Search Help

English Search Help:

• Using an asterisk symbol (*) at the end of your search word can increase the possibility of returning more search results. For example, if you use pen to do the search, it will return all items that have pen word in the item description; if you use pencil to do the search, it will return all items that have pencil in item description; if you use pen* to do the search, it will return all items that have pen, or pencil.

           For more accurate search, you can use logical operators such as and, or, not in your search, and use parenthesises ( ) to group your search words or search terms, or to have priority. The logical operator and is optional and can be omitted. For example:

• light bulb Searches for items containing inflectional forms of the words light and bulb.
  
• light and bulb Searches for items containing inflectional forms of the words light and bulb. The keyword and is optional and can be omitted.
  
• circuit or breaker Searches for items containing infectional forms of the words circuit or breaker.
• lamp not bulb Searches for items containing inflectional forms of the word lamp but not the word bulb
• "light bulb" enclose your phrase in quotation marks to make the search by the whole phrase in its entirety
• circuit* Searches for words that begin with the prefix circuit
• (lamp red) or (bulb not blue) Searches for items containing inflectional forms of the words lamp and red, or bulb but not containing the word blue
• orange (pen or pencil) Searches for items containing inflectional forms of the words orange pen, or orange pencil

Note: The search technique is similar to Google's search. User's search input is scanned and parsed by a homegrown compiler into an expression tree, and then translated into a WHERE clause of a Transact-SQL SELECT statement to perform SQL Server full-text search on full-text indexed columns containing character-based data type. However due to the limitation of the contains() function from Microsoft, logical operator not can not be used after or, neither can it be used before a standalone search term, it can only be used after logical operator and (which can be omitted).
So the following will not work: 1) jacket or not pants
                                                   2) not pants (as a standalone search term)
But the following works: 1) jacket and not pants
                                         2) jacket not pants

The following Grammar is implemented by the homegrown compiler:

PrimaryExpression ::= TermExpr | PhraseExpr | ParenthesizedExpression
AndExpression ::= PrimaryExpression | AndExpression AndOperator PrimaryExpression //leftRecursive: need to be converted to PrimaryExpr {AndOperator PrimaryExpr}*
OrExpression ::= AndExpression | OrExpression OrOperator AndExpression //leftRecursive: need to be converted to AndExpr {OrOperator AndExpr}*
ParenthesizedExpression ::= (OrExpression)
TermExpr ::= TermToken
PhraseExpr :: = PhraseToken
AndOperator ::= emptyString (or blank space) between TermTokens, PhraseToken, and ParenthesizedExpression | AND | AND NOT | NOT | 与 | AND 非 | 与 NOT | 与 非 | 非
OrOperator ::= OR | 或
Note: AND, OR, NOT, (与, 或, 非) must be separated with blank space from a search term, otherwise they will be considered as a part of the search term