This section explains the condition expressions that compare input event items with keywords.
Various conditions can be specified for patterns. Complex conditions, such as searches for partial matches and word searches, can be described for searches.
The following types of pattern search are available:
Classification | Type |
|---|---|
String match specification | |
Prefix match specification | |
Suffix match specification | |
Free Character Specification | |
Character Interval Specification | |
Partial Character Specification | |
Character Range Specification | |
Numeric Range Specification | |
Word match specification | |
Word interval specification | |
Logical conjunction, logical disjunction, and negation in pattern searches | Logical conjunction |
Logical disjunction | |
Negation |
Pattern Search format
The format used by the pattern search is shown below.
Point
A pattern search is enclosed within quotation marks (") or single quotation marks (').
The handling of upper-case and lower-case single-byte alphabetics in search target strings can be specified by the rule definition (ANKmix option). The handling of upper-case and lower-case double-byte alphabetics can be specified by the rule definition (KNJmix option). Refer to "2.9 Options" for information on the ANKmix and KNJmix options.
Note
Quotation marks (") and single quotation marks (') cannot be used together.
Pattern format
Pattern format is shown below.
The format of a pattern search (string) is shown below.
Point
Characters to be excluded as search targets can be specified in rule definitions (SkipChar option). Refer to "2.9 Options" for information on the SkipChar option.
Finds out whether the value of an element node includes the specified keyword.
Example
Search for data that includes the string "Fujitsu" in the element value indicated by /root/text.
/root/text = 'Fujitsu'
Finds out whether the specified keywords exist at the start of an element node's value.
Example
Search for data that begins with the string "Fujitsu" in the element value indicated by /root/text.
/root/text = '^Fujitsu'
Finds out whether the specified keywords exist at the end of an element node's value.
Example
Search for data that ends with the string "Fujitsu" in the element value indicated by /root/text.
/root/text = 'Fujitsu$'
Find out whether the value of an element node and the value of a text node include a keyword that contains free characters.
Free characters included in keywords can be specified in four ways, as shown in the following table.
Symbol | Explanation | Can be used consecutively |
|---|---|---|
. | Any one arbitrary character | Yes |
.? | Zero or one arbitrary character | Yes |
.+ | One or more arbitrary characters | No |
.* | Zero or more arbitrary characters | No |
Note
If symbols that cannot be used consecutively are used consecutively, CEP engine startup fails.
Example
Search for data that includes the strings "Fujitsu" and "company" in the element value indicated by /root/text, provided the number of characters between these strings is 0 or more.
/root/text = 'Fujitsu.*company'
Information
Free character specifications can be combined. The following table shows examples of how combinations of free character specifications evaluate to TRUE or FALSE for different data. These results assume that "=" has been specified as the comparison operator.
Keyword example | Data example | |||
|---|---|---|---|---|
AB | AXB | AYYB | AZZZB | |
'A.' | Y | Y | Y | Y |
'A.B' | x | Y | x | x |
'A.?B' | Y | Y | x | x |
'A.+B' | x | Y | Y | Y |
'A.*B' | Y | Y | Y | Y |
'A..?B' | x | Y | Y | x |
'A..+B' | x | x | Y | Y |
'A..*B' | x | Y | Y | Y |
'A.?.+B' | x | Y | Y | Y |
'A.?.*B' | Y | Y | Y | Y |
Y: TRUE
x: FALSE
Finds out whether the two specified keywords appear in succession in an element node's value within an interval of the specified number of characters. The numeric value of character interval specifications must be from 0 through 1024.
Note
Character interval specifications can only be specified once in string searches.
Free character specifications cannot be specified immediately before or after character interval specifications.
Example
Search for data that includes the strings "alcohol" and "concentration" in the element value indicated by /root/text, provided the number of characters between these strings is 10 or less.
/root/text = 'alcohol,10C,concentration'Finds out whether the value of an element node and the value of a text node contain the specified keyword.
Part of the keyword consists of one of multiple strings.
Note
Depending on the number of characters specified, a large amount of memory can be used. Insufficient memory can cause the search response to deteriorate. Note that, if a memory overflow is detected, an error message is output and the input event is discarded (processing of the next input event continues).
Refer to Section 6.3.4, "Tuning" in the User's Guide for information on the memory estimation method.
Example
Search for data that includes any of the strings-"Jon Smith", "John Smith", or "Jonathon Smith"-in the element value indicated by /root/text.
/root/text = 'Jo(n|hn|nathon) Smith'
Finds out whether the value of an element node includes the specified keyword where part of the keyword consists of any character in a specific range.
The character code value of the start character must be smaller than the character code value of the end character. Both the start character (character 1) and the end character (character 2) must be single ASCII characters and must not be control characters.
Note
Depending on the specified character range, a large amount of memory can be used. Insufficient memory can cause the search response to deteriorate. Note that, if a memory overflow is detected, an error message is output and the input event is discarded (processing of the next input event continues).
Refer to Section 6.3.4, "Tuning" in the User's Guide for information on the memory estimation method.
Example
Search for data that includes the strings "classA", "classB", and "classC" in the element value indicated by /root/text.
/root/text = 'class[A-C]'Finds out whether the value of an element node includes the specified keyword where part of the keyword consists of any numeric value in a specific range.
The start numeric value (numeric value 1) and the end numeric value (numeric value 2) must be specified using single-byte numbers. These values must be from 0 through 999. Also, the start numeric value must be smaller than the end numeric value.
Point
Correct search results can be obtained if characters are specified before and after the numeric value.
Note
Depending on the specified numeric range, a large amount of memory can be used. Insufficient memory can cause the search response to deteriorate. Note that, if a memory overflow is detected, an error message is output and the input event is discarded (processing of the next input event continues).
