Refactors importer to use core stuff

31 files changed, 497 insertions, 0 deletions

diff --git a/backend/core/src/queries/accounts/delete_all.rs b/backend/core/src/queries/accounts/delete_all.rs
new file mode 100644
index 0000000..84d7bf6
--- /dev/null
+++ b/backend/core/src/queries/accounts/delete_all.rs
@@ -0,0 +1,11 @@
+use anyhow::{Context, Result};
+use diesel::{RunQueryDsl, SqliteConnection};
+
+use crate::schema::accounts::dsl::accounts;
+
+pub fn delete_all_accounts(connection: &mut SqliteConnection) -> Result<usize> {
+    let num_rows_deleted = diesel::delete(accounts)
+        .execute(connection)
+        .with_context(|| "failed to delete all accounts")?;
+    Ok(num_rows_deleted)
+}
diff --git a/backend/core/src/queries/accounts/get_all.rs b/backend/core/src/queries/accounts/get_all.rs
new file mode 100644
index 0000000..ab53729
--- /dev/null
+++ b/backend/core/src/queries/accounts/get_all.rs
@@ -0,0 +1,10 @@
+use anyhow::{Context, Result};
+use crate::{models::account::Account, schema::accounts::dsl::accounts};
+use diesel::{QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection};
+
+pub fn get_all_accounts(connection: &mut SqliteConnection) -> Result<Vec<Account>> {
+    let all_accounts = accounts.select(Account::as_select())
+        .load(connection)
+        .with_context(|| "failed to get all accounts")?;
+    Ok(all_accounts)
+}
diff --git a/backend/core/src/queries/accounts/insert.rs b/backend/core/src/queries/accounts/insert.rs
new file mode 100644
index 0000000..7020b68
--- /dev/null
+++ b/backend/core/src/queries/accounts/insert.rs
@@ -0,0 +1,28 @@
+use anyhow::{Context, Result};
+use crate::{
+    models::account::Account,
+    schema::accounts::dsl::accounts as accounts_table,
+};
+use diesel::prelude::*;
+
+pub fn insert_accounts(
+    accounts: &[Account],
+    connection: &mut SqliteConnection,
+) -> Result<usize> {
+    let num_accounts_inserted = diesel::insert_into(accounts_table)
+        .values(accounts)
+        .execute(connection)
+        .with_context(|| err_msg(accounts))?;
+    Ok(num_accounts_inserted)
+}
+
+fn err_msg(accounts: &[Account]) -> String {
+    format!(
+        "failed to insert accounts: [{}]",
+        accounts
+            .iter()
+            .map(|a| format!("\"{}\": \"{}\"", a.id, a.name))
+            .collect::<Vec<String>>()
+            .join(", ")
+    )
+}
diff --git a/backend/core/src/queries/accounts/mod.rs b/backend/core/src/queries/accounts/mod.rs
new file mode 100644
index 0000000..222b180
--- /dev/null
+++ b/backend/core/src/queries/accounts/mod.rs
@@ -0,0 +1,7 @@
+mod delete_all;
+mod get_all;
+mod insert;
+
+pub use delete_all::delete_all_accounts;
+pub use get_all::get_all_accounts;
+pub use insert::insert_accounts;
diff --git a/backend/core/src/queries/budget_updates/delete_all.rs b/backend/core/src/queries/budget_updates/delete_all.rs
new file mode 100644
index 0000000..b7ad082
--- /dev/null
+++ b/backend/core/src/queries/budget_updates/delete_all.rs
@@ -0,0 +1,11 @@
+use anyhow::{Context, Result};
+use diesel::{RunQueryDsl, SqliteConnection};
+
+use crate::schema::budget_updates::dsl::budget_updates;
+
+pub fn delete_all_budget_updates(connection: &mut SqliteConnection) -> Result<usize> {
+    let num_rows_deleted = diesel::delete(budget_updates)
+        .execute(connection)
+        .with_context(|| "failed to delete all budget updates")?;
+    Ok(num_rows_deleted)
+}
diff --git a/backend/core/src/queries/budget_updates/get_all.rs b/backend/core/src/queries/budget_updates/get_all.rs
new file mode 100644
index 0000000..9c9310b
--- /dev/null
+++ b/backend/core/src/queries/budget_updates/get_all.rs
@@ -0,0 +1,16 @@
+use anyhow::{Context, Result};
