class CQL::Update

Reference < Object

The CQL::Update class represents an SQL UPDATE statement.

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

Usage

• initialize(schema : Schema) - Initializes a new instance of CQL::Update with the given schema.

• commit : DB::Result - Executes the update query and returns the result.

• to_sql(gen = @schema.gen) : {String, Array(DB::Any)} - Generates the SQL query and parameters.

• table(table : Symbol) : self - Sets the table to update.

• set(setters : Hash(Symbol, DB::Any)) : self - Sets the column values to update using a hash.

• set(**fields) : self - Sets the column values to update using keyword arguments.

• where(&block) : self - Sets the WHERE clause using a block.

• where(**fields) : self - Sets the WHERE clause using keyword arguments.

• back(*columns : Symbol) : self - Sets the columns to return after the update.

• build : Expression::Update - Builds the Expression::Update object. details Table of Contents [[toc]]

Constructors

def new(schema : Schema)

Instance Methods

def back(*columns : Symbol)

Sets the columns to return after the update.

• @param columns [Array(Symbol)] the columns to return

• @return [self] the current instance

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .back(:name, :age)
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3 RETURNING name, age", ["John", 30, 1]}

def build

Builds the Expression::Update object.

• @return [Expression::Update] the update expression

• @raise [Exception] if the table is not set

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def commit

Executes the update query and returns the result.

• @return [DB::Result] the result of the query

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def set(setters : Hash(Symbol, DB::Any))

Sets the column values to update using a hash.

• @param setters [Hash(Symbol, DB::Any)] the column values to update

• @return [self] the current instance

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def set

Sets the column values to update using keyword arguments.

• @param fields [Hash(Symbol, DB::Any)] the column values to update

• @return [self] the current instance

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def table(table : Symbol)

Sets the table to update.

• @param table [Symbol] the name of the table

• @return [self] the current instance

• @raise [Exception] if the table does not exist

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def to_sql(gen = @schema.gen)

Generates the SQL query and parameters.

• @param gen [Expression::Generator] the generator to use

• @return [{String, Array(DB::Any)}] the query and parameters

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .to_sql

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def where

Sets the WHERE clause using a block.

• @block w [Expression::FilterBuilder] the filter builder

• @return [self] the current instance

• @raise [Exception] if the block is not provided

• @raise [Exception] if the block does not return an expression

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}

def where(attr : Hash(Symbol, DB::Any))

Sets the columns to return after the update.

• @param columns [Array(Symbol)] the columns to return

• @return [self] the current instance

• @raise [Exception] if the column does not exist

• @raise [Exception] if the column is not part of the table

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where { |w| w.id == 1 }
  .back(:name, :age)
  .commit

def where

Sets the WHERE clause using keyword arguments.

• @param fields [Hash(Symbol, DB::Any)] the conditions

• @return [self] the current instance

• @raise [Exception] if the column does not exist

• @raise [Exception] if the value is invalid

Example

update = CQL::Update.new(schema)
  .table(:users)
  .set(name: "John", age: 30)
  .where(id: 1)
  .commit

=> {"UPDATE users SET name = $1, age = $2 WHERE id = $3", ["John", 30, 1]}