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//! # About //! This crate is intended to be easy to use for creating //! SQL-Queries dynamically as you need it. //! //! # Usage //! For creating a simple SELECT-Query you first need to add //! `query_builder = "*"` to your `Cargo.toml` file (you may of cource replace * with any version)<br> //! In your code write `extern crate query_builder` and `use query_builder::*` to //! import all structs and enums. <br> //! Finally creating the [`SelectQuery`] looks like this: //! //! ``` //! use query_builder::SelectQuery; //! //! let query = SelectQuery::select(&["*"]).from("users"); //! // make sure the query looks like expected //! assert_eq!(query.as_string(), "SELECT * FROM users"); //! ``` //! <br> //! Creating a [`InsertQuery`] works similar: //! //! ``` //! use query_builder::{InsertQuery, Value}; //! //! // create the basic query //! let mut query = InsertQuery::into("users"); //! // add values to the query //! query.values.insert("name", Value::Varchar("george")); //! //! // make sure that the query looks like expected //! assert_eq!(query.as_string(), "INSERT INTO users(name) VALUES('george')"); //! ``` //! <br> //! More detailed explanations and examples can be found at the corresponding sections //! to the structs and enums //! //! [`SelectQuery`]: ./struct.SelectQuery.html //! [`InsertQuery`]: ./struct.InsertQuery.html //! [`Value`]: ./enum.Value.html // std imports use std::collections::BTreeMap; use std::fmt::{Display, Formatter, Result as FormatResult}; #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd)] /// Enum representing common SQL-datatypes pub enum Value<'c> { Varchar(&'c str), Bool(bool), Tinyint(i8), UnsignedTinyint(u8), Smallint(i16), UnsignedSmallint(u16), Int(i32), UnsignedInt(u32), Bigint(i64), UnsignedBigint(u64), } #[allow(unused_assignments)] impl<'c> Value<'c> { /// Convert the Value to a [`String`] /// /// ## Example /// /// ``` /// use query_builder::Value; /// /// // Put single quotes around the varchar to not conflict with e.g. MySQL when inserting data /// let v = Value::Varchar("steven"); /// assert_eq!(v.as_string(), "'steven'"); /// /// // Bools are written in caps to make them stand out in queries /// let v = Value::Bool(true); /// assert_eq!(v.as_string(), "TRUE"); /// /// // applies to all numeric Values /// let v = Value::Int(42); /// assert_eq!(v.as_string(), "42"); /// ``` /// /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html /// pub fn as_string(&self) -> String { match *self { Value::Varchar(v) => format!("'{}'", v), Value::Bool(b) => if b { "TRUE".to_string() } else { "FALSE".to_string() }, Value::Tinyint(t) => format!("{}", t), Value::UnsignedTinyint(ut) => format!("{}", ut), Value::Smallint(s) => format!("{}", s), Value::UnsignedSmallint(us) => format!("{}", us), Value::Int(i) => format!("{}", i), Value::UnsignedInt(ui) => format!("{}", ui), Value::Bigint(bi) => format!("{}", bi), Value::UnsignedBigint(ubi) => format!("{}", ubi), } } } impl<'c> Display for Value<'c> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[derive(Debug, Clone, Ord, PartialOrd, Eq, PartialEq)] /// Enum representing the ways to combine conditional parts of a query pub enum Condition { And, Or } impl Display for Condition { fn fmt(&self, f: &mut Formatter) -> FormatResult { match *self { Condition::And => write!(f, "AND"), Condition::Or => write!(f, "OR"), } } } #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd)] /// Representing the way to format the ORDER BY clause of some queries pub enum OrderBy<'b> { Row(&'b str), Expression(&'b str), } impl<'b> OrderBy<'b> { /// Display the [`OrderBy`] clause as a [`String`] /// Currently it doesen't matter if you used [`OrderBy::Row`] or /// [`OrderBy::Expression`] as both result in the exat same [`String`] though /// this might change in the future /// /// [`OrderBy`]: ./enum.OrderBy.html /// [`String`]: https://www.doc.rust-lang.org/std/string/struct.String.html /// [`OrderBy::Row`]: ./enum.OrderBy.html#variant.Row /// [`OrderBy::Expression`]: ./enum.OrderBy.html#variant.Expression pub fn as_string(&self) -> String { match *self { OrderBy::Row(r) => format!