+use crate::{
+    models::budget_update::BudgetUpdate,
+    schema::budget_updates::dsl::budget_updates as budget_updates_table,
+};
+use diesel::{QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection};
+
+pub fn get_all_budget_updates(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<BudgetUpdate>> {
+    let all_budget_updates = budget_updates_table
+        .select(BudgetUpdate::as_select())
+        .load::<BudgetUpdate>(connection)
+        .with_context(|| "failed to get all budget updates")?;
+    Ok(all_budget_updates)
+}
diff --git a/backend/core/src/queries/budget_updates/get_first_with_date.rs b/backend/core/src/queries/budget_updates/get_first_with_date.rs
new file mode 100644
index 0000000..1df3ae2
--- /dev/null
+++ b/backend/core/src/queries/budget_updates/get_first_with_date.rs
@@ -0,0 +1,22 @@
+use anyhow::{Context, Result};
+use crate::{
+    models::budget_update::BudgetUpdate,
+    schema::budget_updates::{
+        self as budget_updates_schema, dsl::budget_updates as budget_updates_table,
+    },
+};
+use diesel::{
+    ExpressionMethods, QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection,
+};
+
+pub fn get_first_budget_update_with_date(
+    date: &str,
+    connection: &mut SqliteConnection,
+) -> Result<BudgetUpdate> {
+    let first_budget_update = budget_updates_table
+        .select(BudgetUpdate::as_select())
+        .filter(budget_updates_schema::date.eq(date))
+        .first(connection)
+        .with_context(|| format!("failed to get first budget update with date {}", date))?;
+    Ok(first_budget_update)
+}
diff --git a/backend/core/src/queries/budget_updates/get_most_recent_with_category_id.rs b/backend/core/src/queries/budget_updates/get_most_recent_with_category_id.rs
new file mode 100644
index 0000000..4e13c50
--- /dev/null
+++ b/backend/core/src/queries/budget_updates/get_most_recent_with_category_id.rs
@@ -0,0 +1,21 @@
+use anyhow::{Context, Result};
+use crate::{
+    models::date_time_utc::DateTimeUtc,
+    schema::budget_updates::{
+        self as budget_updates_schema, dsl::budget_updates as budget_updates_table,
+    },
+};
+use diesel::{dsl::max, ExpressionMethods, QueryDsl, RunQueryDsl, SqliteConnection};
+
+pub fn get_most_recent_budget_update_date_with_category_id(
+    category_id: i32,
+    connection: &mut SqliteConnection,
+) -> Result<Option<String>> {
+    let most_recent_date = budget_updates_table
+        .select(max(budget_updates_schema::date))
+        .filter(budget_updates_schema::category_id.eq(category_id))
+        .filter(budget_updates_schema::date.le(DateTimeUtc::now().to_day_str()))
+        .first(connection)
+        .with_context(|| format!("failed to get most recent budget update date with category ID {}", category_id))?;
+    Ok(most_recent_date)
+}
diff --git a/backend/core/src/queries/budget_updates/insert.rs b/backend/core/src/queries/budget_updates/insert.rs
new file mode 100644
index 0000000..e8ae271
--- /dev/null
+++ b/backend/core/src/queries/budget_updates/insert.rs
@@ -0,0 +1,28 @@
+use anyhow::{Context, Result};
+use crate::{
+    models::budget_update::BudgetUpdate,
+    schema::budget_updates::dsl::budget_updates as budget_updates_table,
+};
+use diesel::prelude::*;
+
+pub fn insert_budget_updates(
+    budget_updates: &[BudgetUpdate],
+    connection: &mut SqliteConnection,
+) -> Result<usize> {
+    let num_rows_inserted = diesel::insert_into(budget_updates_table)
+        .values(budget_updates)
+        .execute(connection)
+        .with_context(|| err_msg(budget_updates))?;
+    Ok(num_rows_inserted)
+}
+
+fn err_msg(budget_updates: &[BudgetUpdate]) -> String {
+    format!(
+        "failed to insert budget updates: [{}]",