Refer to Section 6.3.4, "Tuning" in the User's Guide for information on the memory estimation method.
Example
Search for data that includes the strings "alcohol 9%", "alcohol 10%", and "alcohol 11%" in the element values indicated by /root/text.
/root/text = 'alcohol [9,11]%'The format of pattern search (word) is shown below.
Point
The word delimiter character can be specified in the rule definitions (SeparateChar option). Refer to "2.9 Options" for information on the SeparateChar option.
ASCII characters (except for the word delimiter character) can be described in word searches.
Finds out whether the value of an element node and the value of the text node contain any individual words that match the specified keyword. For word searches, strings separated by the delimiter are considered as individual words.
Example
Search for data containing the word "the" in the element value indicated by /root/text.
/root/text = '\<the\>'The string "the" in "mother" will evaluate to FALSE because it occurs within a larger word.
Finds out whether the two keywords appear in succession in an element node's value within an interval of the specified number of words.
Numeric values specified for word interval specifications must be from 0 through 1024.
Example
Search for data that includes the words "search" and "AsIs" in the element value indicated by /root/text, provided the number of words between these two words is 10 or less.
/root/text = '\<search\>,10W,\<AsIs\>'Note
Word interval specifications can be used only once in word searches.
This section explains pattern searches (logical conjunction, logical disjunction, and negation).
Finds out whether the value of element nodes specified in a path expression includes all the specified patterns.
Example
Evaluates to TRUE if the value of the element node represented by '/root/text' includes the strings "fast" and "search".
/root/text = 'fast&search'Finds out whether the value of an element node specified in a path expression includes any of the specified patterns.
Example
Evaluates to TRUE if the value of the element node represented by '/root/text' includes either the string "fast" or the string "search".
/root/text = 'fast|search'
Finds out whether the value of an element node specified in a path expression includes none of the specified patterns.
Example
Evaluates to TRUE if the value of the element node represented by '/root/text' includes neither the string "fast" nor the string "search".
/root/text = '~(fast|search)'
Point
For pattern searches, you can use logical conjunction, logical disjunction, and negation in combination. When this happens, the order of evaluation is Negation > Logical conjunction > Logical disjunction.
Parentheses "(" and ")" may also be used to specify the order of evaluation. Conditions in parentheses are evaluated preferentially.
In a string search, a search is performed for events in which the element value exactly matches the value specified in the string or for events in which the element value is in the size relationship. As strings can be used for size comparisons, string searches can be used to search for mixed values containing both numerals and characters.
The format used by the string search is shown below.
String format is shown below.
A string search involves complete match and size comparison.
Finds out if the value of an element node is equal to the string.
Example
Search for data equivalent to the string "North Sydney, Australia" indicated by the element value in /root/area.
/root/area == 'North Sydney, Australia'This compares the size of the element value with the string in the encoding value, in sequence from the left of the string to the right.
Note
It is not possible to specify the "//" path operator at the end of a path expression when the string exactly matches or when performing a size comparison.
It is not possible to specify the "*" path element at the end of a path expression when the string exactly matches or when performing a size comparison.
It is not possible to specify "$_" in the item expression when the string exactly matches or when performing a size comparison.
When performing a string comparison, any element value to be searched within an XML event must have the same number of digits as the string specified in the keyword.
Point
Characters to be excluded as search targets can be specified in rule definitions (SkipChar option).
The handling of upper-case and lower-case single-byte alphabets in search target strings can be specified by the rule definition (ANKmix option). The handling of upper-case and lower-case double-byte alphabets can be specified by the rule definition (KNJmix option).
Refer to "2.9 Options" for details.
In a numeric search, a search is performed by extracting the numeric part from an element value and searching for events in which the extracted value matches a specified numeric value or for events in which the extracted value is in the size relationship. As the numeric portion of the element value is extracted automatically, this search can be used to extract numeric values that have been written in a variety of ways.
In addition, it is also possible to specify a numeric function on the left side of the comparison operator to perform comparisons with numeric values.
The format used by the numeric search is shown below.
Numeric literal format is shown below.
For numbers, specify a digit from 0 through 9. There is no limit to the number of digits that may be specified.
Spaces may not be specified in a numeric literal, with the exception of spaces in a prefix or suffix.
The first string in the above format found from the element value will be treated as a numeric value.
Any commas (,) appearing in the integer part are ignored. If a decimal point is specified, the decimal places include all characters up to the first instance of a non-numeric character.
Example
This example evaluates to TRUE if the numeric component extracted from the value of the element node represented by '/doc/money' matches 1000.
/doc/money = 1000In the following examples, the value of the element node specified in the path expression contains multiple numeric values. In such cases, only the first numeric value is extracted.
Event A
<money>ABC123,456@789</money>123456 is extracted.
Event B
<money>123456 7890123</money>123456 is extracted.
Event C
<money>1,500yen</money>1500 is extracted.
If the search data does not contain a valid numeric value string, the conditions evaluate to FALSE.
The following search target string does not contain a valid numeric value string.
<money></money>Point
The number of digits in a numeric value specified as the keyword need not match the value of the element node specified in a path expression.
There is no need to make the number of digits in the integer or decimal part of element node values consistent across multiple XML events.
EventA
<money>1000.1</money>EventB
<money>2000.05</money>EventC
<money>10.5</money>Note
The '//' path operator cannot be specified at the end of a path expression when performing numeric search.
The '*' path element cannot be specified at the end of a path expression when performing numeric search.
In numeric search, "$_" cannot be specified as an item expression.
Example
Search for data greater than 1000 in the element value indicated by /root/money.
/root/money > 1000See
Refer to "2.8.3.1 val() Function" for details.
Refer to "2.4.6.2 Numeric Literal" for details.