("ORDER BY {}", r), OrderBy::Expression(e) => format!("ORDER BY {}", e), } } } impl<'b> Display for OrderBy<'b> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[derive(Debug)] /// Struct representing an WHERE-Clause /// /// pub struct WhereClause<'a, 'b> { tbl: &'a str, cond: Value<'b>, how: Condition, } impl<'a, 'b> WhereClause<'a, 'b> { /// Creates a new WHERE-clause /// /// If the Value of `how` is none when initializing the clause, [`Condition::And`] /// is assumed and used for the clause. /// /// /// /// *Note:* If the [`WhereClause`] is the first one to be inserted in the string of an query, /// the condition will be left out. /// /// [`WhereClause`]: ./struct.WhereClause.html /// [`Condition::And`]: ./enum.Condition.html#variant.And /// pub fn new(table: &'a str, cond: Value<'b>, how: Option<Condition>) -> WhereClause<'a, 'b> { if let Some(c) = how { WhereClause { tbl: table, cond: cond, how: c } } else { WhereClause { tbl: table, cond: cond, how: Condition::And, } } } /// Returns a [`String`] representing the [`WhereClause`] with it's condition part /// The returned [`String`] is also the default representation returned when calling the /// [`Display`] trait functions on this struct. /// /// ## Example /// /// ``` /// use query_builder::{WhereClause, Condition, Value}; /// /// let wclause = WhereClause::new("user", Value::Varchar("gerald"), Some(Condition::Or)); /// /// assert_eq!(wclause.as_string(), "OR user = 'gerald'") /// ``` /// /// [`WhereClause`]: ./struct.WhereClause.html /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html /// [`Display`]: https://doc.rust-lang.org/std/fmt/trait.Display.html pub fn as_string(&self) -> String { format!("{} {} = {}", self.how, self.tbl, self.cond) } /// Returns a [`String`] representing the [`WhereClause`] without it's condition part /// but with the `WHERE` phrase in the beginning /// /// ## Example /// /// ``` /// use query_builder::{WhereClause, Value}; /// /// let clause = WhereClause::new("user", Value::Varchar("thomas"), None); /// /// assert_eq!(clause.as_string_no_cond_with_prefix(), "WHERE user = 'thomas'") /// ``` /// /// [`WhereClause`]: ./struct.WhereClause.html /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html pub fn as_string_no_cond_with_prefix(&self) -> String { format!("WHERE {} = {}", self.tbl, self.cond) } /// Returns a [`String`] representing the [`WhereClause`] without `WHERE` prefix and /// without it's conditional parts /// /// ## Example /// /// ``` /// use query_builder::{WhereClause, Value}; /// /// let clause = WhereClause::new("user", Value::Varchar("jeanny"), None); /// /// assert_eq!(clause.as_string_no_cond(), "user = 'jeanny'") /// ``` /// /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html /// [`WhereClause`]: ./struct.WhereClause.html pub fn as_string_no_cond(&self) -> String { format!("{} = {}", self.tbl, self.cond) } } impl<'a, 'b> Display for WhereClause<'a, 'b> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[derive(Debug)] /// Struct representing a SQL-INSERT Query /// A simple query to select everything from a table can be created like this: /// /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// // create the query /// let query = SelectQuery::select(&["*"]).from("users"); /// /// // make sure it looks like you would expect it to look /// assert_eq!(query.as_string(), "SELECT * FROM users"); /// ``` pub struct SelectQuery<'a, 'c> { select: Vec<&'a str>, from: &'a str, pub whre: Vec<WhereClause<'a, 'c>>, limit: Option<usize>, order_by: Option<OrderBy<'c>> } impl<'a, 'c> Display for SelectQuery<'a, 'c> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[allow(unused_assignments)] impl<'a, 'c> SelectQuery<'a, 'c> { /// Creates a new [`SelectQuery`] that selects data from the row/s `rows` /// /// [`SelectQuery`]: ./struct.SelectQuery.html pub fn select(rows: &[&'a str]) -> SelectQuery<'a, 'c> { SelectQuery { select: rows.to_vec(), from: "", whre: Vec::new(), limit: None, order_by: None, } } /// Sets the table to select from to the value of `t` /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// let q = SelectQuery::select(&["user"]).from("users"); /// /// assert_eq!