+        budget_updates
+            .iter()
+            .map(|a| a.id.to_string())
+            .collect::<Vec<String>>()
+            .join(", ")
+    )
+}
diff --git a/backend/core/src/queries/budget_updates/mod.rs b/backend/core/src/queries/budget_updates/mod.rs
new file mode 100644
index 0000000..337197e
--- /dev/null
+++ b/backend/core/src/queries/budget_updates/mod.rs
@@ -0,0 +1,11 @@
+mod delete_all;
+mod get_all;
+mod get_first_with_date;
+mod get_most_recent_with_category_id;
+mod insert;
+
+pub use delete_all::delete_all_budget_updates;
+pub use get_all::get_all_budget_updates;
+pub use get_first_with_date::get_first_budget_update_with_date;
+pub use get_most_recent_with_category_id::get_most_recent_budget_update_date_with_category_id;
+pub use insert::insert_budget_updates;
diff --git a/backend/core/src/queries/categories/delete_all.rs b/backend/core/src/queries/categories/delete_all.rs
new file mode 100644
index 0000000..1fd2581
--- /dev/null
+++ b/backend/core/src/queries/categories/delete_all.rs
@@ -0,0 +1,11 @@
+use anyhow::{Context, Result};
+use diesel::{RunQueryDsl, SqliteConnection};
+
+use crate::schema::categories::dsl::categories;
+
+pub fn delete_all_categories(connection: &mut SqliteConnection) -> Result<usize> {
+    let num_rows_deleted = diesel::delete(categories)
+        .execute(connection)
+        .with_context(|| "failed to delete all categories")?;
+    Ok(num_rows_deleted)
+}
diff --git a/backend/core/src/queries/categories/get_all.rs b/backend/core/src/queries/categories/get_all.rs
new file mode 100644
index 0000000..431ed9c
--- /dev/null
+++ b/backend/core/src/queries/categories/get_all.rs
@@ -0,0 +1,11 @@
+use anyhow::{Context, Result};
+use crate::{models::category::Category, schema::categories::dsl::categories as categories_table};
+use diesel::{QueryDsl, RunQueryDsl, SelectableHelper, SqliteConnection};
+
+pub fn get_all_categories(connection: &mut SqliteConnection) -> Result<Vec<Category>> {
+    let all_categories = categories_table
+        .select(Category::as_select())
+        .load(connection)
+        .with_context(|| "failed to get all categories")?;
+    Ok(all_categories)
+}
diff --git a/backend/core/src/queries/categories/get_all_balances.rs b/backend/core/src/queries/categories/get_all_balances.rs
new file mode 100644
index 0000000..da4b0cd
--- /dev/null
+++ b/backend/core/src/queries/categories/get_all_balances.rs
@@ -0,0 +1,47 @@
+use anyhow::{Context, Result};
+use crate::{models::category_balance::CategoryBalance, queries::{
+        budget_updates::get_all_budget_updates,
+        categories::get_all_categories,
+        category_transfers::{
+            sum_category_transfer_quantity_per_from_category_id,
+            sum_category_transfer_quantity_per_to_category_id,
+        },
+        transaction_categorisations::sum_transaction_categorisation_quantity_per_category_id,
+    }, utils::calculate_category_balance};
+use diesel::SqliteConnection;
+
+pub fn get_all_category_balances(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<CategoryBalance>> {
+    get_all_category_balances_without_context(connection)
+        .with_context(|| "failed to get all category balances")
+}
+
+fn get_all_category_balances_without_context(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<CategoryBalance>> {
+    let categories = get_all_categories(connection)?;
+    let transaction_sums = sum_transaction_categorisation_quantity_per_category_id(connection)?;
+    let category_transfer_from_sums =
+        sum_category_transfer_quantity_per_from_category_id(connection)?;
+    let category_transfer_to_sums = sum_category_transfer_quantity_per_to_category_id(connection)?;
