resolves #159 - Added mysql subquery support. Added alias to subquery

njord/src/column.rs

@@ -1,53 +1,56 @@
-use crate::{sqlite::select::SelectQueryBuilder, table::Table};
+use crate::query::QueryBuilder;
 
 /// Define the enum to represent a column as either a String or SelectQueryBuilder
 #[derive(Clone)]
-pub enum Column<'a, T: Table + Default> {
+pub enum Column<'a> {
     Text(String),
-    SubQuery(SelectQueryBuilder<'a, T>),
+    // Subquery with alias
+    SubQuery(Box<dyn QueryBuilder<'a> + 'a>, String),
 }
 
 // Implement the build method to convert the enum to a string
-impl<'a, T: Table + Default> Column<'a, T> {
+impl<'a> Column<'a> {
     /// Helper function to convert the columns to a string
     pub fn build(&self) -> String {
         match self {
             Column::Text(text) => text.clone(),
-            Column::SubQuery(sub_query) => "(".to_string() + &sub_query.build_query() + ")",
+            Column::SubQuery(sub_query, alias) => {
+                "(".to_string() + &sub_query.to_sql() + ") AS " + alias
+            }
         }
     }
 }
 
 // Implementation of fmt::Display for Column
-impl<'a, T: Table + Default> std::fmt::Display for Column<'a, T> {
+impl<'a> std::fmt::Display for Column<'a> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", self.build())
     }
 }
 
 // Implementation of PartialEq for Column
-impl<'a, T: Table + Default> PartialEq for Column<'a, T> {
+impl<'a> PartialEq for Column<'a> {
     fn eq(&self, other: &Self) -> bool {
         self.build() == other.build()
     }
 }
 
 // Implementation of PartialEq<String> for Column
-impl<'a, T: Table + Default> PartialEq<String> for Column<'a, T> {
+impl<'a> PartialEq<String> for Column<'a> {
     fn eq(&self, other: &String) -> bool {
         match self {
             Column::Text(text) => text == other,
-            Column::SubQuery(sub_query) => sub_query.build_query() == *other,
+            Column::SubQuery(sub_query, _) => sub_query.to_sql() == *other,
         }
     }
 }
 
 // Implementation of PartialEq<&str> for Column
-impl<'a, T: Table + Default> PartialEq<&str> for Column<'a, T> {
+impl<'a> PartialEq<&str> for Column<'a> {
     fn eq(&self, other: &&str) -> bool {
         match self {
             Column::Text(text) => text == other,
-            Column::SubQuery(sub_query) => sub_query.build_query() == *other,
+            Column::SubQuery(sub_query, _) => sub_query.to_sql() == *other,
         }
     }
 }

njord/src/keys.rs

@@ -43,7 +43,7 @@ use serde::{Deserialize, Deserializer};
 /// # Type Parameters
 ///
 /// * `T` - The type of the primary key value, which can be any type.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct PrimaryKey<T>(T);
 
 impl<T> PrimaryKey<T> {
@@ -216,4 +216,4 @@ impl<T: PartialEq> PartialEq for AutoIncrementPrimaryKey<T> {
     fn eq(&self, other: &Self) -> bool {
         self.0 == other.0
     }
-}
+}

njord/src/mysql/select.rs

@@ -57,15 +57,15 @@ use crate::util::{Join, JoinType};
 /// # Returns
 ///
 /// A `SelectQueryBuilder` instance.
-pub fn select<T: Table + Default>(columns: Vec<Column<T>>) -> SelectQueryBuilder<T> {
+pub fn select<T: Table + Default>(columns: Vec<Column>) -> SelectQueryBuilder<T> {
     SelectQueryBuilder::new(columns)
 }
 
 /// A builder for constructing SELECT queries.
 #[derive(Clone)]
 pub struct SelectQueryBuilder<'a, T: Table + Default> {
     table: Option<T>,
-    columns: Vec<Column<'a, T>>,
+    columns: Vec<Column<'a>>,
     where_condition: Option<Condition<'a>>,
     distinct: bool,
     group_by: Option<Vec<String>>,
@@ -85,7 +85,7 @@ impl<'a, T: Table + Default> SelectQueryBuilder<'a, T> {
     ///
     /// * `conn` - A `PooledConn` to the MySql database.
     /// * `columns` - A vector of strings representing the columns to be selected.
-    pub fn new(columns: Vec<Column<'a, T>>) -> Self {
+    pub fn new(columns: Vec<Column<'a>>) -> Self {
         SelectQueryBuilder {
             table: None,
             columns,
@@ -107,7 +107,7 @@ impl<'a, T: Table + Default> SelectQueryBuilder<'a, T> {
     /// # Arguments
     ///
     /// * `columns` - A vector of strings representing the columns to be selected.
-    pub fn select(mut self, columns: Vec<Column<'a, T>>) -> Self {
+    pub fn select(mut self, columns: Vec<Column<'a>>) -> Self {
         self.columns = columns;
         self
     }

