Module 8: Querying Full-Text Indexes

Overview

Introduction to Microsoft Search Service

Microsoft Search Service Components

Getting Information About Full-Text Indexes

Writing Full-Text Queries

Introduction to Microsoft Search Service

Provides Text-based Searches in SQL Server

Complex searches on unstructured text data for words and phrases

More powerful than LIKE operator and wildcards

Available in Other Microsoft Products

Indexing Service, Exchange 2000, Commerce Server

Microsoft Search Service Components

Search Service Structures

Full-text indexKeeps track of significant words used in a tableRequires unique key column or primary key

Full-text catalogIs a collection of full-text indexes

Microsoft Search Service Functions

Indexing Querying

Getting Information About Full-Text Indexes

Using System Stored Procedures sp_help_fulltext_catalogs sp_help_fulltext_tables sp_help_fulltext_columns

Using Transact-SQL Functions

Use Transact-SQL functions to obtain information about full-text properties

USE northwindSELECT DATABASEPROPERTY('Northwind','IsFullTextEnabled')GO

USE northwindSELECT DATABASEPROPERTY('Northwind','IsFullTextEnabled')GO

Writing Full-Text Queries

CONTAINS Predicate

FREETEXT Predicate

CONTAINSTABLE and FREETEXTTABLE Functions

Using Full-Text Keywords

CONTAINS Predicate

Inflectional Form of a Specific Word

Word or Phrase Beginning with Specific Text

Word or Phrase near Another Word or Phrase

One or More Specific Words and Phrases

Words or Phrases with Weighted Values

SELECT plant_id, common_name, price FROM plants WHERE CONTAINS( *, ' "English Thyme" ' )GO

SELECT plant_id, common_name, price FROM plants WHERE CONTAINS( *, ' "English Thyme" ' )GO

Example 1Example 1

FREETEXT Predicate

Searches on Words, Phrases, and Sentences Extracted from Initial Query

Less Precise Than the CONTAINS Predicate

SELECT * FROM news_table WHERE FREETEXT( description, '"The Fulton County Grand Jury said Friday an investigation of Atlanta‘s recent primary election produced no evidence that any irregularities took place."')GO

SELECT * FROM news_table WHERE FREETEXT( description, '"The Fulton County Grand Jury said Friday an investigation of Atlanta‘s recent primary election produced no evidence that any irregularities took place."')GO

CONTAINSTABLE and FREETEXTTABLE Functions

Using CONTAINSTABLE and FREETEXTTABLE Return a table Return column that contains full-text key values top_n_by_rank argument

Choosing Which Search Condition or Function to Use

Use the CONTAINS and FREETEXT predicates in any search condition

Use the CONTAINSTABLE and FREETEXTTABLE functions in the FROM clause

Using Full-Text Keywords

USE pubsSELECT T.title, P.pub_name FROM publishers AS P INNER JOIN titles AS T ON P.pub_id = I.pub_id WHERE P.pub_id = (SELECT pub_id FROM pub_info WHERE CONTAINS

(pr_info, ' moonbeam AND ontario AND "flying saucer" '))GO

USE pubsSELECT T.title, P.pub_name FROM publishers AS P INNER JOIN titles AS T ON P.pub_id = I.pub_id WHERE P.pub_id = (SELECT pub_id FROM pub_info WHERE CONTAINS

(pr_info, ' moonbeam AND ontario AND "flying saucer" '))GO

USE northwindSELECT Description FROM Categories WHERE CategoryName <> 'Seafood‘ AND CONTAINS(Description, ' sauces AND seasonings ')GO

USE northwindSELECT Description FROM Categories WHERE CategoryName <> 'Seafood‘ AND CONTAINS(Description, ' sauces AND seasonings ')GO

CONTAINS and FREETEXT PredicatesCONTAINS and FREETEXT Predicates

CONTAINS Within a SubqueryCONTAINS Within a Subquery

Use Full-Text Indexes on CHAR, NCHAR, VARCHAR, NVARCHAR, TEXT, NTEXT and IMAGE Data TypesUse Full-Text Indexes on CHAR, NCHAR, VARCHAR, NVARCHAR, TEXT, NTEXT and IMAGE Data Types

Use the Full-Text Index and Catalog Properties for TroubleshootingUse the Full-Text Index and Catalog Properties for Troubleshooting

Use the top_n_by_rank Argument to Restrict Result Set SizeUse the top_n_by_rank Argument to Restrict Result Set Size

Recommended Practices

Lab A: Querying Full-Text Indexes

Review

Introduction to Microsoft Search Service

Microsoft Search Service Components

Getting Information About Full-Text Indexes

Writing Full-Text Queries