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• Overview
• Keywords and Operators

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Overview

IRSA's Catalog Search Service allows potentially complex constraints to be specified in SQL format in the "Additional Constraints" section of the Query building interface. These include the following classes of constraints:

Keywords and Operators

keyword/operator	description	syntax	example using AllWISE Source Catalog 1000 arcsecond cone search centered on M81
=	Compares two expressions. The result is TRUE if both operands are equal. Otherwise, the result is FALSE.	expression = expression	designation = 'J095824.30+685729.3'
!=	Compares two expressions. The result is TRUE if the left operand is not equal to the right operand. Otherwise, the result is FALSE.	expression != expression	designation != 'J095824.30+685729.3'
<	Compares two expressions. When comparing numeric values, the result is TRUE if the left operand has a lower value than the right operand. When comparing character values, the results is TRUE if the left operand is earlier in the alphabet than the right operand. When comparing dates, the results is TRUE if the left operand is earlier than the right operand. Otherwise, the result is FALSE.	expression < expression	w1mpro < 16 designation < 'J095824.30+685729.3'
<=	Compares two expressions. When comparing numeric values, the result is TRUE if the left operand is less than or equal to the right operand. When comparing character values, the results is TRUE if the left operand is earlier in the alphabet or equal to the right operand. When comparing dates, the results is TRUE if the left operand is earlier or equal to the right operand. Otherwise, the result is FALSE.	expression <= expression	w1mpro<=16 designation<='J095824.30+685729.3'
>	Compares two expressions. When comparing numeric values, the result is TRUE if the left operand is greater than the right operand. When comparing character values, the results is TRUE if the left operand is later in the alphabet than the right operand. When comparing dates, the results is TRUE if the left operand is later than the right operand. Otherwise, the result is FALSE.	expression > expression	w1mpro>16 designation>'J095824.30+685729.3'
>=	Compares two expressions. When comparing numeric values, the result is TRUE if the left operand is greater than or equal to the right operand. When comparing character values, the results is TRUE if the left operand is later in the alphabet or equal to the right operand. When comparing dates, the results is TRUE if the left operand is later than or equal to the right operand. Otherwise, the result is FALSE.	expression >= expression	w1mpro>=16 designation>='J095824.30+685729.3'
NOT	Used to negate an operation.	NOT expression	w2sigmpro IS NOT NULL dec NOT BETWEEN 69 AND 69.1
BETWEEN	Specifies a range to test. BETWEEN returns TRUE if the value of test_expression is greater than or equal to the value of begin_expression and less than or equal to the value of end_expression.	test_expression [ NOT ] BETWEEN begin_expression AND end_expression	ra BETWEEN 148.6 AND 149.2 dec NOT BETWEEN 69 AND 69.1
IN	Determines if a given value matches any value in a subquery or a list.	test_expression [ NOT ] IN ('expression', 'expression', ... , 'expression')	ph_qual IN ('ABUU', 'BUUU', 'BCCU')
LIKE	Determines whether a character string matches a specified pattern. A pattern can include regular characters and wildcard characters. During pattern matching, regular characters must exactly match the characters specified in the character string. Wildcard characters, however, can be matched with arbitrary fragments of the character string. IRSA's Catalog Search Service accepts two wildcards: % (percent; matches any string of >0 characters) _ (underscore; matches any single character) If you would like to include percent or underscore in your pattern, but do not wish them to be interepreted as wildcards, then you may specify an escape character using "ESCAPE escape_parameter".	match_expression [ NOT ] LIKE pattern	designation LIKE 'J0958%' - selects any designation that starts with 'J0958%' designation LIKE '%0958%' - selects any designation with '0958' in it. ph_qual LIKE 'AAA_' - selects any ph_qual with four letters, the first three of which are 'AAA'.
IS [NOT] NULL	An entry of NULL in a data table means that there is no entry (e.g., missing data). NULL is not synonymous with 'zero' or 'blank'. 'NULL' and 'null' are equivalent. If the value of expression is NULL, IS NULL returns TRUE; otherwise, it returns FALSE. If the value of expression is NULL, IS NOT NULL returns FALSE; otherwise, it returns TRUE.	expression IS [ NOT ] NULL	w2sigmpro IS NOT NULL w2sigmpro IS NULL
AND	Combines two expressions and returns TRUE when both expressions are TRUE. When more than one logical operator is used in a statement, AND operators are evaluated first. You can change the order of evaluation by using parentheses.	expression AND expression	(w2sigmpro IS NOT NULL) AND (ra BETWEEN 148.6 AND 149.2)
OR	Combines two conditions. When more than one logical operator is used in a statement, OR operators are evaluated after AND operators. However, you can change the order of evaluation by using parentheses.	expression OR expression	(ra BETWEEN 148.6 AND 149.2) OR (dec NOT BETWEEN 69 AND 69.1)
+	plus	expression + expression
-	minus	expression - expression
/	divided by	expression / expression
*	multiply	expession * expression
%	modulo, the remainder left after division of two numbers.	expression % expression
ABS	Absolute Value	abs(expression)
ACOS	Arc Cosine	acos(expression)
ASIN	Arc Sine	asin(expression)
ATAN	Arc Tangent	atan(expression)
COS	Cosine	cos(expression)
EXP	Returns the exponential value in scientific notation of the argument	exp(expression)	EXP(198.1938327) = 1.18710159597953E+86
FLOOR	Returns the largest integer equal to or less than the specified argument.	floor(expression)	floor(15.7) = 15.
LOG	Logarithm (base 10)	log(10, expression)
POWER	numeric_expr raised to the power of p	power(expression, p)
RAND	Produce a random float number between 0 and 1. When invoked with the optional integer argument, that value will be used to seed the random number generator. For a specified seed value, the result returned is always the same.	rand([integer_expression])	rand() rand(10)
ROUND	Returns the rounded value of the first expression, out to integer_expression digits	round(expression, integer_expression)	ROUND(123.9994, 3)=123.999 ROUND(123.9995, 3)=124.0000 ROUND(150.75, 0)=151.00
SIN	Returns the trigonometric sine of the specified angle, in radians.	sin(expression)
SQRT	Returns the square root of the specified float.	sqrt(expression)
TAN	Returns the trigonometric tangent of the specified angle, in radians.	tan(expression)