+    let budget_updates = get_all_budget_updates(connection)?;
+
+    let mut balances = Vec::<CategoryBalance>::new();
+    for category in categories {
+        let balance = calculate_category_balance(
+            &category,
+            &transaction_sums,
+            &category_transfer_from_sums,
+            &category_transfer_to_sums,
+            &budget_updates,
+        );
+
+        balances.push(CategoryBalance {
+            category_id: category.id,
+            balance: balance.try_into().unwrap(),
+        })
+    }
+
+    Ok(balances)
+}
diff --git a/backend/core/src/queries/categories/get_all_ids.rs b/backend/core/src/queries/categories/get_all_ids.rs
new file mode 100644
index 0000000..8505e71
--- /dev/null
+++ b/backend/core/src/queries/categories/get_all_ids.rs
@@ -0,0 +1,11 @@
+use anyhow::{Context, Result};
+use crate::schema::categories::{self as categories_schema, dsl::categories as categories_table};
+use diesel::{QueryDsl, RunQueryDsl, SqliteConnection};
+
+pub fn get_all_category_ids(connection: &mut SqliteConnection) -> Result<Vec<i32>> {
+    let all_category_ids = categories_table
+        .select(categories_schema::id)
+        .load(connection)
+        .with_context(|| "failed to get all category IDs")?;
+    Ok(all_category_ids)
+}
diff --git a/backend/core/src/queries/categories/get_most_recent_budget_per_category_id.rs b/backend/core/src/queries/categories/get_most_recent_budget_per_category_id.rs
new file mode 100644
index 0000000..b8f1a76
--- /dev/null
+++ b/backend/core/src/queries/categories/get_most_recent_budget_per_category_id.rs
@@ -0,0 +1,47 @@
+use anyhow::{Context, Result};
+use crate::{models::{budget::Budget, category_budget::CategoryBudget}, queries::{
+    budget_updates::{
+        get_first_budget_update_with_date, get_most_recent_budget_update_date_with_category_id,
+    },
+    categories::get_all_category_ids,
+}};
+use diesel::SqliteConnection;
+
+pub fn get_most_recent_category_budget_per_category_id(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<CategoryBudget>> {
+    get_most_recent_category_budget_per_category_id_without_context(connection)
+        .with_context(|| "failed to get most recent category budget per category ID")
+}
+
+fn get_most_recent_category_budget_per_category_id_without_context(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<CategoryBudget>> {
+    let category_ids: Vec<i32> = get_all_category_ids(connection)?;
+
+    let mut budgets = Vec::<CategoryBudget>::new();
+    for category_id in category_ids {
+        let most_recent_budget_update_date =
+            get_most_recent_budget_update_date_with_category_id(category_id, connection)?;
+
+        if most_recent_budget_update_date.is_none() {
+            budgets.push(CategoryBudget {
+                category_id,
+                budget: Option::None,
+            });
+            continue;
+        }
+
+        let most_recent_budget_update = get_first_budget_update_with_date(
+            most_recent_budget_update_date.unwrap().as_str(),
+            connection,
+        )?;
+
+        budgets.push(CategoryBudget {
+            category_id,
+            budget: Some(Budget::from(&most_recent_budget_update)),
+        });
+    }
+
+    Ok(budgets)
+}
diff --git a/backend/core/src/queries/categories/insert.rs b/backend/core/src/queries/categories/insert.rs
new file mode 100644
index 0000000..bccba72
--- /dev/null
+++ b/backend/core/src/queries/categories/insert.rs
@@ -0,0 +1,28 @@
+use anyhow::{Context, Result};
+use crate::{
+    models::category::Category,
+    schema::categories::dsl::categories as categories_table,
+};
+use diesel::prelude::*;
+
+pub fn insert_categories(
+    categories: &[Category],
