Add named parameter support for SQL queries

New Feature: Named SQL Parameters - Supports both positional (?) and named (:name) parameters - Named parameters are order-independent and more readable - Syntax: sqlite_param :param_name $variable Implementation: - Updated sqlite_param directive to accept 1 or 2 arguments - ModuleConfig.query_params now stores (name, variable) pairs - execute_query() detects named vs positional parameters - Extracted row_to_map closure to avoid type conflicts - Named params use rusqlite named parameter binding Examples (Port 8082): - Book detail: WHERE id = :book_id - Genre filter: WHERE genre = :genre_name - Year range: WHERE year >= :min_year AND year <= :max_year - Title search: WHERE title LIKE '%' || :search_term || '%' - Rating filter: WHERE rating >= :min_rating Benefits of Named Parameters: - Order-independent: params can be in any order in config - Self-documenting: :book_id is clearer than first ? - Maintainable: can add/remove params without reordering - Recommended for all but simplest queries Configuration: - conf/book_named_params.conf: Complete named params example - start_named_params.sh: Quick start script for port 8082 Documentation: - Added named vs positional comparison in README_PARAMETERS.md - Updated README.md with named parameter examples - Documented both syntaxes in directive reference All examples tested and working with both parameter styles.
2025-11-15 15:20:40 -08:00
parent 775467da51
commit e016c2421b
7 changed files with 531 additions and 40 deletions
--- a/README.md
+++ b/README.md
@ -48,17 +48,29 @@ A full-featured catalog with category browsing, global templates, and responsive

 **See:** `conf/book_catalog.conf` and `README_BOOK_CATALOG.md`

-### Example 2: Parameterized Queries (Port 8081)
+### Example 2: Positional Parameters (Port 8081)

-Demonstrates dynamic SQL queries with nginx variables.
+Demonstrates dynamic SQL queries with positional parameters.

 **Features:**
- Book detail pages by ID
- Genre filtering with query parameters
- Year range searches with multiple parameters
- Safe prepared statement parameter binding
+- Query parameters with `?` placeholders
+- Multiple positional parameters
+- Safe prepared statement binding

-**See:** `conf/book_detail.conf` and `README_PARAMETERS.md`
+**See:** `conf/book_detail.conf`
+
+### Example 3: Named Parameters (Port 8082) - Recommended
+
+Demonstrates named SQL parameters for better readability.
+
+**Features:**
+- Named parameters with `:name` syntax
+- Order-independent parameter binding
+- Title search with LIKE operator
+- Rating filtering
+- More maintainable configuration
+
+**See:** `conf/book_named_params.conf` and `README_PARAMETERS.md`

 ## Configuration Directives

@ -85,9 +97,14 @@ Specify the Handlebars template file (relative to location path).
 ### `sqlite_param`
 Add a parameter to the SQL query (can be used multiple times).

-**Syntax:** `sqlite_param $variable_or_value;`  
+**Syntax:**  
+- Positional: `sqlite_param $variable_or_value;`  
+- Named: `sqlite_param :param_name $variable_or_value;`
+
 **Context:** `location`  
-**Notes:** Order matches `?` placeholders in query
+**Notes:**  
+- Positional parameters match `?` placeholders in order
+- Named parameters match `:name` placeholders by name (recommended)

 ### `sqlite_global_templates`
 Set a directory for global template files (partials, layouts).
@ -112,13 +129,22 @@ http {
            sqlite_template "list.hbs";
        }
        
