculates the remainder when Color is divided by 256, without determining the fractional part of the result

Logical Operators

Operator	Description	Example
And	Logical AND operator	`IsPad And OnMultiLayer` To be returned, an object has to be a pad, and reside on the Multi-Layer layer
&&	Logical AND operator (lower precedence)	`IsPad && OnMultiLayer` To be returned, an object has to be a pad, and reside on the Multi-Layer layer
Or	Logical OR operator	`IsPad Or IsVia` To be returned, an object has to either be a pad, or a via
\|\|	Logical OR operator (lower precedence)	`IsPad \|\| IsVia` To be returned, an object has to either be a pad, or a via
Xor	Logical EXCLUSIVE OR operator	`OnMultiLayer Xor (HoleDiameter <> 0)` To be returned, an object has to either be on the Multi-Layer layer and have a Hole Diameter that is zero, or not be on the Multi-Layer layer and have a Hole Diameter that is not zero.
Not	Logical NOT operator	`Not OnMultiLayer` To be returned, an object has to not be on the Multi-Layer layer

Comparison Operators

Operator	Description	Example
<	Less Than operator	`HoleDiameter < 40` To be returned, an object has to have a Hole Diameter which is less than 40
<=	Less Than Or Equal To operator	`HoleDiameter <= 40` To be returned, an object has to have a Hole Diameter which is less than, or equal to 40
>=	Greater Than Or Equal To operator	`HoleDiameter >= 40` To be returned, an object has to have a Hole Diameter which is greater than, or equal to 40
>	Greater Than operator	`HoleDiameter > 40` To be returned, an object has to have a Hole Diameter which is greater than 40
<>	Not Equal To operator	`HoleDiameter <> 40` To be returned, an object has to have a Hole Diameter which is not equal to 40
=	Equal To operator	`HoleDiameter = 40` To be returned, an object has to have a Hole Diameter which is equal to 40
Between...And...	Inclusive range operator	`HoleDiameter Between 30 And 50` To be returned, an object has to have a Hole Diameter that is greater than, or equal to 30, and less than, or equal to 50.
Like	Like operator	`Name Like 'ADDR?'` This returns objects having a Name* property whose associated (text) string begins with `ADDR` and which contains at least one more character

Wild Card Characters

Wild Card characters permit the provision of strings which are not exactly specified. These characters are typically used in conjunction with other characters, resulting in the provision of strings which are partially specified. A few exceptional keywords can accept string parameters that are not exactly specified, but for the most part, strings can only contain Wild Card characters when these are being compared by the Like operator.

Operator	Description	Example
?	This can be replaced by a single character of any type	`Footprint Like 'DIP1?'` This returns objects which have a Footprint property of `DIP10`, or `DIP12`, or `DIP14`, etc.
*	This can be replaced by any number of characters, each of which can be of any type	`Footprint Like 'SIP'` This returns objects which have a Footprint* property of `SIP1`, or `SIP12`, or `SIP216`, etc. (Any objects having a Footprint property of `SIP` are also returned, because '*' can also be replaced by no characters)

Boolean Strings

Operator	Description	Example
True	This affirms the meaning of a Keyword	`IsPad = True` To be returned, an object has to be a pad
False	This negates the meaning of a Keyword	`IsVia = False` To be returned, an object has to not be a via

Brackets and Order of Precedence

It is worthwhile taking a look at the order of precedence in place for the operators used in logical Query expressions. After all, without such knowledge, an expression may not target the objects required.

Brackets have the highest precedence within an order of precedence that has been defined for the various operators, and which determines how queries are interpreted by the software (whenever the user has not provided brackets). The sequence of this order, from highest to lowest, is as follows:

Brackets
Not
^, *, /, Div, Mod, And
+, -, Or, Xor
=, <>, <, >, <=, >=
&&, ||

This order of precedence is similar to that used in Pascal-type languages. Ambiguities are resolved by working from left to right. Brackets are evaluated from inside to outside and equal levels are evaluated left to right.

It is highly advisable to use brackets whenever there is any possibility, whatsoever, that the query might not be correctly interpreted. Generous usage of brackets removes doubt and makes the resulting queries easier to read by others.

印刷

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