Struct sql_query_builder::Select

pub struct Select { /* private fields */ }

Builder to contruct a Select command

Implementations

impl Select

pub fn as_string(&self) -> String

Gets the current state of the Select and returns it as string

Example

let select_query = sql::Select::new()
  .select("id")
  .from("users")
  .where_clause("login = 'foo'")
  .as_string();

Output

SELECT id FROM users WHERE login = 'foo'

pub fn debug(self) -> Self

Prints the current state of the Select to the standard output in a more ease to read version. This method is useful to debug complex queries or just print the generated SQL while you type

Example

let select = sql::Select::new()
  .select("*")
  .from("users")
  .where_clause("login = foo")
  .where_clause("active = true")
  .debug();

Prints to the standard output

-- ------------------------------------------------------------------------------
SELECT *
FROM users
WHERE login = foo AND active = true
-- ------------------------------------------------------------------------------

You can debug different parts of the select putting it in another position

Example

let select_query = sql::Select::new()
  .select("*")
  .from("users")
  .debug()
  .where_clause("login = foo")
  .where_clause("active = true")
  .as_string();

Prints to the standard output

-- ------------------------------------------------------------------------------
SELECT *
FROM users
-- ------------------------------------------------------------------------------

pub fn from(self, tables: &str) -> Self

The from clause

Example

let select = sql::Select::new()
  .from("users");

pub fn group_by(self, column: &str) -> Self

The group by clause

Example

let select = sql::Select::new()
  .group_by("id");

pub fn having(self, condition: &str) -> Self

The having clause

Example

let select_query = sql::Select::new()
  .group_by("status")
  .having("status != 'disabled'")
  .as_string();

Output

GROUP BY status HAVING status != 'disabled'

pub fn cross_join(self, table: &str) -> Self

The cross join clause

Example

let select_query = sql::Select::new()
  .from("users")
  .cross_join("addresses")
  .as_string();

Output

FROM users CROSS JOIN addresses

pub fn inner_join(self, table: &str) -> Self

The inner join clause

Example

let select_query = sql::Select::new()
  .from("users")
  .inner_join("addresses on addresses.user_login = users.login")
  .as_string();

Output

FROM users INNER JOIN addresses on addresses.user_login = users.login

pub fn left_join(self, table: &str) -> Self

The left join clause

Example

let select_query = sql::Select::new()
  .from("users")
  .left_join("addresses on addresses.user_login = users.login")
  .as_string();

Output

FROM users LEFT JOIN addresses on addresses.user_login = users.login

pub fn right_join(self, table: &str) -> Self

The right join clause

Example

let select_query = sql::Select::new()
  .from("users")
  .right_join("addresses on addresses.user_login = users.login")
  .as_string();

Output

FROM users RIGHT JOIN addresses on addresses.user_login = users.login

pub fn new() -> Self

Creates instance of the Select command

pub fn order_by(self, column: &str) -> Self

The order by clause

Example

let select = sql::Select::new()
  .select("name, login")
  .order_by("login asc");

pub fn print(self) -> Self

Prints the current state of the Select to the standard output similar to debug method, the difference is that this method prints in one line.

pub fn raw(self, raw_sql: &str) -> Self

Adds at the beginning a raw SQL query.

Example

let raw_query = "select * from users";
let select_query = sql::Select::new()
  .raw(raw_query)
  .where_clause("users.login = 'foo'")
  .as_string();

Output

select * from users WHERE users.login = 'foo'

pub fn raw_after(self, clause: SelectClause, raw_sql: &str) -> Self

Adds a raw SQL query after a specified clause.

Example

let raw_join = "inner join addresses addr on u.login = addr.owner_login";
let select_query = sql::Select::new()
  .from("users u")
  .raw_after(sql::SelectClause::From, raw_join)
  .where_clause("u.login = foo")
  .as_string();

Output

FROM users u
inner join addresses addr on u.login = addr.owner_login
WHERE u.login = foo

pub fn raw_before(self, clause: SelectClause, raw_sql: &str) -> Self

Adds a raw SQL query before a specified clause.