+    connection: &mut SqliteConnection,
+) -> Result<usize> {
+    let num_categories_inserted = diesel::insert_into(categories_table)
+        .values(categories)
+        .execute(connection)
+        .with_context(|| err_msg(categories))?;
+    Ok(num_categories_inserted)
+}
+
+fn err_msg(categories: &[Category]) -> String {
+    format!(
+        "failed to insert categories: [{}]",
+        categories
+            .iter()
+            .map(|a| format!("\"{}\": \"{}\"", a.id, a.name))
+            .collect::<Vec<String>>()
+            .join(", ")
+    )
+}
diff --git a/backend/core/src/queries/categories/mod.rs b/backend/core/src/queries/categories/mod.rs
new file mode 100644
index 0000000..edeeebf
--- /dev/null
+++ b/backend/core/src/queries/categories/mod.rs
@@ -0,0 +1,13 @@
+mod delete_all;
+mod get_all;
+mod get_all_balances;
+mod get_all_ids;
+mod get_most_recent_budget_per_category_id;
+mod insert;
+
+pub use delete_all::delete_all_categories;
+pub use get_all::get_all_categories;
+pub use get_all_balances::get_all_category_balances;
+pub use get_all_ids::get_all_category_ids;
+pub use get_most_recent_budget_per_category_id::get_most_recent_category_budget_per_category_id;
+pub use insert::insert_categories;
diff --git a/backend/core/src/queries/category_transfers/delete_all.rs b/backend/core/src/queries/category_transfers/delete_all.rs
new file mode 100644
index 0000000..406b80b
--- /dev/null
+++ b/backend/core/src/queries/category_transfers/delete_all.rs
@@ -0,0 +1,7 @@
+use diesel::{result::Error, RunQueryDsl, SqliteConnection};
+
+use crate::schema::category_transfers::dsl::category_transfers;
+
+pub fn delete_all_category_transfers(connection: &mut SqliteConnection) -> Result<usize, Error> {
+    diesel::delete(category_transfers).execute(connection)
+}
diff --git a/backend/core/src/queries/category_transfers/insert.rs b/backend/core/src/queries/category_transfers/insert.rs
new file mode 100644
index 0000000..e1db167
--- /dev/null
+++ b/backend/core/src/queries/category_transfers/insert.rs
@@ -0,0 +1,15 @@
+use crate::{
+    models::category_transfer::CategoryTransfer,
+    schema::category_transfers::dsl::category_transfers as category_transfers_table,
+};
+use diesel::prelude::*;
+use diesel::result::Error;
+
+pub fn insert_category_transfers(
+    category_transfers: &[CategoryTransfer],
+    connection: &mut SqliteConnection,
+) -> Result<usize, Error> {
+    diesel::insert_into(category_transfers_table)
+        .values(category_transfers)
+        .execute(connection)
+}
diff --git a/backend/core/src/queries/category_transfers/mod.rs b/backend/core/src/queries/category_transfers/mod.rs
new file mode 100644
index 0000000..68f32f4
--- /dev/null
+++ b/backend/core/src/queries/category_transfers/mod.rs
@@ -0,0 +1,9 @@
+mod delete_all;
+mod insert;
+mod sum_quantity_per_from_category_id;
+mod sum_quantity_per_to_category_id;
+
+pub use delete_all::delete_all_category_transfers;
+pub use insert::insert_category_transfers;
+pub use sum_quantity_per_from_category_id::sum_category_transfer_quantity_per_from_category_id;
+pub use sum_quantity_per_to_category_id::sum_category_transfer_quantity_per_to_category_id;
diff --git a/backend/core/src/queries/category_transfers/sum_quantity_per_from_category_id.rs b/backend/core/src/queries/category_transfers/sum_quantity_per_from_category_id.rs
new file mode 100644
index 0000000..cd4137d
--- /dev/null
+++ b/backend/core/src/queries/category_transfers/sum_quantity_per_from_category_id.rs
@@ -0,0 +1,17 @@
+use crate::schema::category_transfers::{
+    self as category_transfers_schema,
+    dsl::category_transfers as category_transfers_table,
+};
