com.netrics.likeit

Class NetricsSearchCfg

java.lang.Object

com.netrics.likeit.NetricsSearchCfg

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

NetricsDbSearchCfg

public class NetricsSearchCfg
extends java.lang.Object
implements java.io.Serializable

This class is used with the search methods of the NetricsServerInterface class to configure a query against one table. This includes the name of the table to be searched, giving a lock key for the table if desired, the query to be performed and any filtering predicate to be used. It also includes methods for building predicate expressions.

See Also:

NetricsServerInterface.search(com.netrics.likeit.NetricsSearchCfg, com.netrics.likeit.NetricsSearchOpts), Serialized Form

Constructor Summary

Constructors

Constructor and Description
NetricsSearchCfg(java.lang.String tblname)

Method Summary

Methods

Modifier and Type	Method and Description
void	addQuery(java.lang.String query, java.lang.String[] names) Deprecated. As of release 4.1.1. Use setNetricsQuery(NetricsQuery)
void	addQuery(java.lang.String query, java.lang.String[] names, double[] fieldWeights, double queryletWeight, int alignField, java.lang.String thesaurusName) Deprecated. As of release 4.1.1. Use setNetricsQuery(NetricsQuery)
static NetricsPredicate	CreateBoolOperand(boolean b) Create a predicate constant value of type boolean.
static NetricsPredicate	CreateDoubleOperand(double d) Create a predicate constant of type double.
static NetricsPredicate	CreateFieldNameOperand(java.lang.String fn) Create a predicate reference to a field using a field name.
static NetricsPredicate	CreateIntOperand(int i) Create a predicate constant value of type int.
static NetricsPredicate	CreatePredicate(NetricsPredicate predl, int op, NetricsPredicate predr) Create a predicate by combining two predicates that were previously created.
static NetricsPredicate	CreateStringOperand(java.lang.String s) Create a predicate constant of type String.
static NetricsPredicate	CreateUnaryPredicate(NetricsPredicate pred, int op) Create a predicate by combining a single predicate and an operation to be performed on the predicate.
void	makeDependentQuerylets(int[] multiqueryletIds) Deprecated. As of release 4.1.1. Use setNetricsQuery(NetricsQuery)
void	setLockKey(NetricsLock lock) Set the lock key for this search.
void	setNetricsQuery(NetricsQuery nq) Set the NetricsQuery object for this database.
void	SetSearchPredicate(NetricsPredicate pred) Set the search predicate for a given search.
void	SetSearchPredicate(java.lang.String expr) Set the search predicate from a string.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NetricsSearchCfg

public NetricsSearchCfg(java.lang.String tblname)

Method Detail

setNetricsQuery

public void setNetricsQuery(NetricsQuery nq)

Set the NetricsQuery object for this database.

Using the NetricsQuery object is the current preferred method for specifying searches using Netrics. The AddQuery and makeDependentQuerylets methods are thus being deprecated.

See Also:

NetricsQuery

setLockKey

public void setLockKey(NetricsLock lock)

Set the lock key for this search.

addQuery

public void addQuery(java.lang.String query,
            java.lang.String[] names)

Deprecated. As of release 4.1.1. Use setNetricsQuery(NetricsQuery)

Add a query to the NetricsSearchCfg object.

Queries are specified at the table level. That is, queries cannot span tables.

The AddQuery method works by passing a query string and an array of field names (which are field names in the table you are searching) against which to search. You can add as many query / field-name-array pairs as you like.

In the simple case, you can use the AddQuery method to restrict those fields against which you want to search (if some fields are non-searchable for instance).

Another good example is the case where you want to search each query against its associated field. That is, imagine you have a table of music with an artist field, album field, and song field. You might have an "advanced" search where you want to search an artist query against the artist field, album query against the album field, and so on.

In fact, you can specify any number of queries and any fields you want them to search against. You can even pass multiple NetricsSearchCfg objects to the search method, allowing you to search multiple tables at the same time.

Parameters:

query - The query that will be used to search the given field names.

names - The field names against which the query will be searched (null will search all fields in the table).

addQuery

public void addQuery(java.lang.String query,
            java.lang.String[] names,
            double[] fieldWeights,
            double queryletWeight,
            int alignField,
            java.lang.String thesaurusName)

Deprecated. As of release 4.1.1. Use setNetricsQuery(NetricsQuery)

Add a query using querylet field weights.

