How to Implement Full-Text Search in SQL Server

Full-text search in SQL Server allows for efficient searching of text data stored in tables. Unlike the traditional LIKE operator, full-text search enables powerful linguistic-based searches, ranking results by relevance and supporting advanced features like inflectional search and proximity queries. In this guide, we will walk through the steps to implement full-text search in SQL Server.

Before using full-text search, ensure that your SQL Server instance supports and has full-text search enabled. You can check this by running:

SELECT SERVERPROPERTY('IsFullTextInstalled') AS FullTextInstalled;

If the result is 1, full-text search is installed; otherwise, you may need to install it.

Step 2: Create a Full-Text Catalog

A full-text catalog is a container for full-text indexes. To create one, use:

CREATE FULLTEXT CATALOG MyFullTextCatalog AS DEFAULT;

Step 3: Create a Full-Text Index

A full-text index is required on the columns you want to search. First, make sure your table has a unique index:

CREATE UNIQUE INDEX UI_MyTable ON MyTable(Id);

Then, create a full-text index:

CREATE FULLTEXT INDEX ON MyTable(
    MyTextColumn LANGUAGE 1033
)
KEY INDEX UI_MyTable
ON MyFullTextCatalog;

The LANGUAGE 1033 specifies English. You can change this according to the language used in your data.

Step 4: Perform Full-Text Searches

Once the index is created, you can perform full-text searches using CONTAINS and FREETEXT.

Using CONTAINS

CONTAINS allows you to search for exact words or phrases:

SELECT * FROM MyTable
WHERE CONTAINS(MyTextColumn, '"search term"');

You can also use logical operators like AND, OR, and NEAR:

SELECT * FROM MyTable
WHERE CONTAINS(MyTextColumn, '"SQL Server" NEAR "Index"');

Using FREETEXT

FREETEXT allows for a broader, natural language search:

SELECT * FROM MyTable
WHERE FREETEXT(MyTextColumn, 'search term');
  • Populate the Full-Text Index: Full-text indexes are updated automatically, but you can manually trigger an update:

    ALTER FULLTEXT INDEX ON MyTable START FULL POPULATION;
    
  • Monitor Full-Text Indexing: Check the status of your full-text population with:

    SELECT * FROM sys.fulltext_indexes;
    
  • Remove a Full-Text Index: If needed, drop the index using:

    DROP FULLTEXT INDEX ON MyTable;
    

Conclusion

Full-text search in SQL Server is a powerful tool for handling complex text-based queries. By enabling full-text search, creating an index, and using CONTAINS or FREETEXT queries, you can significantly improve search performance and relevance in your applications. With proper indexing and management, full-text search can be a game-changer for handling large text-based datasets.

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Related

When working with SQL Server, you may often need to count the number of unique values in a specific column. This is useful for analyzing data, detecting duplicates, and understanding dataset distributions.

Using COUNT(DISTINCT column_name)

To count the number of unique values in a column, SQL Server provides the COUNT(DISTINCT column_name) function. Here’s a simple example:

SELECT COUNT(DISTINCT column_name) AS distinct_count
FROM table_name;

This query will return the number of unique values in column_name.

Counting Distinct Values Across Multiple Columns

If you need to count distinct combinations of multiple columns, you can use a subquery:

SELECT COUNT(*) AS distinct_count
FROM (SELECT DISTINCT column1, column2 FROM table_name) AS subquery;

This approach ensures that only unique pairs of column1 and column2 are counted.

Why Use COUNT DISTINCT?

  • Helps in identifying unique entries in a dataset.
  • Useful for reporting and analytics.
  • Efficient way to check for duplicates.

By leveraging COUNT(DISTINCT column_name), you can efficiently analyze your database and extract meaningful insights. Happy querying!

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Closing a SqlDataReader correctly prevents memory leaks, connection issues, and unclosed resources. Here’s the best way to do it.

Use 'using' to Auto-Close

Using using statements ensures SqlDataReader and SqlConnection are closed even if an exception occurs.

Example

using (SqlConnection conn = new SqlConnection(connectionString))
{
    conn.Open();
    using (SqlCommand cmd = new SqlCommand("SELECT * FROM Users", conn))
    using (SqlDataReader reader = cmd.ExecuteReader())
    {
        while (reader.Read())
        {
            Console.WriteLine(reader["Username"]);
        }
    } // ✅ Auto-closes reader here
} // ✅ Auto-closes connection here

This approach auto-closes resources when done and it is cleaner and less error-prone than manual closing.

⚡ Alternative: Manually Close in finally Block

If you need explicit control, you can manually close it inside a finally block.

SqlDataReader? reader = null;
try
{
    using SqlConnection conn = new SqlConnection(connectionString);
    conn.Open();
    using SqlCommand cmd = new SqlCommand("SELECT * FROM Users", conn);
    reader = cmd.ExecuteReader();

    while (reader.Read())
    {
        Console.WriteLine(reader["Username"]);
    }
}
finally
{
    reader?.Close();  // ✅ Closes reader if it was opened
}

This is slightly more error prone if you forget to add a finally block. But might make sense when you need to handle the reader separately from the command or connection.

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Slow initial load times can drive users away from your React application. One powerful technique to improve performance is lazy loading - loading components only when they're needed.

Let's explore how to implement this in React.

The Problem with Eager Loading

By default, React bundles all your components together, forcing users to download everything upfront. This makes navigation much quicker and more streamlined once this initial download is complete.

However, depending on the size of your application, it could also create a long initial load time.

import HeavyComponent from './HeavyComponent';
import AnotherHeavyComponent from './AnotherHeavyComponent';

function App() {
  return (
    <div>
      {/* These components load even if user never sees them */}
      <HeavyComponent />
      <AnotherHeavyComponent />
    </div>
  );
}

React.lazy() to the Rescue

React.lazy() lets you defer loading components until they're actually needed:

import React, { lazy, Suspense } from 'react';

// Components are now loaded only when rendered
const HeavyComponent = lazy(() => import('./HeavyComponent'));
const AnotherHeavyComponent = lazy(() => import('./AnotherHeavyComponent'));

function App() {
  return (
    <div>
      <Suspense fallback={<div>Loading...</div>}>
        <HeavyComponent />
        <AnotherHeavyComponent />
      </Suspense>
    </div>
  );
}

Route-Based Lazy Loading

Combine with React Router for even better performance:

import React, { lazy, Suspense } from 'react';
import { BrowserRouter, Routes, Route } from 'react-router-dom';

const Home = lazy(() => import('./pages/Home'));
const Dashboard = lazy(() => import('./pages/Dashboard'));
const Settings = lazy(() => import('./pages/Settings'));

function App() {
  return (
    <BrowserRouter>
      <Suspense fallback={<div>Loading...</div>}>
        <Routes>
          <Route path="/" element={<Home />} />
          <Route path="/dashboard" element={<Dashboard />} />
          <Route path="/settings" element={<Settings />} />
        </Routes>
      </Suspense>
    </BrowserRouter>
  );
}

Implement these techniques in your React application today and watch your load times improve dramatically!

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