Class: Tina4::Adapters::Sqlite3Adapter

Inherits:
Object
  • Object
show all
Defined in:
lib/tina4/database/sqlite3_adapter.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection_string = nil) ⇒ Sqlite3Adapter

Returns a new instance of Sqlite3Adapter.



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 8

def initialize(connection_string = nil)
  @connection = nil
  @db_path = nil
  @in_transaction = false
  connect(connection_string) if connection_string
end

Instance Attribute Details

#connection ⇒ Object (readonly)

Returns the value of attribute connection.



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 6

def connection
  @connection
end

#db_path ⇒ Object (readonly)

Returns the value of attribute db_path.



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 6

def db_path
  @db_path
end

Instance Method Details

#apply_limit(sql, limit, offset = 0) ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 126

def apply_limit(sql, limit, offset = 0)
  "#{sql} LIMIT #{limit} OFFSET #{offset}"
end

#begin_transaction ⇒ Object

Transaction support



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 90

def begin_transaction
  return if @in_transaction
  @connection.execute("BEGIN TRANSACTION")
  @in_transaction = true
end

#close ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 25

def close
  @connection.close if @connection
  @connection = nil
end

#columns(table) ⇒ Object

Get column metadata for a table



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 66

def columns(table)
  query("PRAGMA table_info(#{table})").map do |r|
    {
      name: r[:name],
      type: r[:type],
      nullable: r[:notnull] == 0,
      default: r[:dflt_value],
      primary_key: r[:pk] == 1
    }
  end
end

#commit ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 96

def commit
  return unless @in_transaction
  @connection.execute("COMMIT")
  @in_transaction = false
end

#connect(connection_string) ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 15

def connect(connection_string)
  require "sqlite3"
  @db_path = connection_string.to_s.sub(/^sqlite3?:\/\//, "").sub(/^sqlite3?:/, "")
  @connection = SQLite3::Database.new(@db_path)
  @connection.results_as_hash = true
  @connection.execute("PRAGMA journal_mode=WAL")
  @connection.execute("PRAGMA foreign_keys=ON")
  self
end

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tina4/database/sqlite3_adapter.rb', line 30

def connected?
  !@connection.nil? && !@connection.closed?
end

#exec(sql, params = []) ⇒ Object

Execute DDL or DML without returning rows



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 51

def exec(sql, params = [])
  @connection.execute(sql, params)
  { affected_rows: @connection.changes }
end

#fetch(sql, limit = 100, offset = nil) ⇒ Object

Paginated fetch



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 41

def fetch(sql, limit = 100, offset = nil)
  effective_sql = sql
  if limit
    effective_sql = "#{sql} LIMIT #{limit}"
    effective_sql += " OFFSET #{offset}" if offset && offset > 0
  end
  query(effective_sql)
end

#last_insert_id ⇒ Object

Get last inserted row id



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 85

def last_insert_id
  @connection.last_insert_row_id
end

#placeholder ⇒ Object

Convenience: placeholder for parameterized queries



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 118

def placeholder
  "?"
end

#placeholders(count) ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 122

def placeholders(count)
  (["?"] * count).join(", ")
end

#query(sql, params = []) ⇒ Object

Execute a query and return rows as array of symbol-keyed hashes



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 35

def query(sql, params = [])
  results = @connection.execute(sql, params)
  results.map { |row| symbolize_keys(row) }
end

#rollback ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 102

def rollback
  return unless @in_transaction
  @connection.execute("ROLLBACK")
  @in_transaction = false
end

#table_exists?(table) ⇒ Boolean

Check if a table exists

Returns:

  • (Boolean) 


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# File 'lib/tina4/database/sqlite3_adapter.rb', line 57

def table_exists?(table)
  rows = query(
    "SELECT name FROM sqlite_master WHERE type='table' AND name = ?",
    [table.to_s]
  )
  !rows.empty?
end

#tables ⇒ Object

List all user tables



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 79

def tables
  rows = query("SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'")
  rows.map { |r| r[:name] }
end

#transaction ⇒ Object 



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# File 'lib/tina4/database/sqlite3_adapter.rb', line 108

def transaction
  begin_transaction
  yield self
  commit
rescue => e
  rollback
  raise e
end