(q.as_string(), "SELECT user FROM users") /// ``` pub fn from(mut self, t: &'a str) -> Self { self.from = t; self } /// Sets the limit value of the Query to the value of `l` /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// let mut q = SelectQuery::select(&["user"]).from("users"); /// q.limit(12); /// /// assert_eq!(q.as_string(), "SELECT user FROM users LIMIT 12") /// ``` pub fn limit(&mut self, l: usize) { self.limit = Some(l); } /// Return whether or not the [`SelectQuery`] has a limit /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// let mut q = SelectQuery::select(&["user"]).from("users"); /// q.limit(12); /// /// assert!(q.has_limit()); /// /// q.clear_limit(); /// assert!(!q.has_limit()); /// ``` /// [`SelectQuery`]: ./struct.SelectQuery.html pub fn has_limit(&self) -> bool { if let Some(_) = self.limit { return true; } false } /// Returns the value of the Limit of the [`SelectQuery`] if there is one /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// let mut q = SelectQuery::select(&["user"]).from("users"); /// assert_eq!(q.get_limit(), None); /// /// q.limit(12); /// assert_eq!(q.get_limit(), Some(12)); /// ``` /// [`SelectQuery`]: ./struct.SelectQuery.html pub fn get_limit(&self) -> Option<usize> { self.limit } /// Removes the limit from the query /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// let mut q = SelectQuery::select(&["user"]).from("users"); /// /// // set the limit /// q.limit(42); /// assert_eq!(q.as_string(), "SELECT user FROM users LIMIT 42"); /// /// // clear limit /// q.clear_limit(); /// /// assert_eq!(q.as_string(), "SELECT user FROM users"); /// ``` pub fn clear_limit(&mut self) { self.limit = None; } /// Adds a ORDER BY clause to the query pub fn order_by(&mut self, ob: OrderBy<'c>) { self.order_by = Some(ob); } /// Creates the string representation of the query /// ## Example /// /// ``` /// use query_builder::SelectQuery; /// /// let mut q = SelectQuery::select(&["*"]).from("users"); /// /// assert_eq!(q.as_string(), "SELECT * FROM users") /// ``` pub fn as_string(&self) -> String { let mut res: String = String::new(); if !self.select.is_empty() { res = format!("SELECT {}", self.select[0]); if self.select.len() > 1 { for s in self.select[1..].iter() { res = format!("{}, {}", res, s); } } } if self.from.len() > 1 { res = format!("{} FROM {}", res, self.from); } if !self.whre.is_empty() { let c = &self.whre[0]; res = format!("{} {}", res, c.as_string_no_cond_with_prefix()); for clause in &self.whre[1..] { res = format!("{} {}", res, clause); } } if let Some(l) = self.limit { res = format!("{} LIMIT {}", res, l); } if let Some(ref ob) = self.order_by { res = format!("{} {}", res, ob); } res } } #[derive(Debug)] /// Struct representing an SQL Insert Statement /// /// Creating a query that works requires at least to function calls. /// /// ## Examples /// /// ``` /// use query_builder::{InsertQuery, Value}; /// /// // construct the InsertQuery to insert into table 'users' /// let mut q = InsertQuery::into("users"); /// /// // add the value 'jonathan' to be added into the row 'name' /// q.values.insert("name", Value::Varchar("jonathan")); /// /// assert_eq!(q.as_string(), "INSERT INTO users(name) VALUES('jonathan')"); /// ``` /// pub struct InsertQuery<'a> { into: &'a str, /// A map of the values to inserted into the table. /// The map is intended to be <row, value> pub values: BTreeMap<&'a str, Value<'a>>, } impl<'a> Display for InsertQuery<'a> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[allow(unused_assignments)] impl<'a> InsertQuery<'a> { /// Creates a new [`InsertQuery`] that puts data into `table`. /// /// [`InsertQuery`]: ./struct.InsertQuery.html pub fn into(table: &'a str) -> InsertQuery<'a> { InsertQuery { into: table, values: BTreeMap::new(), } } /// Returns a [`String`] that represents the [`InsertQuery`] in a valid SQL statement /// ## Example /// ``` /// use query_builder::{Value, InsertQuery}; /// /// let mut q = InsertQuery::into("users"); /// q.values.insert("name", Value::Varchar("greg")); /// /// assert_eq!