CBLQueryFunction Class Reference
CBLQueryFunction
@interface CBLQueryFunction : NSObjectCBLQueryFunction provides query functions.
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Creates an AVG(expr) function expression that returns the average of all the number values in the group of the values expressed by the given expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)avg:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe expression.
Return Value
The AVG(expr) function.
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Creates a COUNT(expr) function expression that returns the count of all values in the group of the values expressed by the given expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)count:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe expression.
Return Value
The COUNT(expr) function.
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Creates a MIN(expr) function expression that returns the minimum value in the group of the values expressed by the given expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)min:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe expression.
Return Value
The MIN(expr) function.
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Creates a MAX(expr) function expression that returns the maximum value in the group of the values expressed by the given expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)max:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe expression.
Return Value
The MAX(expr) function.
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Creates a SUM(expr) function expression that return the sum of all number values in the group of the values expressed by the given expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)sum:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe expression.
Return Value
The SUM(expr) function.
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Creates an ABS(expr) function that returns the absolute value of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)abs:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The ABS(expr) function.
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Creates an ACOS(expr) function that returns the inverse cosine of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)acos:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The ACOS(expr) function.
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Creates an ASIN(expr) function that returns the inverse sin of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)asin:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The ASIN(expr) function.
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Creates an ATAN(expr) function that returns the inverse tangent of the numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)atan:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The ATAN(expr) function.
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Creates an ATAN2(Y, X) function that returns the arctangent of y/x.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)atan2:(nonnull CBLQueryExpression *)y x:(nonnull CBLQueryExpression *)x;Parameters
yThe expression to evaluate as the Y coordinate.
xThe expression to evaluate as the X coordinate.
Return Value
The ATAN2(Y, X) function.
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Creates a CEIL(expr) function that returns the ceiling value of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)ceil:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The CEIL(expr) function.
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Creates a COS(expr) function that returns the cosine of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)cos:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The COS(expr) function.
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Creates a DEGREES(expr) function that returns the degrees value of the given radiants value expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)degrees: (nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression to evaluate as a radiants value.
Return Value
The DEGREES(expr) function.
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Creates a E() function that return the value of the mathemetical constant ‘e’.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)e;Return Value
The E() constant function.
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Creates a EXP(expr) function that returns the value of ‘e’ power by the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)exp:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The EXP(expr) function.
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Creates a FLOOR(expr) function that returns the floor value of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)floor:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The FLOOR(expr) function.
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Creates a LN(expr) function that returns the natural log of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)ln:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The LN(expr) function.
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Creates a LOG(expr) function that returns the base 10 log of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)log:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The LOG(expr) function.
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Creates a PI() function that returns the mathemetical constant Pi.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)pi;Return Value
The PI() constant function.
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Creates a POWER(base, exponent) function that returns the value of the given base expression power the given exponent expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)power:(nonnull CBLQueryExpression *)base exponent:(nonnull CBLQueryExpression *)exponent;Parameters
baseThe base expression.
exponentThe exponent expression.
Return Value
The POWER(base, exponent) function.
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Creates a RADIANS(expr) function that returns the radians value of the given degrees value expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)radians: (nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression to evaluate as a degrees value.
Return Value
The RADIANS(expr) function.
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Creates a ROUND(expr) function that returns the rounded value of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)round:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The ROUND(expr) function.
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Creates a ROUND(expr, digits) function that returns the rounded value to the given number of digits of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)round:(nonnull CBLQueryExpression *)expression digits:(nonnull CBLQueryExpression *)digits;Parameters
expressionThe numeric expression.
digitsThe number of digits.
Return Value
The ROUND(expr, digits) function.
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Creates a SIGN(expr) function that returns the sign (1: positive, -1: negative, 0: zero) of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)sign:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The SIGN(expr) function.
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Creates a SIN(expr) function that returns the sin of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)sin:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The SIN(expr) function.
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Creates a SQRT(expr) function that returns the square root of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)sqrt:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The SQRT(expr) function.
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Creates a TAN(expr) function that returns the tangent of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)tan:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The TAN(expr) function.
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Creates a TRUNC(expr) function that truncates all of the digits after the decimal place of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)trunc:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric expression.
Return Value
The trunc function.
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Creates a TRUNC(expr, digits) function that truncates the number of the digits after the decimal place of the given numeric expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)trunc:(nonnull CBLQueryExpression *)expression digits:(nonnull CBLQueryExpression *)digits;Parameters
expressionThe numeric expression.
digitsThe number of digits.
Return Value
The TRUNC(expr, digits) function.
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Creates a CONTAINS(expr, substr) function that evaluates whether the given string expression conatins the given substring expression or not.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *) contains:(nonnull CBLQueryExpression *)expression substring:(nonnull CBLQueryExpression *)substring;Parameters
expressionThe string expression.
substringThe substring expression.
Return Value
The CONTAINS(expr, substr) function.
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Creates a LENGTH(expr) function that returns the length of the given string expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)length:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe string expression.
Return Value
The LENGTH(expr) function.
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Creates a LOWER(expr) function that returns the lowercase string of the given string expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)lower:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe string expression.
Return Value
The LOWER(expr) function.
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Creates a LTRIM(expr) function that removes the whitespace from the beginning of the given string expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)ltrim:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe string expression.
Return Value
The LTRIM(expr) function.
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Creates a RTRIM(expr) function that removes the whitespace from the end of the given string expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)rtrim:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe string expression.
Return Value
The RTRIM(expr) function.