Parameters:

query - The query that will be used to search the given field names.

names - The field names against which the query will be searched.

fieldWeights - An array of doubles which weigh the importance of fields. Use a higher number to weigh a given field as more important. The doubles are one per field for the fields specified for this query (the lengths of the 2nd and 3rd parameters to this method should be the same). The valid range for the doubles is from 0.0 to 1.0 (In the Netrics Java Interface, UNLIKE OTHER NETRICS INTERFACES, field weights are normalized for you).

queryletWeight - Specifies the fraction of the entire record score that should come from this querylet. (A value of -1.0 will set each querylet to an equal weight.) If you set a queryletWeight for a query, you must set a queryletWeight for every query for the table.

alignField - The field number which this querylet will most likely be found in. This can be used as a hint to the search algorithm (field numbers start at 0).

thesaurusName - The name of a thesaurus to be used just for this querylet. (A null string will not use a thesaurus for the querylet.)

makeDependentQuerylets

public void makeDependentQuerylets(int[] multiqueryletIds)
                            throws NetricsException

Deprecated. As of release 4.1.1. Use setNetricsQuery(NetricsQuery)

It is recomended that you call this function if the same field is used in two or more querylets (i.e. a "First Name" querylet and a "Last Name" querylet against the same "Full Name" field). This function allows the user to specify which querylets are "dependent" on each other (i.e. only one or the other of the querylets can match a given stretch of text in the record). If this function is not used, the querylet dependencies will be automatically detected (by looking for overlapping fieldsets), but it is almost always better to use this function, even if the querylet dependencies are trivial.

Parameters:

multiqueryletIds - Any two querylets that are dependent are part of the same "multiquerylet." The multiqueryletIds parameter should be the same length as the number of querylets added to the NetricsSearchCfg. Each position in the array is the ID of the multiquerylet that querylet belongs to. In this way, if any two positions in the array have the same multiquerylet id, they will be added to the same multiquerylet and will thus be dependent querylets. It is an error to use multiquerylet ids less than 0 or greater than the number of querylets added to the NetricsSearchCfg object. For example, with querylets "First Name", "Last Name", and "Address", the array {0,0,1} would make the first two querylets dependent and the last querylet independent of the other two.

Throws:

NetricsException

CreateIntOperand

public static NetricsPredicate CreateIntOperand(int i)

Create a predicate constant value of type int.

See Also:

NetricsPredicate

CreateBoolOperand

public static NetricsPredicate CreateBoolOperand(boolean b)

Create a predicate constant value of type boolean.

See Also:

NetricsPredicate

CreateStringOperand

public static NetricsPredicate CreateStringOperand(java.lang.String s)

Create a predicate constant of type String.

See Also:

NetricsPredicate

CreateDoubleOperand

public static NetricsPredicate CreateDoubleOperand(double d)

Create a predicate constant of type double.

See Also:

NetricsPredicate

CreateFieldNameOperand

public static NetricsPredicate CreateFieldNameOperand(java.lang.String fn)

Create a predicate reference to a field using a field name.

See Also:

NetricsPredicate

CreatePredicate

public static NetricsPredicate CreatePredicate(NetricsPredicate predl,
                               int op,
                               NetricsPredicate predr)

Create a predicate by combining two predicates that were previously created.

The op parameter is applied between the two predicates. The possible op codes are listed in the table below.

Operator Id	Description
NetricsPredicate.EQUALS	The equality operator (==) - valid for string comparisons as well
NetricsPredicate.INSEN_EQUALS	The equality operator (==) - valid for case insensitive string comparisons as well
NetricsPredicate.LESSTHEN	The less than operator (<)
NetricsPredicate.INSEN_LESSTHEN	The case insensitive less than operator (<)
NetricsPredicate.LESSTHENOREQ	The less that or equal to operator (<=)
NetricsPredicate.INSEN_LESSTHENOREQ	The case insensitive less that or equal to operator (<=)
NetricsPredicate.GREATERTHAN	The greater than operator (>)
NetricsPredicate.INSEN_GREATERTHAN	The case insensitive greater than operator (>)
NetricsPredicate.GREATERTHANOREQ	The greater than or equal to operator (>=)
NetricsPredicate.INSEN_GREATERTHANOREQ	The case insensitive greater than or equal to operator (>=)
NetricsPredicate.PLUS	The addition operator (+)
NetricsPredicate.MINUS	The subtraction operator (-)
NetricsPredicate.TIMES	The multiplication operator (*)
NetricsPredicate.DIVIDEDBY	The division operator (/)
NetricsPredicate.TOTHE	The exponent operator (^)
NetricsPredicate.AND	The AND operator (&&)
NetricsPredicate.OR	The OR operator (||)
NetricsPredicate.ISIN	The substring operator - detects substring matches of the left operand in the right operand
NetricsPredicate.INSEN_ISIN	The substring operator - detects substring matches of the left operand in the right operand ignoring letter case
NetricsPredicate.TOKENIZE	The tokenize operator
NetricsPredicate.SUPERSET	The superset operator
NetricsPredicate.SUBSET	The subset operator

Remember, predicates can nested to an arbitrary depth.

See the NetricsPredicate object for information on predicates.

See Also:

NetricsPredicate

CreateUnaryPredicate

public static NetricsPredicate CreateUnaryPredicate(NetricsPredicate pred,
                                    int op)

Create a predicate by combining a single predicate and an operation to be performed on the predicate.

The possible op codes are listed in the table below.

Operator Id	Description
NetricsPredicate.MINUS	Negate - equivalent to multiplying by -1
NetricsPredicate.NOT	Not - logical negation (!)
NetricsPredicate.TOINT	To int type (cast)
NetricsPredicate.TODBL	To float type (cast)
NetricsPredicate.TODATE	To date type
NetricsPredicate.TODATEEU	To EU date type (European data format)
NetricsPredicate.TOKENIZE	Tokenize
NetricsPredicate.TOBLK	To block type
NetricsPredicate.TODATET	To date type, with time (default format yyyy/mm/dd HH:MM:SS)
NetricsPredicate.TODATEEUT	To EU date type, with time
NetricsPredicate.ABS	Absolute Value

Remember, predicates can nested to an arbitrary depth.

