Escape characters

Some characters in content integration server queries have special meanings.

For example, the asterisk (*) and question mark (?) are used in content integration server queries as multiple-character and single-character wild cards. To search for a string or word that contains a literal special character, such as a literal asterisk or question mark, you must escape these characters in the query.

For example, to search for the literal value View*Star, you must escape the asterisk in the middle of the string. Use a backslash to escape such characters:

Property search
CompanyName LIKE 'View\*Sta?'
to get
'View*Star'
Full-text search
PHRASE = 'Did you ask why\?'
to get
'Did you ask why?'
PHRASE = 'View\*Star increases ? *'
to get
'View*Star increases a single'
If a backslash (\) needs to be included in a literal value, precede it with another backslash. Complex values can be composed by escaping characters that normally have some other processing meaning: 
PHRASE = 'Is (3 \* 4) \\ 2 = 6 \?'      to get 'Is (3 * 4) \ 2 = 6 ?'
Characters that have special meaning in content integration server queries must be escaped if they are to be taken literally. These characters include:
  • Asterisk (*)
  • Question mark (?)
  • Backslash (\)
  • Single quotation mark (')
Table 1. How special characters are escaped to retrieve specific results
Query criteria string Results Explanation
String LIKE * String, Strong, Stronger, Strange, Stranger, Str*ng, Str?ng, Str'ng, Str_nger, Str?*r, Str*n*, Str\anger, Str\onger, Str\?nger, Str\ange, Str\?nger, Str??ng, Str??nge, Str??ng*, Str?nger, Str\\?nger, Str\?\?ng, Str\?\?nger, Tom's Cabin All results are returned.
String LIKE ‘Str?n*’ String, Strong, Stronger, Strange, Stranger, Str*ng, Str?ng, Str'ng, Str_nger Replace single character for ?, and multiple characters for * at the end of the word.
String LIKE ‘Str?ng’ String, Strong, Str*ng, Str?ng, Str'ng Single character wildcard search.
String LIKE ‘Str?*r’ Stronger, Stranger, Str?*r, Str_nger Results strong and strange would not be returned because of the r at the end of the query string.
String LIKE ‘Str\*n*’ Str*ng, Str*nger, Str*n* The character combination \* indicates that the first asterisk is literal and not a wildcard character.
String = ‘Str*ng’ Str*ng Asterisk and question mark characters are meaningful only when the operator is LIKE.
String LIKE ‘Str\\?nger’ Str\anger, Str\onger, Str\?nger The backslash character in the query string is a literal, while the ? character is a single replacement wildcard character.
String LIKE ‘Str\\?n*’ Str\ange, Str\anger, Str\onger, Str\?n* The backslash character is literal because it is escaped in the query string.
String LIKE ‘Str\?\?ng*’ Str??ng, Str??nge, Str??ng* The values Str\?\?ng and Str\?\?nger are not found because the ? characters are both escaped with backslashes in the query string.
String LIKE ‘Tom’s Cabin’ InvalidQueryException Malformed query. The single quotation mark character within the word Tom's must be escaped in the query string.
String LIKE ‘Tom\’s Cabin’ Tom’s Cabin The string Tom\’s Cabin is not found because the backslash is used as an escape character in the query string. To find the literal string Tom\’s Cabin, both the backslash and the single quotation mark must be escaped in the query string: Tom\\\'s Cabin.

The single quotation marks and backslash characters must be escaped wherever they are used as literals in a content integration server query because these characters have a special meaning to IBM Content Integrator. If these characters are not escaped, an error might occur or the query might produce undesired results. For example, if you query for the string Tom's Cabin and you do not escape the single quotation mark, the query expression parser returns an exception and the query is not run. To search for Tom's Cabin, you would enter:

String = 'Tom\'s Cabin'

The string is converted by the connector into a form that is acceptable by the repository to produce results for the string Tom's Cabin. This might convert into Tom''s Cabin or Tom's Cabin depending on which repositories are searched. Client applications do not need to accommodate different repositories' accepted inputs because each corresponding connector handles the differences. Client applications can search seamless between the various repositories without regard to the repositories' special character or mechanism of escaping special characters.

Each repository has a repository profile that lists invalid character combinations. Invalid character combinations might be listed if the repository does not support escaping wildcard characters, if there are characters that are special to the repository that cannot be escaped, or if there are any other characters that are illegal to the repository. Never use these character combinations in a query on a repository with such restrictions.