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Creates a TRIM(expr) function that removes the whitespace from the beginning and ‘ the end of the given string expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)trim:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe string expression.
Return Value
The TRIM(expr) function.
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Creates a UPPER(expr) function that returns the uppercase string of the given string expression.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)upper:(nonnull CBLQueryExpression *)expression;Parameters
expressionThe string expression.
Return Value
The UPPER(expr) function.
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Creates a STR_TO_MILLIS(expr) function that returns the number of milliseconds since the unix epoch of the given ISO 8601 date time string expression.
Note
Valid date strings must start with a date in the form YYYY-MM-DD (time only strings are not supported).Times can be of the form HH:MM, HH:MM:SS, or HH:MM:SS.FFF. Leading zero is not optional (i.e. 02 is ok, 2 is not). Hours are in 24-hour format. FFF represents milliseconds, and trailing zeros are optional (i.e. 5 == 500).
Time zones can be in one of three forms: (+/-)HH:MM (+/-)HHMM Z (which represents UTC)
No time zone present will default to the device local time zone.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)stringToMillis: (nonnull CBLQueryExpression *)expression;Parameters
expressionThe validly formatted ISO 8601 date time string expression.
Return Value
The corresponding function that converts the date time string to timestamp.
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Creates a STR_TO_UTC(expr) function that returns the ISO 8601 UTC datetime string of the given ISO 8601 date time string expression.
Note
Valid date strings must start with a date in the form YYYY-MM-DD (time only strings are not supported).Times can be of the form HH:MM, HH:MM:SS, or HH:MM:SS.FFF. Leading zero is not optional (i.e. 02 is ok, 2 is not). Hours are in 24-hour format. FFF represents milliseconds, and trailing zeros are optional (i.e. 5 == 500).
Time zones can be in one of three forms: (+/-)HH:MM (+/-)HHMM Z (which represents UTC)
No time zone present will default to the device local time zone.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *)stringToUTC: (nonnull CBLQueryExpression *)expression;Parameters
expressionThe validly formatted ISO 8601 date time string expression.
Return Value
The corresponding function that converts the string to UTC string.
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Creates a MILLIS_TO_STR(expr) function that returns a ISO 8601 date time string in device local timezone of the given number of milliseconds since the unix epoch expression.
Note
If the input expression is not numeric, then the result will be null.Declaration
Objective-C
+ (nonnull CBLQueryExpression *)millisToString: (nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric value representing milliseconds since the unix epoch.
Return Value
The corresponding function that converts the timestamp to the ISO 8601 date string.
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Creates a MILLIS_TO_UTC(expr) function that returns the UTC ISO 8601 date time string of the given number of milliseconds since the unix epoch expression.
Note
If the input expression is not numeric, then the result will be null.Declaration
Objective-C
+ (nonnull CBLQueryExpression *)millisToUTC: (nonnull CBLQueryExpression *)expression;Parameters
expressionThe numeric value representing milliseconds since the unix epoch.
Return Value
The corresponding function that converts the timestamp into the UTC ISO 8601 string.
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Not available
Declaration
Objective-C
- (nonnull instancetype)init;
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ENTERPRISE EDITION ONLY
Creates prediction function with the given model name and input. When running a query with the prediction function, the corresponding predictive model registered to CBLDatabase class will be called with the given input to predict the result.
The prediction result returned by the predictive model will be in a form dictionary object. To create an expression that refers to a property in the prediction result, the -property: method of the created CBLQueryPredictionFunction object can be used.
Declaration
Objective-C
+ (nonnull CBLQueryPredictionFunction *) predictionUsingModel:(nonnull NSString *)model input:(nonnull CBLQueryExpression *)input;Parameters
modelThe predictive model name registered to the CouchbaseLite Database.
inputThe expression evaluated to a dictionary.
Return Value
A CBLQueryPredictionFunction object.
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ENTERPRISE EDITION ONLY
Creates a function that returns the euclidean distance between the two input vectors. The result is a non-negative floating-point number. The expression1 and expression2 must be arrays of numbers, and must be the same length.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *) euclideanDistanceBetween:(nonnull CBLQueryExpression *)expression1 and:(nonnull CBLQueryExpression *)expression2;Parameters
expression1The expression evaluated to an arrays of numbers.
expression2The expression evaluated to an arrays of numbers.
Return Value
The euclient distance between two given input vectors.
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ENTERPRISE EDITION ONLY
Creates a function that returns the squared euclidean distance between the two input vectors. The result is a non-negative floating-point number. The expression1 and expression2 must be arrays of numbers, and must be the same length.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *) squaredEuclideanDistanceBetween:(nonnull CBLQueryExpression *)expression1 and:(nonnull CBLQueryExpression *)expression2;Parameters
expression1The expression evaluated to an arrays of numbers.
expression2The expression evaluated to an arrays of numbers.
Return Value
The squared euclient distance between two given input vectors.
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ENTERPRISE EDITION ONLY
Creates a function that returns the cosine distance which one minus the cosine similarity between the two input vectors. The result is a floating-point number ranges from −1.0 to 1.0. The expression1 and expression2 must be arrays of numbers, and must be the same length.
Declaration
Objective-C
+ (nonnull CBLQueryExpression *) cosineDistanceBetween:(nonnull CBLQueryExpression *)expression1 and:(nonnull CBLQueryExpression *)expression2;Parameters
expression1The expression evaluated to an arrays of numbers.
expression2The expression evaluated to an arrays of numbers.
Return Value
The cosine distance between two given input vectors.