Example

let raw_query = "from users";
let select_query = sql::Select::new()
  .raw_before(sql::SelectClause::Where, raw_query)
  .where_clause("users.login = 'foo'")
  .as_string();

Output

from users
WHERE users.login = 'foo'

pub fn select(self, column: &str) -> Self

The select clause

Example

let select = sql::Select::new()
  .select("count(id)");

pub fn where_clause(self, condition: &str) -> Self

The where clause, this method will concatenate mulltiples calls using the and operator. If you intended to use the or operator you should use the where_or method

Example

let select_query = sql::Select::new()
  .where_clause("login = $1")
  .where_clause("status = 'active'")
  .as_string();

Outputs

WHERE
  login = $1
  AND status = 'active'

pub fn where_or(self, condition: &str) -> Self

The where clause that concatenate multiples calls using the OR operator. If you intended to use the and operator you should use the where_clause method

Example

let select_query = sql::Select::new()
  .where_clause("login = 'foo'")
  .where_or("login = 'bar'")
  .as_string();

Output

WHERE
  login = 'foo'
  OR login = 'bar'

Example

let select_query = sql::Select::new()
  .where_clause("login = 'foo'")
  .where_or("login = 'bar'")
  .where_clause("login = 'joe'")
  .as_string();

Output

WHERE
  login = 'foo'
  OR login = 'bar'
  AND login = 'joe'

Example

If the where_or was the first clause then the operator will be ignored

let select_query = sql::Select::new()
  .where_or("login = 'joe'")
  .where_clause("login = 'foo'")
  .as_string();

Output

WHERE
  login = 'joe'
  AND login = 'foo'

impl Select

pub fn except(self, select: Self) -> Self

The except clause, this method can be used enabling a feature flag

Example

let select_users = sql::Select::new()
  .select("login")
  .from("users");

let select_inactives = sql::Select::new()
  .select("login")
  .from("users")
  .where_clause("status = 'inactive'");

let select_query = select_users.except(select_inactives).as_string();

Output

(SELECT login FROM users)
EXCEPT
(SELECT login FROM users WHERE status = 'inactive')

pub fn intersect(self, select: Self) -> Self

The intersect clause, this method can be used enabling a feature flag

Example

let select_users = sql::Select::new()
  .select("login")
  .from("users");

let select_inactives = sql::Select::new()
  .select("login")
  .from("users")
  .where_clause("status = 'inactive'");

let select_query = select_users.intersect(select_inactives).as_string();

Output

(SELECT login FROM users)
INTERSECT
(SELECT login FROM users WHERE status = 'inactive')

pub fn limit(self, num: &str) -> Self

The limit clause, this method overrides the previous value, this method can be used enabling a feature flag

Example

let select = sql::Select::new()
  .limit("123");

let select = sql::Select::new()
  .limit("1000")
  .limit("123");

pub fn offset(self, num: &str) -> Self

The offset clause, this method overrides the previous value, this method can be used enabling a feature flag

Example

let select = sql::Select::new()
  .offset("1500");

let select = sql::Select::new()
  .offset("1000")
  .offset("1500");

pub fn union(self, select: Self) -> Self

The union clause, this method can be used enabling a feature flag

Example

let select_users = sql::Select::new()
  .select("login")
  .from("users");

let select_inactives = sql::Select::new()
  .select("login")
  .from("users")
  .where_clause("status = 'inactive'");

let select_query = select_users.union(select_inactives).as_string();

Output

(SELECT login FROM users)
UNION
(SELECT login FROM users WHERE status = 'inactive')

pub fn with(self, name: &str, query: impl WithQuery + 'static) -> Self

The with clause, this method can be used enabling a feature flag

Example

let logins = sql::Select::new()
  .select("login")
  .from("users")
  .where_clause("id in ($1)");

let select = sql::Select::new()
  .with("logins", logins)
  .select("name, price")
  .from("orders")
  .where_clause("owner_login in (select * from logins)")
  .debug();

Prints to the standard output

-- ------------------------------------------------------------------------------
WITH
logins AS (
  SELECT login
  FROM users
  WHERE id in ($1)
)
SELECT name, price
FROM orders
WHERE owner_login in (select * from logins)
-- ------------------------------------------------------------------------------

Trait Implementations

impl Clone for Select

fn clone(&self) -> Select

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Select

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Select

fn default() -> Select

Returns the “default value” for a type.

impl Display for Select

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.