-        # Parameterized query
+        # Parameterized query with named parameter (recommended)
        location = /book {
            sqlite_db "catalog.db";
-            sqlite_query "SELECT * FROM books WHERE id = ?";
-            sqlite_param $arg_id;
+            sqlite_query "SELECT * FROM books WHERE id = :book_id";
+            sqlite_param :book_id $arg_id;
            sqlite_template "detail.hbs";
        }
+        
+        # Positional parameters also supported
+        location = /search {
+            sqlite_db "catalog.db";
+            sqlite_query "SELECT * FROM books WHERE year >= ? AND year <= ?";
+            sqlite_param $arg_min;  # First ?
+            sqlite_param $arg_max;  # Second ?
+            sqlite_template "list.hbs";
+        }
    }
 }
 ```
--- a/README_PARAMETERS.md
+++ b/README_PARAMETERS.md
@ -8,13 +8,49 @@ The sqlite-serve module supports parameterized SQL queries using nginx variables

 Add parameters to SQL queries. Can be used multiple times to add multiple parameters.

-**Syntax:** `sqlite_param variable_or_value;`  
+**Syntax:**  
+- Positional: `sqlite_param variable_or_value;`  
+- Named: `sqlite_param :param_name variable_or_value;`  
+
 **Context:** `location`  
-**Multiple:** Yes (order matches `?` placeholders in query)
+**Multiple:** Yes  
+
+**Note:** Positional parameters match `?` placeholders in order. Named parameters match `:name` placeholders by name.

 ## Usage

-### Query Parameters (Most Common)
+### Named Parameters (Recommended)
+
+Named parameters provide better readability and don't depend on order:
+
+```nginx
+location = /book {
+    sqlite_db "book_catalog.db";
+    sqlite_query "SELECT * FROM books WHERE id = :book_id";
+    sqlite_param :book_id $arg_id;     # Named parameter
+    sqlite_template "detail.hbs";
+}
+```
+
+**Request:** `http://localhost/book?id=5`  
+**SQL Executed:** `SELECT * FROM books WHERE id = '5'`
+
+### Multiple Named Parameters
+
+```nginx
+location = /years {
+    sqlite_db "book_catalog.db";
+    sqlite_query "SELECT * FROM books WHERE year >= :min AND year <= :max";
+    sqlite_param :min $arg_min;        # Order doesn't matter
+    sqlite_param :max $arg_max;        # with named params
+    sqlite_template "list.hbs";
+}
+```
+
+**Request:** `http://localhost/years?min=2015&max=2024`  
+**SQL Executed:** `SELECT * FROM books WHERE year >= '2015' AND year <= '2024'`
+
+### Query Parameters (Positional)

 Use nginx's built-in `$arg_*` variables to access query parameters:

@ -267,10 +303,46 @@ Run it with:
 - All SQL placeholders must be `?` (positional parameters)
 - Parameters match placeholders in order of `sqlite_param` directives

+## Named vs Positional Parameters
+
+### Named Parameters (`:name` syntax) - Recommended ✓
+
+**Advantages:**
+- Order-independent: Can rearrange `sqlite_param` directives without breaking queries
+- Self-documenting: Parameter names explain their purpose
+- Safer for maintenance: Adding/removing parameters less error-prone
+- Better for complex queries with many parameters
+
+**Example:**
+```nginx
+sqlite_query "SELECT * FROM books WHERE author = :author AND year > :year";
+sqlite_param :year $arg_year;      # Order doesn't matter!
+sqlite_param :author $arg_author;
+```
+
+### Positional Parameters (`?` syntax)
+
+**Advantages:**
+- Slightly more compact configuration
+- Works well for simple 1-2 parameter queries
+
+**Disadvantages:**
+- Order-dependent: Parameters must match `?` placeholders exactly
+- Less readable with many parameters
+- Error-prone when modifying queries
+
+**Example:**
+```nginx
+sqlite_query "SELECT * FROM books WHERE author = ? AND year > ?";
+sqlite_param $arg_author;  # Must be first!
+sqlite_param $arg_year;    # Must be second!
+```
+
+**Recommendation:** Use named parameters (`:name`) for all but the simplest queries.
+
 ## Limitations

- Only supports `?` positional parameters (not named parameters like `:name`)
- Parameters must be provided in the exact order they appear in the query
 - All parameter values are treated as strings (SQLite performs type coercion)
