Returns array of hashes representing result sets.

Jennifer::Query["contacts"].where { _id == 1 }.db_results # => [{"id" => 1, "name" => "Name", ...}]

Decrements specified fields by given value.

For more details take a look at #increment.

Decrements specified fields by given value.

For more details take a look at #increment.

Delete all records which satisfy given conditions.

No model callbacks or validation will be executed.

Jennifer::Query["contacts"].where { _name.like("%dan%") }.delete

Yields each matched record to a block.

To iterate over records they are loaded from the DB so this may effect memory usage. Prefer #find_each.

Yields each result set object to a block.

Returns whether any record satisfying given conditions exists.

Jennifer::Query["contacts"].where { _name.like("%dan%") }.exists?

Returns query execution explanation.

Format depends on used database adapter.

Jennifer::Query["contacts"].explain # => "Seq Scan on contacts  (cost=0.00..13.40 rows=340 width=206)"

Yields each record in batches from #find_in_batches.

Looping through a collection of records from the database is very inefficient since it will instantiate all the objects at once. In that case batch processing methods allow you to work with the records in batches, thereby greatly reducing memory consumption.

Jennifer::Query["contacts"].where { _age > 21 }.find_each("id") do |contact|
  puts contact.id
end

Yields each batch of records that was found by the specified query.

Jennifer::Query["contacts"].where { _age > 21 }.find_in_batches("id") do |batch|
  batch.each do |contact|
    puts contact.id
  end
end

To get each record one by one use #find_each instead.

NOTE any given ordering will be ignored and query will be reordered based on the primary_key and direction.

Executes a custom SQL query against DB and returns array of Record.

Any query conditions specified earlier are ignored.

query = "SELECT name FROM users WHERE age > %1"
Jennifer::Query["contacts"].find_records_by_sql(query, [21]) # [<Record: name="Roland">]

Returns first matched record or nil.

Doesn't modify query instance.

Contact.where { _city_id == 3 }.first

Returns first matched record or raise RecordNotFound exception otherwise.

Doesn't modify query instance.

Contact.where { _city_id == 3 }.first!

Returns array of record ids.

This method requires model to have field id : Int32.

Increments specified fields by given value.

Contact.all.increment({:likes => 1})

No validation or callback is invoked.

Increments specified fields by given value.

Contact.all.increment(likes: 1)

No validation or callback is invoked.

Creates new record in a database with given fields and values.

Ignores any model callbacks.

Jennifer::Query["contacts"].insert(%w(name age), [["John", 60], ["Chris", 40]])

Creates new record in a database with given options.

Ignores any model callbacks.

Jennifer::Query["contacts"].insert({name: "John", age: 60})

Returns last matched record or nil.

Doesn't modify query instance.

Contact.where { _city_id == 3 }.last

Returns last matched record or raise RecordNotFound exception otherwise.

Doesn't modify query instance.

Contact.where { _city_id == 3 }.last!

Returns array of given field values.

This method allows you load only those fields you need without loading records. If query is ModelQuery - take into consideration that fields will not be converted by model converters.

Contact.all.limit(2).pluck([:id, :name]) # [[1, "Name 1"], [2, "Name 2"]]

Returns array of Record created based on result sets.

Jennifer::Query["contacts"].where { _id == 1 }.results
# => [Jennifer::Record(@attributes={"id" => 1, "name" => "Name", ...})]

Alias for #results.

Updates specified fields by given value retrieved from the block.

Expects block to return Hash(Symbol, DBAny | Jennifer::QueryBuilder::Statement).

Contact.all.where { and(_name == "Jon", age > 100) }.update { {:name => "John", :age => _age - 15} }

Updates records with given options.

Contact.all.where { and(_name == "Jon", age > 100) }.update({:name => "John", :age => 40})

Updates records with given options.

Contact.all.where { and(_name == "Jon", age > 100) }.update(name: "John", age: 40)

Inserts given values and ignores ones that would cause a duplicate values of UNIQUE index on given unique_fields.

Some RDBMS (like MySQL) doesn't require specifying exact constraint to be violated, therefore unique_fields argument by default is [] of String.

Jennifer::Query["orders"].insert({:name => "Order 1", :uid => 123})
# the first record will be skipped
Jennifer::Query["orders"].upsert(%w(name uid), [["Order 1", 123], ["Order 2", 321]], %w(uid))

Inserts given values modifies existing row using hash returned by the block.

Some RDBMS (like MySQL) doesn't require specifying exact constraint to be violated, therefore unique_fields argument by default is [] of String.

Jennifer::Query["orders"].insert({:name => "Order 1", :uid => 123, :value => 2})
# the first record will be skipped
Jennifer::Query["orders"].upsert(%w(name uid value), [["Order 1", 123, 3], ["Order 2", 321, 4]], %w(uid)) do
  {:value => values(:value) + _value}
end