+use diesel::{dsl::sum, result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
+
+pub fn sum_category_transfer_quantity_per_from_category_id(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<(i32, Option<i64>)>, Error> {
+    category_transfers_table
+        .group_by(category_transfers_schema::from_category_id)
+        .select((
+            category_transfers_schema::from_category_id,
+            sum(category_transfers_schema::quantity),
+        ))
+        .load::<(i32, Option<i64>)>(connection)
+}
diff --git a/backend/core/src/queries/category_transfers/sum_quantity_per_to_category_id.rs b/backend/core/src/queries/category_transfers/sum_quantity_per_to_category_id.rs
new file mode 100644
index 0000000..f5fb561
--- /dev/null
+++ b/backend/core/src/queries/category_transfers/sum_quantity_per_to_category_id.rs
@@ -0,0 +1,17 @@
+use crate::schema::category_transfers::{
+    self as category_transfers_schema,
+    dsl::category_transfers as category_transfers_table,
+};
+use diesel::{dsl::sum, result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
+
+pub fn sum_category_transfer_quantity_per_to_category_id(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<(i32, Option<i64>)>, Error> {
+    category_transfers_table
+        .group_by(category_transfers_schema::to_category_id)
+        .select((
+            category_transfers_schema::to_category_id,
+            sum(category_transfers_schema::quantity),
+        ))
+        .load::<(i32, Option<i64>)>(connection)
+}
diff --git a/backend/core/src/queries/clear.rs b/backend/core/src/queries/clear.rs
new file mode 100644
index 0000000..dbe0f84
--- /dev/null
+++ b/backend/core/src/queries/clear.rs
@@ -0,0 +1,19 @@
+use crate::queries::{
+    accounts::delete_all_accounts,
+    budget_updates::delete_all_budget_updates,
+    categories::delete_all_categories,
+    category_transfers::delete_all_category_transfers,
+    transactions::delete_all_transactions,
+    transaction_categorisations::delete_all_transaction_categorisations,
+};
+use diesel::{result::Error, SqliteConnection};
+
+pub fn clear(connection: &mut SqliteConnection) -> Result<(), Error> {
+    delete_all_accounts(connection)?;
+    delete_all_budget_updates(connection)?;
+    delete_all_categories(connection)?;
+    delete_all_category_transfers(connection)?;
+    delete_all_transactions(connection)?;
+    delete_all_transaction_categorisations(connection)?;
+    Ok(())
+}
diff --git a/backend/core/src/queries/mod.rs b/backend/core/src/queries/mod.rs
new file mode 100644
index 0000000..f0852ce
--- /dev/null
+++ b/backend/core/src/queries/mod.rs
@@ -0,0 +1,7 @@
+pub mod accounts;
+pub mod budget_updates;
+pub mod categories;
+pub mod category_transfers;
+pub mod clear;
+pub mod transactions;
+pub mod transaction_categorisations;
diff --git a/backend/core/src/queries/transaction_categorisations/delete_all.rs b/backend/core/src/queries/transaction_categorisations/delete_all.rs
new file mode 100644
index 0000000..e80a0ca
--- /dev/null
+++ b/backend/core/src/queries/transaction_categorisations/delete_all.rs
@@ -0,0 +1,7 @@
+use diesel::{result::Error, RunQueryDsl, SqliteConnection};
+
+use crate::schema::transaction_categorisations::dsl::transaction_categorisations;
+
+pub fn delete_all_transaction_categorisations(connection: &mut SqliteConnection) -> Result<usize, Error> {
+    diesel::delete(transaction_categorisations).execute(connection)
+}
diff --git a/backend/core/src/queries/transaction_categorisations/insert.rs b/backend/core/src/queries/transaction_categorisations/insert.rs
new file mode 100644
index 0000000..3da1c33
--- /dev/null
+++ b/backend/core/src/queries/transaction_categorisations/insert.rs
@@ -0,0 +1,15 @@
+use crate::{