 - Complex SQL values (arrays, JSON) should be constructed in the query itself
+- Cannot mix positional and named parameters in the same query

--- a/conf/book_named_params.conf
+++ b/conf/book_named_params.conf
@ -0,0 +1,74 @@
+# Book Catalog with Named Parameters
+# Demonstrates using named SQL parameters for better readability
+
+load_module target/debug/libsqlite_serve.dylib;
+
+worker_processes 1;
+events {}
+
+error_log logs/error.log debug;
+
+http {
+    sqlite_global_templates "server_root/global_templates";
+
+    server {
+        listen 8082;
+        
+        root "server_root";
+
+        # Book detail with named parameter
+        location = /book {
+            add_header "Content-Type" "text/html; charset=utf-8";
+            sqlite_db "book_catalog.db";
+            sqlite_query "SELECT * FROM books WHERE id = :book_id";
+            sqlite_param :book_id $arg_id;
+            sqlite_template "detail.hbs";
+        }
+
+        # Genre filter with named parameter
+        location = /genre {
+            add_header "Content-Type" "text/html; charset=utf-8";
+            sqlite_db "book_catalog.db";
+            sqlite_query "SELECT * FROM books WHERE genre = :genre_name ORDER BY rating DESC";
+            sqlite_param :genre_name $arg_genre;
+            sqlite_template "genre.hbs";
+        }
+
+        # Year range with named parameters
+        location = /years {
+            add_header "Content-Type" "text/html; charset=utf-8";
+            sqlite_db "book_catalog.db";
+            sqlite_query "SELECT * FROM books WHERE year >= :min_year AND year <= :max_year ORDER BY year DESC, title";
+            sqlite_param :min_year $arg_min;
+            sqlite_param :max_year $arg_max;
+            sqlite_template "list.hbs";
+        }
+
+        # Search by title with named parameter
+        location = /search {
+            add_header "Content-Type" "text/html; charset=utf-8";
+            sqlite_db "book_catalog.db";
+            sqlite_query "SELECT * FROM books WHERE title LIKE '%' || :search_term || '%' ORDER BY rating DESC, title";
+            sqlite_param :search_term $arg_q;
+            sqlite_template "list.hbs";
+        }
+        
+        # Filter by rating with named parameter
+        location = /top-rated {
+            add_header "Content-Type" "text/html; charset=utf-8";
+            sqlite_db "book_catalog.db";
+            sqlite_query "SELECT * FROM books WHERE rating >= :min_rating ORDER BY rating DESC, title";
+            sqlite_param :min_rating $arg_rating;
+            sqlite_template "list.hbs";
+        }
+
+        # Fallback to all books
+        location / {
+            add_header "Content-Type" "text/html; charset=utf-8";
+            sqlite_db "book_catalog.db";
+            sqlite_query "SELECT * FROM books ORDER BY rating DESC, title";
+            sqlite_template "list.hbs";
+        }
+    }
+}
+
--- a/server_root/search/list.hbs
+++ b/server_root/search/list.hbs
@ -0,0 +1,122 @@
+{{> header}}
+
+<style>
+    .book-grid {
+        display: grid;
+        grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
+        gap: 1.5rem;
+        margin-top: 1.5rem;
+    }
+    .book-card {
+        background: #fff;
+        border: 2px solid #e9ecef;
+        border-radius: 8px;
+        padding: 1.5rem;
+        transition: all 0.3s;
+    }
+    .book-card:hover {
+        transform: translateY(-4px);
+        box-shadow: 0 8px 16px rgba(102, 126, 234, 0.2);
+        border-color: #667eea;
+    }
+    .book-header {
+        display: flex;
+        justify-content: space-between;
+        align-items: start;
+        margin-bottom: 0.5rem;
+    }
+    .book-title {
+        color: #2d3748;
+        font-size: 1.25rem;
+        margin-bottom: 0.25rem;
+        flex: 1;
+    }
+    .book-rating {
+        background: #fef3c7;
+        color: #92400e;
+        padding: 0.25rem 0.75rem;
+        border-radius: 20px;
+        font-weight: bold;
+        font-size: 0.9rem;
+        white-space: nowrap;
+        margin-left: 0.5rem;
+    }
+    .book-author {
+        color: #667eea;
+        font-weight: 500;