(q.as_string(), "INSERT INTO users(name) VALUES('greg')") /// ``` /// /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html /// [`InsertQuery`]: ./struct.InsertQuery.html pub fn as_string(&self) -> String { let mut res = String::new(); let (mut vals, mut vals_list) = (String::new(), String::new()); res = format!("INSERT INTO {}", self.into); if !self.values.is_empty() { let mut keys = self.values.keys(); let key = keys.next().unwrap(); vals = format!("{}", key); vals_list = format!("{}", self.values[key]); for k in keys { vals = format!("{}, {}", vals, k); vals_list = format!("{}, {}", vals_list, self.values[k]); } } format!("{}({}) VALUES({})", res, vals, vals_list) } } #[derive(Debug)] /// Struct representing a SQL Delete Statement pub struct DeleteQuery<'a, 'c> { from: &'a str, pub whre: Vec<WhereClause<'a, 'c>>, limit: Option<usize>, order_by: Option<OrderBy<'c>>, } impl<'a, 'c> Display for DeleteQuery<'a, 'c> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[allow(unused_assignments)] impl<'a, 'c> DeleteQuery<'a, 'c> { /// Return a new [`DeleteQuery`] that deletes data from table `table` /// /// [`DeleteQuery`]: ./struct.DeleteQuery.html pub fn from(table: &'a str) -> DeleteQuery { DeleteQuery { from: table, whre: Vec::new(), limit: None, order_by: None, } } /// Sets the limit of items to delete /// ## Example /// /// ``` /// use query_builder::{DeleteQuery, Value, WhereClause}; /// /// let mut query = DeleteQuery::from("users"); /// // add values to delete /// query.whre.push(WhereClause::new("name", Value::Varchar("gregory"), None)); /// /// // add the limit /// query.limit(1); /// /// // make sure the query looks like expected /// assert_eq!(query.as_string(), "DELETE FROM users WHERE name = 'gregory' LIMIT 1"); /// ``` pub fn limit(&mut self, limit: usize) { self.limit = Some(limit); } /// Returns the limit of the [`DeleteQuery`] /// ## Example /// /// ``` /// use query_builder::{DeleteQuery, Value}; /// /// // create query /// let mut query = DeleteQuery::from("users"); /// /// // set the limit /// query.limit(12); /// /// assert_eq!(query.get_limit(), Some(12)); /// ``` /// /// [`DeleteQuery`]: ./struct.DeleteQuery.html pub fn get_limit(&self) -> Option<usize> { self.limit } /// Removes the limit from the [`DeleteQuery`] /// /// ## Example /// /// ``` /// use query_builder::DeleteQuery; /// /// let mut query = DeleteQuery::from("users"); /// /* add limit to the query */ /// query.limit(12); /// /// assert_eq!(query.get_limit(), Some(12)); /// /// /* clear the limit */ /// query.clear_limit(); /// /// assert_eq!(query.get_limit(), None); /// /// ``` /// [`DeleteQuery`]: ./struct.DeleteQuery.html pub fn clear_limit(&mut self) { self.limit = None; } /// Adds a [`OrderBy`] clause to the query /// /// ## Example /// /// ``` /// use query_builder::{DeleteQuery, OrderBy}; /// /// let mut query = DeleteQuery::from("continents"); /// query.order_by(OrderBy::Row("population")); /// /// assert_eq!(query.as_string(), "DELETE FROM continents ORDER BY population"); /// ``` /// [`OrderBy`]: ./enum.OrderBy.html pub fn order_by(&mut self, ob: OrderBy<'c>) { self.order_by = Some(ob); } /// Returns either `true` or `false` depending on whether /// or not the [`DeleteQuery`] contains a [`OrderBy`] clause /// /// ## Example /// /// ``` /// use query_builder::{DeleteQuery, OrderBy}; /// /// let mut query = DeleteQuery::from("states"); /// query.order_by(OrderBy::Row("population")); /// /// assert!(query.is_ordered()); /// ``` /// [`DeleteQuery`]: ./struct.DeleteQuery.html /// [`OrderBy`]: ./enum.OrderBy.html pub fn is_ordered(&self) -> bool { if let Some(_) = self.order_by { true } else { false } } /// Removes the ORDER BY clause from the query pub fn clear_order_by(&mut self) { self.order_by = None; } /// Return a [`String`] representing the [`DeleteQuery`] /// /// ## Example /// ``` /// use query_builder::{DeleteQuery, Value, WhereClause, Condition}; /// /// // create basic query /// let mut query = DeleteQuery::from("people"); /// /// // set parameter of the query /// query.whre.push(WhereClause::new("name", Value::Varchar("justine"), None)); /// query.whre.push(WhereClause::new("age", Value::Int(24), Some(Condition::And))); /// query.limit(1); /// /// assert_eq!