+    models::transaction_categorisation::TransactionCategorisation,
+    schema::transaction_categorisations::dsl::transaction_categorisations as transaction_categorisations_table,
+};
+use diesel::prelude::*;
+use diesel::result::Error;
+
+pub fn insert_transaction_categorisations(
+    transaction_categorisations: &[TransactionCategorisation],
+    connection: &mut SqliteConnection,
+) -> Result<usize, Error> {
+    diesel::insert_into(transaction_categorisations_table)
+        .values(transaction_categorisations)
+        .execute(connection)
+}
diff --git a/backend/core/src/queries/transaction_categorisations/mod.rs b/backend/core/src/queries/transaction_categorisations/mod.rs
new file mode 100644
index 0000000..3664fa6
--- /dev/null
+++ b/backend/core/src/queries/transaction_categorisations/mod.rs
@@ -0,0 +1,7 @@
+mod delete_all;
+mod insert;
+mod sum_quantity_per_category_id;
+
+pub use delete_all::delete_all_transaction_categorisations;
+pub use insert::insert_transaction_categorisations;
+pub use sum_quantity_per_category_id::sum_transaction_categorisation_quantity_per_category_id;
diff --git a/backend/core/src/queries/transaction_categorisations/sum_quantity_per_category_id.rs b/backend/core/src/queries/transaction_categorisations/sum_quantity_per_category_id.rs
new file mode 100644
index 0000000..7f93e0c
--- /dev/null
+++ b/backend/core/src/queries/transaction_categorisations/sum_quantity_per_category_id.rs
@@ -0,0 +1,17 @@
+use crate::schema::transaction_categorisations::{
+    self as transaction_categorisations_schema,
+    dsl::transaction_categorisations as transaction_categorisations_table,
+};
+use diesel::{dsl::sum, result::Error, QueryDsl, RunQueryDsl, SqliteConnection};
+
+pub fn sum_transaction_categorisation_quantity_per_category_id(
+    connection: &mut SqliteConnection,
+) -> Result<Vec<(i32, Option<i64>)>, Error> {
+    transaction_categorisations_table
+        .group_by(transaction_categorisations_schema::category_id)
+        .select((
+            transaction_categorisations_schema::category_id,
+            sum(transaction_categorisations_schema::quantity),
+        ))
+        .load::<(i32, Option<i64>)>(connection)
+}
diff --git a/backend/core/src/queries/transactions/delete_all.rs b/backend/core/src/queries/transactions/delete_all.rs
new file mode 100644
index 0000000..43b7976
--- /dev/null
+++ b/backend/core/src/queries/transactions/delete_all.rs
@@ -0,0 +1,7 @@
+use diesel::{result::Error, RunQueryDsl, SqliteConnection};
+
+use crate::schema::transactions::dsl::transactions;
+
+pub fn delete_all_transactions(connection: &mut SqliteConnection) -> Result<usize, Error> {
+    diesel::delete(transactions).execute(connection)
+}
diff --git a/backend/core/src/queries/transactions/insert.rs b/backend/core/src/queries/transactions/insert.rs
new file mode 100644
index 0000000..32f3dc2
--- /dev/null
+++ b/backend/core/src/queries/transactions/insert.rs
@@ -0,0 +1,15 @@
+use crate::{
+    models::transaction::Transaction,
+    schema::transactions::dsl::transactions as transactions_table,
+};
+use diesel::prelude::*;
+use diesel::result::Error;
+
+pub fn insert_transactions(
+    transactions: &[Transaction],
+    connection: &mut SqliteConnection,
+) -> Result<usize, Error> {
+    diesel::insert_into(transactions_table)
+        .values(transactions)
+        .execute(connection)
+}
diff --git a/backend/core/src/queries/transactions/mod.rs b/backend/core/src/queries/transactions/mod.rs
new file mode 100644
index 0000000..40855f3
--- /dev/null
+++ b/backend/core/src/queries/transactions/mod.rs
@@ -0,0 +1,5 @@
+mod delete_all;
+mod insert;
+
+pub use delete_all::delete_all_transactions;
+pub use insert::insert_transactions;