+        margin-bottom: 0.75rem;
+    }
+    .book-description {
+        color: #4a5568;
+        margin-bottom: 1rem;
+        line-height: 1.5;
+    }
+    .book-details {
+        display: flex;
+        flex-wrap: wrap;
+        gap: 0.5rem;
+        font-size: 0.875rem;
+    }
+    .book-genre {
+        background: #667eea;
+        color: white;
+        padding: 0.25rem 0.75rem;
+        border-radius: 4px;
+        font-weight: 500;
+    }
+    .book-year {
+        background: #e9ecef;
+        color: #495057;
+        padding: 0.25rem 0.75rem;
+        border-radius: 4px;
+    }
+    .book-isbn {
+        color: #6c757d;
+        font-family: monospace;
+        font-size: 0.8rem;
+    }
+    .stats {
+        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        color: white;
+        padding: 1.5rem;
+        border-radius: 8px;
+        margin-bottom: 2rem;
+        display: flex;
+        justify-content: space-around;
+        text-align: center;
+    }
+    .stat-item h2 {
+        font-size: 2.5rem;
+        margin-bottom: 0.25rem;
+    }
+    .stat-item p {
+        opacity: 0.9;
+        font-size: 0.9rem;
+    }
+</style>
+
+<div class="stats">
+    <div class="stat-item">
+        <h2>📚</h2>
+        <p>Book Collection</p>
+    </div>
+    <div class="stat-item">
+        <h2>⭐</h2>
+        <p>Top Rated</p>
+    </div>
+    <div class="stat-item">
+        <h2>🔍</h2>
+        <p>Browse All</p>
+    </div>
+</div>
+
+<h2 style="color: #2d3748; margin-bottom: 1rem;">All Books in Collection</h2>
+
+<div class="book-grid">
+    {{#each results}}
+        {{> book_card}}
+    {{/each}}
+</div>
+
+{{> footer}}
+
--- a/server_root/top-rated/list.hbs
+++ b/server_root/top-rated/list.hbs
@ -0,0 +1,122 @@
+{{> header}}
+
+<style>
+    .book-grid {
+        display: grid;
+        grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
+        gap: 1.5rem;
+        margin-top: 1.5rem;
+    }
+    .book-card {
+        background: #fff;
+        border: 2px solid #e9ecef;
+        border-radius: 8px;
+        padding: 1.5rem;
+        transition: all 0.3s;
+    }
+    .book-card:hover {
+        transform: translateY(-4px);
+        box-shadow: 0 8px 16px rgba(102, 126, 234, 0.2);
+        border-color: #667eea;
+    }
+    .book-header {
+        display: flex;
+        justify-content: space-between;
+        align-items: start;
+        margin-bottom: 0.5rem;
+    }
+    .book-title {
+        color: #2d3748;
+        font-size: 1.25rem;
+        margin-bottom: 0.25rem;
+        flex: 1;
+    }
+    .book-rating {
+        background: #fef3c7;
+        color: #92400e;
+        padding: 0.25rem 0.75rem;
+        border-radius: 20px;
+        font-weight: bold;
+        font-size: 0.9rem;
+        white-space: nowrap;
+        margin-left: 0.5rem;
+    }
+    .book-author {
+        color: #667eea;
+        font-weight: 500;
+        margin-bottom: 0.75rem;
+    }
+    .book-description {
+        color: #4a5568;
+        margin-bottom: 1rem;
+        line-height: 1.5;
+    }
+    .book-details {
+        display: flex;
+        flex-wrap: wrap;
+        gap: 0.5rem;
+        font-size: 0.875rem;
+    }
+    .book-genre {
+        background: #667eea;
+        color: white;
+        padding: 0.25rem 0.75rem;
+        border-radius: 4px;
+        font-weight: 500;
+    }
+    .book-year {
+        background: #e9ecef;
+        color: #495057;
+        padding: 0.25rem 0.75rem;
+        border-radius: 4px;
+    }
+    .book-isbn {
+        color: #6c757d;
+        font-family: monospace;
+        font-size: 0.8rem;
+    }
+    .stats {
+        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+        color: white;
+        padding: 1.5rem;
+        border-radius: 8px;
+        margin-bottom: 2rem;
+        display: flex;
+        justify-content: space-around;
+        text-align: center;
+    }
+    .stat-item h2 {
+        font-size: 2.5rem;
+        margin-bottom: 0.25rem;
+    }
+    .stat-item p {
+        opacity: 0.9;
+        font-size: 0.9rem;
+    }
+</style>
+
+<div class="stats">
+    <div class="stat-item">
