Class: SqlParser

Inherits:
Object
  • Object
show all
Defined in:
app/sql_parser.rb

Overview

Used to parse strings containing one or more SQL statements.

Class Method Summary collapse

Class Method Details

.find_statement_at_cursor(sql, cursor) ⇒ Object 



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# File 'app/sql_parser.rb', line 7

def self.find_statement_at_cursor(sql, cursor)
  parts_with_ranges = parse(sql)
  part_with_range = parts_with_ranges.find do |current|
    cursor >= current[1] && cursor <= current[2]
  end || parts_with_ranges[-1]
  part_with_range[0]
end

.parse(sql) ⇒ Object 



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# File 'app/sql_parser.rb', line 19

def self.parse(sql)
  scanner = StringScanner.new(sql)
  statements = []
  single_quoted = false
  double_quoted = false
  single_commented = false
  multi_commented = false
  escaped = false
  current = ''
  start = 0
  until scanner.eos?
    current ||= ''
    char = scanner.getch
    current += char

    if (single_quoted || double_quoted) && !escaped && char == "'" && scanner.peek(1) == "'"
      current += scanner.getch
    elsif escaped
      escaped = false
    elsif !single_quoted && !double_quoted && !escaped && !single_commented && char == '/' && scanner.peek(1) == '*'
      current += scanner.getch
      multi_commented = true
    elsif multi_commented && char == '*' && scanner.peek(1) == '/'
      multi_commented = false
    elsif multi_commented || (single_commented && char != "\n")
      next
    elsif !single_quoted && !double_quoted && !escaped && !multi_commented &&
          char == '-' && scanner.peek(2).match?(/-[ \n\t]/)
      current += scanner.getch
      single_commented = true
    elsif !single_quoted && !double_quoted && !escaped && !multi_commented && char == '#'
      single_commented = true
    elsif single_commented && char == "\n"
      single_commented = false
    elsif single_commented
      single_commented = false if char == "\n"
    elsif char == '\\'
      escaped = true
    elsif char == "'"
      single_quoted = !single_quoted unless double_quoted
    elsif char == '"'
      double_quoted = !double_quoted unless single_quoted
    elsif char == ';' && !single_quoted && !double_quoted
      # Include trailing whitespace if it runs to end of line
      current += scanner.scan(/[ \t]*(?=\n)/) || ''

      # Include an optional trailing single line comma
      current += scanner.scan(/[ \t]*--[ \t][^\n]*/) || ''
      current += scanner.scan(/[ \t]*#[^\n]*/) || ''

      # Include any following blank lines, careful to avoid the final newline in case it is the start of a new query
      while (more = scanner.scan(/\n[ \t]*(?=\n)/))
        current += more
      end

      # Include remaining whitespace if that's all that's left
      if scanner.rest_size == scanner.match?(/[ \t\n]*/)
        current += scanner.rest
        scanner.terminate
      end
      statements << [current, start, scanner.pos]
      start = scanner.pos
      current = nil
    end
  end
  statements << [current, start, scanner.pos] unless current.nil?
  statements
end

.split(sql) ⇒ Object 



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# File 'app/sql_parser.rb', line 15

def self.split(sql)
  parse(sql).map(&:first)
end