See the NetricsPredicate object for information on predicates.

See Also:

NetricsPredicate

SetSearchPredicate

public void SetSearchPredicate(NetricsPredicate pred)

Set the search predicate for a given search.

This is the predicate which must evaluate to true for any record returned by the search. In other words, the Netrics Server will return the "MatchesRequested" best records which evaluated to true for the given predicate. One one such filtering predicate can be defined for each table used in a search (i.e. one per NetricsSearchCfg object).

See the NetricsPredicate object for information on predicates.

See Also:

NetricsPredicate

SetSearchPredicate

public void SetSearchPredicate(java.lang.String expr)

Set the search predicate from a string.

In addition to building the search predicate piece by piece the entire predicate can be defined as a string using a SQL like syntax. The basic items in the syntax are:

?TRUE?, ?FALSE?	Boolean constant values are true and false enclosed in question marks. Letter case insensitive
123,0777,0x8FFF	Integer constant values. They follow the standard "C" and Java conventions for decimal, Octal and Hex integers.
123.45, 0.17e-10	Floating point values. They follow the standard "C" and Java conventions for fixed and scientific notation values.
"string"	string constants are enclosed in double quotes. The basic XML/HMTL encoding scheme is used to represent the double quote character (") itself and other special characters. The numeric conventions: &#ddd;, &#xhh; are recognized and the entity names: quot, amp, lt, gt and apos are recognized. No other entity names are recognized. Note that you must NOT insert an encoded NULL character into the string as this is a NULL terminated string value.
:"byte block"	A byte block is specified by preceding a quoted string value with a colon (:) character. The length of the block is computed automatically. All non-valid string characters must be encoded using the XML/HTML like encodings as defined for strings.
#2	Table fields specified by numeric position. An integer value preceded with the pound (#) character is used to represent the table field at the indicated column position. Like array indexes in Java and "C" these field numbers are zero based.
$"first name"	Table fields specified by field name. A quoted string value (see string description above) preceded by the dollar ($) sign. The string value is the field name.
[ :"block 1", :"block 2" ] [ :]	Block arrays. A comma separated list of blocks enclosed in square brackets ([]). To specify a Block array with zero entries use an open bracket followed by colon close bracket (:]) no space between the colon and close bracket.

Predicate expressions are defined in a typical manner. E.g.
INT $"age" > 21
specifies all records where the "age" field is greater than 21 (this assumes the age field is a text field, if the age field was of type integer then the conversion operator INT would not be needed). Parenthesis can be used to group operations into more complex expressions:
((INT $"age" + INT $"years experience") / 2) - 1 >= 21
Operators are left associative, that is:
2 + 3 + 12
is equivalent to:
(2 + 3) + 12

Operators have precedence similar to those in Java. So:
12 + 2 * 3
is the same as:
12 + (2 * 3)
Some key differences between the precedence of predicate operators and Java or "C" operators are:

• All unary operators have higher precedence (bind tighter) than binary operators.
• + has slightly higher precedence than - (minus), thus a - b + c is the same as a - (b + c) not (a - b) + c
• similarly multiply (*) has slightly higher precedence than divide (/)
• All comparison operators have the same precedence.

The binary operators listed from highest precedence to lowest are:

operators	description
**	raise to power
*	multiple
/	divide
+	addition for numbers, concatenation for strings
-	subtraction
=, ==, ~=, >, ~> >=, ~>=, <, ~<, <=, ~<=, SUBSET, SUPERSET, IN	Comparison operators, "=" and "==" are synonyms. Comparison operators prefixed with ~ perform letter case insensitive comparisons.
AND	Logical and joining operator, similar to the Java && operator
OR	Logical or joining operator, similar to the Java || operator

The unary operators are:

operator	description
+	arithmetic positive, this does nothing
-	arithmetic negation
NOT	logical inverse
UPPER	convert character string/byte block to upper case
LOWER	convert character string/byte block to lower case
INT	convert value to integer
DBL DOUBLE FLOAT	convert value to floating point. These are all synonyms for the same operation.
DATE	convert value to a date.
DATEEU EUDATE	convert value to a date. String and byte block format dates are assumed to be in European format. These are synonyms for the same operation
BLOCK	convert value to a byte block.
SPLIT TOKENIZE	split a string or block into a block array with each element of the array being a word from the string.
ABS	return the Absolute Value of an integer or double value.

The names of operators are letter case insensitive. So ABS, Abs and abs are all names for the same absolute value operator. For more information on these operations see NetricsPredicate.

The final example from NetricsPredicate as a string predicate would be:

NetricsSearchCfg tblcfg = new NetricsSearchCfg("tbl");
tblcfg.SetSearchPredicate("$\"Company\" == \"Pepsi\" or $\"Company\" == \"Coke\"");

See Also:

NetricsPredicate