Struct sql_query_builder::AlterTable

pub struct AlterTable { /* private fields */ }

Builder to contruct a AlterTable command

Basic API

use sql_query_builder as sql;

let query = sql::AlterTable::new()
  .alter_table("users")
  .add("COLUMN id serial primary key")
  .add("COLUMN login varchar(40) not null")
  .drop("CONSTRAINT users_login_key")
  .as_string();

Output (indented for readability)

ALTER TABLE users
  ADD COLUMN id serial primary key,
  ADD COLUMN login varchar(40) not null,
  DROP CONSTRAINT users_login_key

Implementations

impl AlterTable

pub fn add(self, add_exp: &str) -> Self

Adds columns or table constraints. Multiples call of this method will build the SQL respecting the order of the calls

Example

let query = sql::AlterTable::new()
  .add("COLUMN age int not null")
  .add("CONSTRAINT age check(age >= 0)")
  .as_string();

Outputs

ADD COLUMN age int not null,
ADD CONSTRAINT age check(age >= 0)

pub fn alter_table(self, table_name: &str) -> Self

Defines the name of the table to be altered, this method overrides the previous value

Example

let query = sql::AlterTable::new()
  .alter_table("users")
  .as_string();

Outputs

ALTER TABLE users

pub fn as_string(&self) -> String

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

Example

let query = sql::AlterTable::new()
  .alter_table("users")
  .rename_to("users_old")
  .as_string();

Output

ALTER TABLE users RENAME TO users_old

pub fn debug(self) -> Self

Prints the current state of the AlterTable 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 query = sql::AlterTable::new()
  .alter_table("users")
  .add("name varchar(100) not null")
  .add("login varchar(40) not null")
  .add("constraint users_login_key unique(login)")
  .debug()
  .as_string();

Prints to the standard output

-- ------------------------------------------------------------------------------
ALTER TABLE users
  ADD name varchar(100) not null,
  ADD login varchar(40) not null,
  ADD constraint users_login_key unique(login)
-- ------------------------------------------------------------------------------

pub fn drop(self, drop_exp: &str) -> Self

Drops columns or table constraints. Multiples call of this method will build the SQL respecting the order of the calls

Example

let query = sql::AlterTable::new()
  .drop("column login")
  .as_string();

Outputs

DROP column login

pub fn new() -> Self

Creates instance of the AlterTable command

pub fn print(self) -> Self

Prints the current state of the AlterTable 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. Is useful to create a more complex alter table signature like the example below.

Example

let create_table_query = sql::AlterTable::new()
  .raw("ALTER TABLE IF EXISTS users")
  .drop("legacy_column")
  .as_string();

Output

ALTER TABLE IF EXISTS users DROP legacy_column

pub fn raw_after(self, param: AlterTableAction, raw_sql: &str) -> Self

Adds a raw SQL query after a specified parameter.

Example

let raw = "ADD COLUMN name varchar(100) not null";

let query = sql::AlterTable::new()
  .alter_table("users")
  .raw_after(sql::AlterTableAction::AlterTable, raw)
  .as_string();

Output

ALTER TABLE users ADD COLUMN name varchar(100) not null

pub fn raw_before(self, action: AlterTableAction, raw_sql: &str) -> Self

Adds a raw SQL query before a specified parameter.

Example

let raw = "ALTER TABLE users";

let query = sql::AlterTable::new()
  .raw_before(sql::AlterTableAction::AlterTable, raw)
  .add("COLUMN id")
  .as_string();

Output

ALTER TABLE users RENAME TO users_old

impl AlterTable

pub fn rename(self, rename_exp: &str) -> Self

Available on crate features postgresql and sqlite only.

Changes the column names or table constraints. Multiples call of this method will build the SQL respecting the order of the calls

Example

 let query = sql::AlterTable::new()
   .alter_table("users")
   .rename("COLUMN address TO city")
   .to_string();

Outputs

ALTER TABLE users RENAME COLUMN address TO city

pub fn rename_to(self, table_name: &str) -> Self

Available on crate features postgresql and sqlite only.

Changes the name of the table

Example

let query = sql::AlterTable::new()
  .alter_table("users")
  .rename_to("users_old")
  .to_string();

Outputs

ALTER TABLE users RENAME TO users_old

impl AlterTable

pub fn alter(self, alter_exp: &str) -> Self

Available on crate feature postgresql only.

Alter columns or table constraints. Multiples call of this method will build the SQL respecting the order of the calls

Example

 let query = sql::AlterTable::new()
   .alter("COLUMN created_at SET DEFAULT now()")
   .to_string();

Outputs

ALTER COLUMN created_at SET DEFAULT now()

Trait Implementations

impl Clone for AlterTable

fn clone(&self) -> AlterTable

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for AlterTable

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

Formats the value using the given formatter.

impl Default for AlterTable

fn default() -> AlterTable

Returns the “default value” for a type.

impl Display for AlterTable

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

Formats the value using the given formatter.