(query.as_string(), "DELETE FROM people WHERE name = 'justine' AND age = 24 LIMIT 1"); /// ``` /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html pub fn as_string(&self) -> String { let mut res = String::new(); res = format!("DELETE FROM {}", self.from); if !self.whre.is_empty() { /* get the first element from the vector */ let c = &self.whre[0]; res = format!("{} {}", res, c.as_string_no_cond_with_prefix()); for clause in &self.whre[1..] { res = format!("{} {}", res, clause); } } if let Some(ref o) = self.order_by { res = format!("{} {}", res, o); } if let Some(l) = self.limit { res = format!("{} LIMIT {}", res, l); } res } } #[derive(Debug)] /// Struct representing an SQL Update statement pub struct UpdateQuery<'a, 'c> { update: &'a str, /// A Map containing the field to set with the appropiate values to them pub set: BTreeMap<&'a str, Value<'c>>, /// All [`WhereClause`]s for conditional Updating in this /// [`UpdateQuery`] /// /// [`WhereClause`]: ./struct.WhereClause.html /// [`UpdateQuery`]: ./struct.UpdateQuery.html pub whre: Vec<WhereClause<'a, 'c>>, limit: Option<usize>, } impl<'a, 'c> Display for UpdateQuery<'a, 'c> { fn fmt(&self, f: &mut Formatter) -> FormatResult { write!(f, "{}", self.as_string()) } } #[allow(unused_assignments)] impl<'a, 'c> UpdateQuery<'a, 'c> { /// Returns a new [`UpdateQuery`] that updates the table `table` /// /// ## Example /// /// ``` /// use query_builder::UpdateQuery; /// /// let query = UpdateQuery::update("town"); /// /// assert_eq!(query.as_string(), "UPDATE town"); /// ``` /// /// [`UpdateQuery`]: ./struct.UpdateQuery.html pub fn update(table: &'a str) -> UpdateQuery { UpdateQuery { update: table, set: BTreeMap::new(), whre: Vec::new(), limit: None, } } /// Set the limit of the Query to the value of `l` /// ## Example /// /// ``` /// use query_builder::{UpdateQuery, Value}; /// /// let mut query = UpdateQuery::update("users"); /// // set the limit /// query.limit(12); /// /// // assert that the limit is actually there /// assert_eq!(query.get_limit(), Some(12)) /// ``` pub fn limit(&mut self, l: usize) { self.limit = Some(l); } /// Returns whether or not the [`UpdateQuery`] has a limit /// /// ## Example /// /// ``` /// use query_builder::UpdateQuery; /// /// // create the query /// let mut query = UpdateQuery::update("cities"); /// /// assert_eq!(query.has_limit(), false); /// /// // set limit /// query.limit(1); /// assert_eq!(query.has_limit(), true); /// ``` /// [`UpdateQuery`]: ./struct.UpdateQuery.html pub fn has_limit(&self) -> bool { if let Some(_) = self.limit { return true; } false } /// Returns the limit of the [`UpdateQuery`] if there is one /// /// ## Example /// /// ``` /// use query_builder::UpdateQuery; /// // create the query /// let mut query = UpdateQuery::update("countries"); /// /// assert_eq!(query.get_limit(), None); /// /// // set the limit /// query.limit(12); /// assert_eq!(query.get_limit(), Some(12)); /// ``` /// [`UpdateQuery`]: ./struct.UpdateQuery.html pub fn get_limit(&self) -> Option<usize> { self.limit } /// Returns the [`String`] representation of the [`UpdateQuery`] /// /// ## Example /// /// ``` /// use query_builder::{UpdateQuery, Value}; /// /// let mut query = UpdateQuery::update("users"); /// /// query.set.insert("name", Value::Varchar("jeff")); /// query.limit(1); /// /// assert_eq!(query.as_string(),"UPDATE users SET name = 'jeff' LIMIT 1"); /// ``` /// [`UpdateQuery`]: ./struct.UpateQuery.html /// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html pub fn as_string(&self) -> String { let mut res = String::new(); res = format!("UPDATE {}", self.update); if !self.set.is_empty() { let mut keys = self.set.keys(); let key = keys.next().unwrap(); res = format!("{} SET {} = {}", res, key, self.set[key]); for k in keys { res = format!("{}, {} = {}", res, k, self.set[k]); } } if !self.whre.is_empty() { let c = &self.whre[0]; res = format!("{} {}", res, c.as_string_no_cond_with_prefix()); for clause in &self.whre[1..] { res = format!("{} {}", res, clause); } } if let Some(l) = self.limit { res = format!("{} LIMIT {}", res, l); } res } }