njord/src/sqlite/select.rs

@@ -57,7 +57,7 @@ use crate::util::{Join, JoinType};
 /// A `SelectQueryBuilder` instance.
 pub fn select<'a, T: Table + Default>(
     conn: &'a Connection,
-    columns: Vec<Column<'a, T>>,
+    columns: Vec<Column<'a>>,
 ) -> SelectQueryBuilder<'a, T> {
     SelectQueryBuilder::new(conn, columns)
 }
@@ -67,7 +67,7 @@ pub fn select<'a, T: Table + Default>(
 pub struct SelectQueryBuilder<'a, T: Table + Default> {
     conn: &'a Connection,
     table: Option<T>,
-    columns: Vec<Column<'a, T>>,
+    columns: Vec<Column<'a>>,
     where_condition: Option<Condition<'a>>,
     distinct: bool,
     group_by: Option<Vec<String>>,
@@ -87,7 +87,7 @@ impl<'a, T: Table + Default> SelectQueryBuilder<'a, T> {
     ///
     /// * `conn` - A `rusqlite::Connection` to the SQLite database.
     /// * `columns` - A vector of strings representing the columns to be selected.
-    pub fn new(conn: &'a Connection, columns: Vec<Column<'a, T>>) -> Self {
+    pub fn new(conn: &'a Connection, columns: Vec<Column<'a>>) -> Self {
         SelectQueryBuilder {
             conn,
             table: None,
@@ -110,7 +110,7 @@ impl<'a, T: Table + Default> SelectQueryBuilder<'a, T> {
     /// # Arguments
     ///
     /// * `columns` - A vector of strings representing the columns to be selected.
-    pub fn select(mut self, columns: Vec<Column<'a, T>>) -> Self {
+    pub fn select(mut self, columns: Vec<Column<'a>>) -> Self {
         self.columns = columns;
         self
     }

njord/tests/mysql/mod.rs

@@ -5,7 +5,7 @@ mod select_joins_test;
 mod select_test;
 mod update_test;
 
-use njord::keys::{AutoIncrementPrimaryKey, PrimaryKey};
+use njord::keys::AutoIncrementPrimaryKey;
 use njord::table::Table;
 use njord_derive::Table;
 
@@ -18,7 +18,7 @@ pub struct User {
     pub address: String,
 }
 
-#[derive(Table)]
+#[derive(Table, Clone)]
 #[table_name = "users"]
 pub struct UserWithSubQuery {
     pub id: AutoIncrementPrimaryKey<usize>,
@@ -28,22 +28,23 @@ pub struct UserWithSubQuery {
     pub additional_address: String,
 }
 
-#[derive(Table)]
+#[derive(Table, Clone)]
 #[table_name = "categories"]
 pub struct Category {
-    pub id: PrimaryKey<usize>,
+    pub id: AutoIncrementPrimaryKey<usize>,
     pub name: String,
 }
 
-#[derive(Table)]
+#[derive(Table, Clone)]
 #[table_name = "products"]
 pub struct Product {
-    pub id: PrimaryKey<usize>,
+    pub id: AutoIncrementPrimaryKey<usize>,
     pub name: String,
     pub description: String,
     pub price: f64,
     pub stock_quantity: usize,
-    pub category: Category, // one-to-one relationship
+    // pub category: Category, // one-to-one relationship
+    pub category_id: usize,
     pub discount: f64,
 }
 
@@ -54,3 +55,14 @@ pub struct UsersWithJoin {
     price: f64,
     name: String,
 }
+
+#[derive(Table)]
+#[table_name = "categories"]
+pub struct CategoryWithJoin {
+    name: String,
+    description: String,
+    price: f64,
+    stock_quantity: usize,
+    discount: f64,
+    category_name: String,
+}