Update README.md

search-input-query-parser/README.md

@@ -35,3 +35,103 @@ if (result.type === 'SEARCH_QUERY') {
   console.log(result.errors);
 }
 ```
+## SQL Conversion
+
+The parser can convert search queries into SQL WHERE clauses using three different search strategies:
+
+1. ILIKE - Case-insensitive pattern matching
+2. tsvector - PostgreSQL full-text search
+3. ParadeDB - BM25-based full-text search
+
+### Basic Usage
+
+```typescript
+import {
+  searchStringToIlikeSql,
+  searchStringToTsVectorSql,
+  searchStringToParadeDBSql,
+  type FieldSchema
+} from 'search-input-query-parser';
+
+// Define searchable columns and schemas
+const searchableColumns = ['title', 'description'];
+const schemas: FieldSchema[] = [
+  { name: 'title', type: 'string' },
+  { name: 'price', type: 'number' },
+  { name: 'date', type: 'date' }
+];
+
+// Convert a search query to SQL
+const query = 'winter boots AND price:>100';
+
+// Using ILIKE (case-insensitive pattern matching)
+const ilikeResult = searchStringToIlikeSql(query, searchableColumns, schemas);
+// Result:
+// {
+//   text: "((lower(title) LIKE lower($1) OR lower(description) LIKE lower($1)) AND price > $2)",
+//   values: ["%winter boots%", 100]
+// }
+
+// Using tsvector (PostgreSQL full-text search)
+const tsvectorResult = searchStringToTsVectorSql(query, searchableColumns, schemas);
+// Result:
+// {
+//   text: "((to_tsvector('english', title) || to_tsvector('english', description)) @@ plainto_tsquery('english', $1) AND price > $2)",
+//   values: ["winter boots", 100]
+// }
+
+// Using ParadeDB (BM25 search)
+const paradedbResult = searchStringToParadeDBSql(query, searchableColumns, schemas);
+// Result:
+// {
+//   text: "((title @@@ $1 OR description @@@ $1) AND price @@@ '>' || $2)",
+//   values: ['"winter boots"', 100]
+// }
+```
+
+### Search Types Comparison
+
+| Feature | ILIKE | tsvector | ParadeDB |
+|---------|-------|----------|----------|
+| Case Sensitivity | Case-insensitive | Case-insensitive | Case-sensitive |
+| Pattern Matching | Simple wildcards | Language-aware tokens | BM25 ranking |
+| Performance | Slower on large datasets | Fast with proper indexes | Fast with proper indexes |
+| Setup Required | None | PostgreSQL extension | ParadeDB extension |
+| Best For | Simple searches, small datasets | Advanced text search | Relevance-based search |
+
+### Configuration Options
+
+```typescript
+// Common options for all search types
+interface SearchQueryOptions {
+  language?: string;  // Language for text analysis (default: 'english')
+}
+
+// Example with options
+const result = searchStringToTsVectorSql(
+  query,
+  searchableColumns,
+  schemas,
+  {
+    language: 'spanish'
+  }
+);
+```
+
+### Using with Raw SQL
+
+The converters return objects with `text` (the WHERE clause) and `values` (the parameter values):
+
+```typescript
+import { searchStringToIlikeSql } from 'search-input-query-parser';
+
+const base = 'SELECT * FROM products';
+const { text, values } = searchStringToIlikeSql(query, searchableColumns, schemas);
+const fullQuery = `${base} WHERE ${text}`;
+
+// Using with node-postgres
+const result = await client.query(fullQuery, values);
+
+// Using with Prisma
+const result = await prisma.$queryRaw`${Prisma.raw(base)} WHERE ${Prisma.raw(text)}`;
+```