class DBI::SQL::PreparedStatement
The PreparedStatement class attempts to provide binding functionality for database systems that do not have this built-in. This package emulates the whole concept of a statement.
Attributes
Public Class Methods
“prepare” a statement.
quoter
is deprecated and will eventually disappear, it is kept
currently for compatibility. It is safe to pass nil to this parameter.
sql
is the statement itself.
# File lib/dbi/sql/preparedstatement.rb, line 25 def initialize(quoter, sql) @quoter, @sql = quoter, sql prepare end
Convenience method for consumers that just need the tokens method.
# File lib/dbi/sql/preparedstatement.rb, line 13 def self.tokens(sql) self.new(nil, sql).tokens end
Public Instance Methods
attempts to bind the arguments in args
to this statement. Will
raise StandardError if there are any extents issues.
# File lib/dbi/sql/preparedstatement.rb, line 62 def bind(args) if @arg_index < args.size raise "Too many SQL parameters" elsif @arg_index > args.size raise "Not enough SQL parameters" end @unbound.each do |res_pos, arg_pos| @result[res_pos] = args[arg_pos] end @result.join("") end
Break the sql string into parts.
This is NOT a full lexer for SQL. It just breaks up the SQL string enough so that question marks, double question marks and quoted strings are separated. This is used when binding arguments to “?” in the SQL string.
C-style ( ) and Ada-style (–) comments are handled.
- Note
-
Nested C-style comments are NOT handled!
# File lib/dbi/sql/preparedstatement.rb, line 40 def tokens @sql.scan(%r{ ( -- .* (?# matches "--" style comments to the end of line or string ) | - (?# matches single "-" ) | /[*] .*? [*]/ (?# matches C-style comments ) | / (?# matches single slash ) | ' ( [^'\] | '' | \. )* ' (?# match strings surrounded by apostophes ) | " ( [^"\] | "" | \. )* " (?# match strings surrounded by " ) | \?\?? (?# match one or two question marks ) | [^-/'"?]+ (?# match all characters except ' " ? - and / ) )}x).collect {|t| t.first} end