Class: MagicQuery::Schema::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/magic_query/schema/parser.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sql_schema) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/magic_query/schema/parser.rb', line 10

def initialize(sql_schema)
  @sql_schema = sql_schema.to_s
end

Class Method Details

.parse(sql_schema) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 6

def self.parse(sql_schema)
  new(sql_schema).parse
end

Instance Method Details

#add_column(line, tables, current_table) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 73

def add_column(line, tables, current_table)
  column_info = parse_column(line)
  tables[current_table][:columns] << column_info if column_info
end

#add_constraint(line, tables, current_table) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 78

def add_constraint(line, tables, current_table)
  tables[current_table][:constraints] << line
end

#column_definition?(line) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magic_query/schema/parser.rb', line 61

def column_definition?(line)
  line.match?(/^\w+/)
end

#constraint?(line) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magic_query/schema/parser.rb', line 65

def constraint?(line)
  line.match?(/(PRIMARY KEY|FOREIGN KEY|UNIQUE|INDEX)/i)
end

#create_table?(line) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magic_query/schema/parser.rb', line 57

def create_table?(line)
  line.match?(/CREATE\s+TABLE/i)
end

#end_of_table?(line) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magic_query/schema/parser.rb', line 69

def end_of_table?(line)
  line.match?(/\);?$/)
end

#handle_column(line, tables, current_table) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 47

def handle_column(line, tables, current_table)
  add_column(line, tables, current_table)
  current_table
end

#handle_constraint(line, tables, current_table) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 52

def handle_constraint(line, tables, current_table)
  add_constraint(line, tables, current_table)
  current_table
end

#handle_create_table(line, tables) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 41

def handle_create_table(line, tables)
  extract_table_name(line).tap do |table_name|
    tables[table_name] = { columns: [], constraints: [] }
  end
end

#parse ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 14

def parse
  tables = {}
  current_table = nil

  @sql_schema.lines.each do |line|
    line = line.strip
    next if skip_line?(line)

    current_table = process_line(line, tables, current_table)
  end

  tables
end

#process_line(line, tables, current_table) ⇒ Object 



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# File 'lib/magic_query/schema/parser.rb', line 32

def process_line(line, tables, current_table)
  return handle_create_table(line, tables) if create_table?(line)
  return handle_column(line, tables, current_table) if current_table && column_definition?(line)
  return handle_constraint(line, tables, current_table) if current_table && constraint?(line)
  return nil if end_of_table?(line)

  current_table
end

#skip_line?(line) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magic_query/schema/parser.rb', line 28

def skip_line?(line)
  line.empty? || line.start_with?('--')
end