+        <h2>📚</h2>
+        <p>Book Collection</p>
+    </div>
+    <div class="stat-item">
+        <h2>⭐</h2>
+        <p>Top Rated</p>
+    </div>
+    <div class="stat-item">
+        <h2>🔍</h2>
+        <p>Browse All</p>
+    </div>
+</div>
+
+<h2 style="color: #2d3748; margin-bottom: 1rem;">All Books in Collection</h2>
+
+<div class="book-grid">
+    {{#each results}}
+        {{> book_card}}
+    {{/each}}
+</div>
+
+{{> footer}}
+
--- a/src/lib.rs
+++ b/src/lib.rs
@ -1,7 +1,7 @@
 use handlebars::Handlebars;
 use ngx::core::Buffer;
 use ngx::ffi::{
-    ngx_hash_key, ngx_http_get_variable, NGX_CONF_TAKE1, NGX_HTTP_LOC_CONF,
+    ngx_hash_key, ngx_http_get_variable, NGX_CONF_TAKE1, NGX_CONF_TAKE2, NGX_HTTP_LOC_CONF,
    NGX_HTTP_MAIN_CONF, NGX_HTTP_MODULE, NGX_HTTP_LOC_CONF_OFFSET, NGX_RS_MODULE_SIGNATURE,
    nginx_version, ngx_chain_t, ngx_command_t, ngx_conf_t, ngx_http_module_t, ngx_int_t,
    ngx_module_t, ngx_str_t, ngx_uint_t,
@ -46,7 +46,7 @@ struct ModuleConfig {
    db_path: String,
    query: String,
    template_path: String,
-    query_params: Vec<String>, // Variable names to use as query parameters
+    query_params: Vec<(String, String)>, // (param_name, variable_name) pairs
 }

 // Global configuration for shared templates
@ -179,7 +179,7 @@ static mut ngx_http_howto_commands: [ngx_command_t; 6] = [
    },
    ngx_command_t {
        name: ngx_string!("sqlite_param"),
-        type_: (NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1) as ngx_uint_t,
+        type_: (NGX_HTTP_LOC_CONF | NGX_CONF_TAKE1 | NGX_CONF_TAKE2) as ngx_uint_t,
        set: Some(ngx_http_howto_commands_add_param),
        conf: NGX_HTTP_LOC_CONF_OFFSET,
        offset: 0,
@ -272,8 +272,20 @@ extern "C" fn ngx_http_howto_commands_add_param(
    unsafe {
        let conf = &mut *(conf as *mut ModuleConfig);
        let args = (*(*cf).args).elts as *mut ngx_str_t;
-        let param = (*args.add(1)).to_string();
-        conf.query_params.push(param);
+        let nelts = (*(*cf).args).nelts;
+        
+        if nelts == 2 {
+            // Single argument: positional parameter
+            // sqlite_param $arg_id
+            let variable = (*args.add(1)).to_string();
+            conf.query_params.push((String::new(), variable));
+        } else if nelts == 3 {
+            // Two arguments: named parameter
+            // sqlite_param :book_id $arg_id
+            let param_name = (*args.add(1)).to_string();
+            let variable = (*args.add(2)).to_string();
+            conf.query_params.push((param_name, variable));
+        }
    };

    std::ptr::null_mut()
@ -318,7 +330,7 @@ fn load_templates_from_dir(reg: &mut Handlebars, dir_path: &str) -> std::io::Res
 fn execute_query(
    db_path: &str,
    query: &str,
-    params: &[&str],
+    params: &[(String, String)], // (param_name, value) pairs
 ) -> Result<Vec<std::collections::HashMap<String, serde_json::Value>>> {
    let conn = Connection::open(db_path)?;
    let mut stmt = conn.prepare(query)?;
@ -328,13 +340,11 @@ fn execute_query(
        .map(|i| stmt.column_name(i).unwrap_or("").to_string())
        .collect();

-    // Convert params to rusqlite parameters
-    let rusqlite_params: Vec<&dyn rusqlite::ToSql> = params
-        .iter()
-        .map(|p| p as &dyn rusqlite::ToSql)
-        .collect();
-
-    let rows = stmt.query_map(rusqlite_params.as_slice(), |row| {
+    // Bind parameters (either positional or named)
+    let has_named_params = params.iter().any(|(name, _)| !name.is_empty());
+    
+    // Convert row to JSON map
+    let row_to_map = |row: &rusqlite::Row| -> rusqlite::Result<std::collections::HashMap<String, serde_json::Value>> {
        let mut map = std::collections::HashMap::new();
        for (i, col_name) in column_names.iter().enumerate() {
            let value: serde_json::Value = match row.get_ref(i)? {
@ -350,7 +360,8 @@ fn execute_query(
                }
                rusqlite::types::ValueRef::Blob(v) => {
                    // Convert blob to hex string
-                    let hex_string = v.iter()
+                    let hex_string = v
+                        .iter()
                        .map(|b| format!("{:02x}", b))
                        .collect::<String>();
                    serde_json::Value::String(hex_string)
@ -359,7 +370,23 @@ fn execute_query(
            map.insert(col_name.clone(), value);
        }
        Ok(map)
-    })?;
+    };
+    
+    let rows = if has_named_params {
+        // Use named parameters
+        let named_params: Vec<(&str, &dyn rusqlite::ToSql)> = params
+            .iter()
+            .map(|(name, value)| (name.as_str(), value as &dyn rusqlite::ToSql))
+            .collect();
+        stmt.query_map(named_params.as_slice(), row_to_map)?
+    } else {
+        // Use positional parameters
+        let positional_params: Vec<&dyn rusqlite::ToSql> = params
+            .iter()
+            .map(|(_, value)| value as &dyn rusqlite::ToSql)
+            .collect();
+        stmt.query_map(positional_params.as_slice(), row_to_map)?
+    };

    rows.collect()
 }
@ -407,8 +434,8 @@ http_request_handler!(howto_access_handler, |request: &mut http::Request| {
        .unwrap_or("");

    // Resolve query parameters from nginx variables
-    let mut param_values: Vec<String> = Vec::new();
-    for var_name in &co.query_params {
+    let mut param_values: Vec<(String, String)> = Vec::new();
+    for (param_name, var_name) in &co.query_params {
        let value = if var_name.starts_with('$') {
            // It's a variable reference, resolve it from nginx
            let var_name_str = &var_name[1..]; // Remove the '$' prefix
@ -445,19 +472,17 @@ http_request_handler!(howto_access_handler, |request: &mut http::Request| {
            // It's a literal value
            var_name.clone()
        };
-        param_values.push(value);
+        param_values.push((param_name.clone(), value));
    }

    ngx_log_debug_http!(
        request,
-        "executing query with {} parameters: {:?}",
-        param_values.len(),
-        param_values
+        "executing query with {} parameters",
+        param_values.len()
    );

    // Execute the configured SQL query with parameters
-    let param_refs: Vec<&str> = param_values.iter().map(|s| s.as_str()).collect();
-    let results = match execute_query(&co.db_path, &co.query, &param_refs) {
+    let results = match execute_query(&co.db_path, &co.query, &param_values) {
        Ok(results) => results,
        Err(e) => {
            ngx_log_debug_http!(request, "failed to execute query: {}", e);
--- a/start_named_params.sh
+++ b/start_named_params.sh
@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Start script for named parameters example
+
+set -e
+
+echo "📚 Starting Named Parameters Example..."
+echo ""
+
+# Check if database exists
+if [ ! -f "book_catalog.db" ]; then
+    echo "Database not found. Running setup..."
+    ./setup_book_catalog.sh
+    echo ""
+fi
+
+# Check if module is built
+if [ ! -f "target/debug/libsqlite_serve.dylib" ]; then
+    echo "Module not built. Building..."
+    direnv exec "$PWD" cargo build
+    echo ""
+fi
+
+# Start nginx
+echo "Starting nginx on http://localhost:8082"
+./ngx_src/nginx-1.28.0/objs/nginx -c conf/book_named_params.conf -p .
+
+echo ""
+echo "✅ Named Parameters Example is running!"
+echo ""
+echo "Named Parameter Examples:"
+echo "  • http://localhost:8082/book?id=1"
+echo "    Query: SELECT * FROM books WHERE id = :book_id"
+echo "    Param: :book_id = \$arg_id"
+echo ""
+echo "  • http://localhost:8082/genre?genre=Programming"
+echo "    Query: ... WHERE genre = :genre_name"
+echo "    Param: :genre_name = \$arg_genre"
+echo ""
+echo "  • http://localhost:8082/years?min=2015&max=2024"
+echo "    Query: ... WHERE year >= :min_year AND year <= :max_year"
+echo "    Params: :min_year = \$arg_min, :max_year = \$arg_max"
+echo ""
+echo "  • http://localhost:8082/search?q=Rust"
+echo "    Search by title with named parameter"
+echo ""
+echo "  • http://localhost:8082/top-rated?rating=4.7"
+echo "    Filter by minimum rating"
+echo ""
+echo "To stop: ./ngx_src/nginx-1.28.0/objs/nginx -s stop -c conf/book_named_params.conf -p ."
+